Today at Atco i got to try the car out with the Line Lock, New carb, and locked out timing.

My best pass of the day was an 11.60 @ 117.31 mph

And my best 60ft was a 1.61

Not too bad for a pump gas street 385" motor, eh :D

I think i was walking on clouds today!

Thats Small Block BSE Power!

Brian ,Alow me to be the first here. graemlins/thumbsup.gif graemlins/hurray.gif That's great.I can't wait to try out my new toys now. :D

MY VELLE (http://www.chevelles.com/showroom/onebadd66/DSCF0010.JPG)

Congrats Brian, got a rollbar in that car yet? :D

:cool: Nice pick up over your previous best! What carb did you switch to and what was the weather like. 1/2sec gain is nice!

That's great, Brian! graemlins/hurray.gif
I'm jealous of the 60' times...

Thanks guys!

John, the carb is a 700 double pumper, with a 750 proform Body.
73 jetting with a PV in the front and 83 in the rear.
Red/Brown pump cams.

What do you think improved your ET the most? The locked out timing or the carb change? Or was it just a combination of both? I am just curious. I think you picked up 7 mph and .7 or so in ET, that is huge. Nice goin !

impressive.

That is a very impressive change I must say. What does the car weigh now?

Nice job Brian!!

graemlins/thumbsup.gif Very impressive Brian

graemlins/thumbsup.gif

Hard work really paying off..Good to see it.

Wow! Now why didn't I stroke my 350 when I had the chance? graemlins/clonk.gif

Were all the runs smooth? Any misses, snorts, coughs, etc? What do you have planned next? Can you explain how you locked out your timing? I've never tried it.

Geez, mid-to-high 11's. Isn't that quicker than Ed's "BSE blueprint" 396? ;)

BTW, I may email you concerning your line lock installation. How can I get in touch?

Congratulations Brian! Nice going graemlins/thumbsup.gif

Bryan, Those are some very impressive numbers! Congratulations.

Thanks guys!

The car weighs 3260lbs

This combo is pretty quick, but keep in mind Ed's 396 was in a 4000lbs car.

The car pulls hard now, nothing amiss to speak off, other then a wheelhop problem, which i'm currently working on a solution, hopefully that will pick up 60ft.

Justin, you can email me @ holcomb2@tcnj.edu

i'll explain the timing, and the line lock.

Double pumper and locked out timing..........Now you got me thinkin graemlins/thumbsup.gif . Very nice gains indeed, and dialed it down in a hurry. That is truely impressive performance, no doubt that you will squeeze even more out of your combo. I thought I was da man winning trophy class today.........NOT. YOU DA MAN.

Congrats.......

thanks Craig

Locked out timing isnt for everyone, you need to have a good mini-starter, as well a good Group 24 battery.
I use a CSI mini-starter, works great.

The double pumper however is a step in the right direction, as i found out.
The vacuum secondary carbs can be tuned very well, but for bracket racing, and all out performance the double pumper with a Proform main body works very well.

If you added a toggle switch for the igintion, you could help starting. With the switch you can start the motor turning, then flip it on. The motor will fire almost instantly with out any fighting.

Congrats on the times.
Steve

Brian, congrats! 11 sec street cars are the boss! Havent gotten there yet myself, close, but I'm fighting 800 lbs more and a stickshift. Been more street then strip this year.

graemlins/beers.gif

Thanks guys,
I dont need a toggle switch for the ignition, it works fine for me with the CSI starter.

I'm just warning others who might think a GM stock type starter will turn over a locked out timing motor.

Great going guy!!

pdq67

Hey Brian congrads on your new time! I was wondering why a GM starter would be suggested with the timing locked out?

Oh ya you never shared your combo with us. Or maybe I missed that thread.

I'd sure like to run 11's....nice job.

Aaron,
thanks for the compliment.
re-read my post, i wouldn't recommend that a GM standard starter be used with locked out timing.

I tried it on mine, the GM stock starter couldnt handle it.

The CSI turns it over, no problem.

Thanks Dawg and Paul.

Hey guys, way to go brian, you have got one hell of a small block there. I have locked out timing on my 468 and I use a stock GM starter, the key for me was a MSD digital 6 plus ignition box, this box retards the timing 20 degrees until the engine reaches 800 rpm then goes "all in". Its a very nice system and for the price is a nice way to better your ignition and cure the starting problem. Good Luck curing your wheelhop, I can't wait to see how fast your 60' times can get if you figure it out. Good Luck and Good Racin' Jeff

opps I wrote that wrong graemlins/clonk.gif

What I ment is why wouldn't you recomened the GM starter with the timing locked out?

Thanks again
Aaron

thanks guys

If the engine tries to kick back.....which it will......it's easy to break the nose off the starter motor. I've done it. Especially the aluminum nose starters.

A few things to do to help with the kick back problem:

1. Use a VERY good battery.
2. Use very heavy gauge battery cables.
3. Make sure all connections including the grounds are clean and tight.

As someone else mentioned, a seperate switch on the ignition system can be used so that the starter can get the engine spinning before the ignition is turned on.

That said, what is the advantage to locking out the timing?
Personally, I can't see any.

Ron

The only advantage I could see to locked out timing would be for a motor that idles low where you would experience a poor idle due to the mech advance only partially kicking in and out and causing an eratic idle condition. The simple answer is loosen up on the mech advance so it comes in much sooner but still allow you to start the motor on less advance. You set the timing for total timing, so whatever the motor sees in the way of advance at idle becomes irrelevant anyway.

Originally posted by GRN69CHV:
The only advantage I could see to locked out timing would be for a motor that idles low where you would experience a poor idle due to the mech advance only partially kicking in and out and causing an eratic idle condition. The simple answer is loosen up on the mech advance so it comes in much sooner but still allow you to start the motor on less advance. You set the timing for total timing, so whatever the motor sees in the way of advance at idle becomes irrelevant anyway. When your on the ragged edge of cpmpression and timing, the last thing you want/need is any fluctuations<sp>. By locking out the timing you remove any of the varriables. also its nice to adjust your timing at idle smile.gif

Just curious if this was deep staging or shallow, nice 60ft!

Also, can you lock out timing on an HEI with the MSD 6AL running everything? I've got a good mini starter, thinking this is whats hurting my combo a lot. It just wants to advance and keep advancing all the time.

Matt

Locking out his timing is not what made him run such a good ET - it's the well thought out combo that did.

If you drive your car on the street, a properly set up distributor with both mechanical and vacuum advance is the way to do it.

mmmm, I would say it's the light weight and the HP. It's not a miracle.

Matt,

I think what is hurting you could be jetting or total timing.

What jetting/carb do you have, and where is the timing at now?


Todd DelaMuca,
Thanks for the compliment!
I agree that most should fine tune their timing curve, rather then locking out the distributor.
In my case, i like the simplicity.

Brian’s Stroker "Street" Small Block

350 +.040" 4 bolt block 3.75” Stroke crank= 385ci
-SRP Forged Pistons #138094 with Plasma Moly file fit rings
-9.8:1 CR
-350 block .004" deck
-Clevite 77 bearings
-Fel-Pro Gaskets
-Eagle Cask Crank 3.75" Stroke External balance
-Crower Sportsman 6” cap screw Rods ARP main studs
-Milodon louvered Windage tray
-GM Stock oil pan and pickup
-Melling Standard oil pump
-Cloyes true Roller timing set
-World Products Sportsman II 200cc intake port heads 72cc combustion chambers fitted with Race Flo 2.02/1.60 back-cut valves bowl blend
-Performer RPM intake manifold
-Holley 750 with Proform Main Body
73 front jets, with a 5.5" powervalve.
83 rear jets, no rear powervalve.
-4 hole spacer 1/2” tall
-Holley carb Heat Shield
-Crower Cams #00321 (Ground on a 108LSA) Solid Flat tappet 242/248 Dur .050” .482/.504" valve lift Crane double Valve Springs #99893-16
-Rocker Arms- Crower Stainless Steel 1.5
-Comp One Piece .080” wall 5/16” Pushrods
-MSD Ready-to-run Pro Billet Blaster II chrome coil
-Headers- 1-5/8” primary 3” collector, 33” average primary tube length
Merge style collector
-3” head pipe/H style crossover Dynomax Oval UltraFlo mufflers, 3” dumps.
-Carter 172gph mechanical pump plumbed to 3/8" fuel line.
-Mobil 1 5W-30 oil, Ford F-type transmission fluid Coastal 75w-90 Gear oil
-Autolite AR-13 spark plugs
-TH-350 by STR, ATI 10” Treemaster Converter, 4.10 gears Cheetah shifter
-Summit Steel OEM style damper
-Koni Street Adjustable front shocks set full soft
-Moog 6314 springs
16.44” …………………….free height
.601”………………………..wire dia.
289 lbs/in………………..rate
1744………………………..total load

Best ET 11.60 with a 1.61 60ft in a 3260lb 67’ Camaro


...For those interested in the combo.

hey brian, i was curious why you are using the sportsman II's? when there are so many better flowing heads out there, was it because you wanted cast iron and there aren't many to choose from? i know they are a good foundation for a port and resopond well to porting, but it looks like you only gave them a bowl job. well i guess they work good enough for 11's!

Brian what are you shifting at?

6000 rpm shift points, 6100-6200 trap RPM.

Cody, The sportsman II's work fine, and they are iron, which i wanted. They were the cylinder heads used on the BSE small blocks, and i decided it was a good idea to use the same heads on my engine. Although the heads on the BSE small block are the 180cc version.

I worked the bowls, and did a 4 angle valve job.
60/45/30 and a 17.5 degree back cut on the valve.

the valves were the necked down stem.

Its the little things that count, and you find power in the valve job, the bowl blend, the valve selection, as well as the correctly sized port for the RPM range.

Now, i could do a much better valve job, tightening up on the seats and doing 4 angles on the seats, as well as the back cut on the valve.
Maybe even putting the seat at 47 or 48 degrees.

the engine only responds well to porting if you're willing to set the shift points higher as well as select gearing for a higher RPM range.

Even the ports i selected are on the large side for my RPM range.

Hey Brain, thanks for posting your combo and results, that helps me get an idea as to what I want to build for my malibu in the next couple of years.

I like the "BSE 385" combo you have there.

Oh, by the way, can you give me the real answer to what "BSE" stands for?

I've seen the question asked before and have searched, but due to the hostility towards Racer1320, all I've ever seen as an answer is someone BS'ing about it's meaning.

Thanks again for posting that combo. Any Ideas what a combo like that would do in a TH350/3.55 geared steel bodied chevelle?

BSE = Ed "Begley's Special Engine"! And I hope I spelled Ed's last name right?

pdq67

PS., and I am a fan..

Bigley Special Engine.

I consider mine to be a BSE motor because Ed it fallows Ed's basis for making power in the RPM range you use, its a street/strip motor, small tube headers, Iron heads and a dual plane manifold.

Good driving and a good combo. Life doesn't get much sweeter.

What is the time slip break down? I'm mostly interested in the 1/8th, but the other stuff tells a lot too.

It's pretty funny that you and I both took a picture of our ATI converter out of the box. :D "I spent how much money on that thing!?!?" :eek:

Brian, what brand header did you start with?

What head is used with the 180cc intake port version?

thanks mike,

R/T -.021
60' 1.654 (spun a little on this pass)
330' 4.785
1/8 7.402
MPH 93.71
990 9.612
1/4 11.601
MPH 117.31

the best 60ft was also that day, the prior pass, and it was a 1.61


Mark,
I started off with a flowtech header. I'm planning to build a stainless set this winter, stay tuned.

the BSE small block uses the Dart II, in i believe, 180cc.

Would that be equiv. to the 180cc Iron Eagles available today..... I'm pretty sure the "II" designation fell off when they broke away from World?

Also, why is an Iron head specified for a street/strip combo? Would it not be a good idea to build a similar build, with say, AFR 195s?

i would have to disagree about porting heads making higher peak HP, doing a good job at porting a head creates more airflow hopefully at all lift numbers. Porting isn't just hogging out a port

whats a "good" porting job consist of in your opinion?


I look for ways to emphasize power in the RPM range that i use, porting was not needed in my case. Could some port work help? Of course, but i did not want to spend the $1000+ for a quality porting job.

I think i'm doing fine without it, and it might become an option later on, when i've exhausted most of the other routes of finding ET that i have in mind.

Right now i still have plenty of routes of finding more power, and using the power that i have.

Originally posted by Slowpoke70:
Would that be equiv. to the 180cc Iron Eagles available today..... I'm pretty sure the "II" designation fell off when they broke away from World?

Also, why is an Iron head specified for a street/strip combo? Would it not be a good idea to build a similar build, with say, AFR 195s? Hate to quote myself, but I think you missed my questions. Maybe I should tell you what I already know, that way, if you wish to do me a favor, you can add more to my knowledge.

What I know about aluminium heads.

1) An aluminium head doesnt make more power than an exact copy of it made in Iron If it replaces the Iron head and nothing else is changed.
2) They're lighter, of course.
3) They allow you to use a higher CR with less chance of detonation.
4) Easier to repair if you crack one.
5) AFRs are way more expensive than Dart IE's and WP Sportman II.

Thats about it.

Thanks.

Aluminum effectily needs 14:1 compression or more before its attributes become A quality and not a downfall.

....of course in your opinion(not meant to be rude).
i respectifully disagree about the aluminum thing, or the fact that porting your heads won't affect the power in your rpm range (not that this is what this post is about!...off topic), but you make a good point about being able to port the heads in the future, that would make a good A to B comparison! What other plans do you have for the motor to get some better power out of it? i take it just more tuning and minor combo matching?

So basically you're saying that up until 14:1 the Aluminium head is probably going to lose power over the iron head? Is this because of heat dissipation? Or?

i think you should start a new post, this post will get redirected if you don't

That comment is completely unsubstantiated and has no reasonable basis in fact.

On a different note, hey Brian since you work in a engine shop, wonder if your shop boss can come up with a good price on your engine combo and start making them. Seems like it would work in many apps, including street rods. Maybe the market for engineered crate sbc's is too full, I donnow.

Originally posted by Slowpoke70:
So basically you're saying that up until 14:1 the Aluminium head is probably going to lose power over the iron head? Is this because of heat dissipation? Or? =
While I do not agree at all with Brian's statement about 14.0 & aluminum there is a bit if fact there.
If you had two identical heads in every respect the iron head would make more power assuming no detonation etc.

But,,,,, & a very big but,, in almost every case when you buy a set of aluminum heads like AFR, Brodix, GM fast burns etc. they are usually going to have better flow & chamber designs then an iron counterpart & efficient airflow through the smallest head you can run for the RPM you are planning on running your engine to is what makes power regardless of RPM.

If you can get more EFFICIENT airflow into the cylinder it is going to make more power period, again regardless of RPM.
This does not include sticking a sewer pipe sized head on your engine to get more airflow :D

Cody is correct, if you can port the head & make it flow better without making it a hole you might fall into it is going to be capable of making more power at any RPM.

And now,,, back to the original post,,,, Outstanding Brian graemlins/thumbsup.gif
Excellent power with a well thought out combo.
Don't personally know your "Mentor",, but it's pretty obvious you have done learned well ;)

i dont want to start up an aluminum head debate.

thanks for the compliments guys!

thanks Mike!


Gene, i have thought of that, since its a proven combo, maybe next week i'll ask him if he likes the idea.

Cody,
primarily for me, right now, after building a roll bar (fall/winter project)....and getting the thing to consistantly Hook, would be to do timing and jetting loops to find what makes the best MPH/ET.

I have some other plans, but as for right now, nothing is set in stone.

its all about Overfilling the cylinder, and cylinder pressure under dynamic conditions (not to be confused with DCR).
Overfilling the cylinder is directly related to velocity in the intake tract, as well as a correctly sized port for the motor.

In my opinion, aside from choosing the port size to match the RPM band, what it comes down to is an effective shape in the Bowls, along with the valve job, shape of the guide extending into the port as well as other things in that area.

Gene, without getting into a argument here, how is it that you know my comment is unsubstantiated. if you feel you need to make a statement like that, feel free to email me.

With all due respect, i think you are drawing conclusion on my statement before giving it any thought.

While i believe there is little power to be lost with aluminum heads, with what i've seen work, and what questions i've asked, and what answers i've received, I have decided that Iron heads were my best choice.

Brian,
I know you stated you don't want to get into an iron/alum debate BUT...

Elaborate for me and others if you would.

I agree as Wolfplace mentioned that the iron if identical makes more power, all being equal.

But your statement of needing 14-1 to overcome aluminums drawbacks is interesting.

What do you base this on. Scientific or dyno, or drag results by anyone is fine.
I know Ed also state's the same theory, that he would only run aluminum head sin a 14-1+ motor.

I've typically been of the opinion that you would NEED 1 full point of additional compression with aluminum heads to compensate for their thermal "bleeding" as I call it.
So a 10-1 iron headed motor setup as 11-1 with aluminum should be about equal power wise all else being equal.
My basis for this is that normally the aluminum will allow this compression increase before detonation. So they must be bleeding that much heat/power roughly.
Some have disagreed stating that the heat cannot "bleed" that fast at 6000 rpm.
If that were true you would not be able to run the additional compression...

However a "set" number like 14-1 as a decision making factor for head material makes me want to know the basis for the number.

also what is overfilling a cylinder, i didn't think there was such thing as overfilling it, isn't that basically what a supercharger does, or N20? and how does the type of metal of the head lead to overfilling? i agree with you on how the port should be shaped but there is even more to it than the valve guide throat and bowl, the short turn is a highly important equation to the operation of the port and isn't even suggested to be messed with unless you are a prof. and then there is the walls, and of course the chamber is half the battle! and etc....Even though it isn't in Ed's agenda i think he should call around to maybe AFR and Brodix, and try to get a set of their heads for free or cheaper as a good test, they could even use the results as advertising for a tradeoff, he could maybe put them to the test, leaving all things the same, or maybe having them decked enough to raise the compression one whole point. But they would have to be a fair comparison (decent head with flow#'s in the same range as his irons or better) and of course the results would have to be an average of a bunch of runs after tuning with the new heads, i think a CNC'd pair of the Brodix ovals would be good, or a set of the as cast AFR 305's.

Run a higher DCR with alum, that's all. And using a simple static 'estimate' like 14:1 is simply spurious , unless its based on some engineering tests, and even then its DCR that matters.

FOrget about it, iron is as good if not better and most importantly, CHEAPER than alum.

Yes, that's what I meant Brian, an easily replicated proven combo. With fairly low $$$ parts. Could be something you could sell a few of at the right price point. Nice "retro" crate ( being a solid lifter ) for street rods or muscle cars.

Jake,
I will answer that later, as i'm off to island.

Cody,
Pro Stocks have volumetric effeciency over 120% from a N/A 500" Motor, the way to acheive a VE over 120% is to "overfill" the cylinder by creating an Inertia supercharger, in which the Port Cross section is sized perfectly for the engine, along with the correctly chosen cam, and exhaust system, as all have play in creating that effect. With this Inertia super charger, the fuel/air is brought to extremely high velocities and the inertia of the mixture at those speeds helps overfill the cylinder.

As well they Tune the length of the runner to take advantage of pressure waves. when the valve closes it creates a wave, which will travel back up to the carb venturi, then back down the runner, if the length of the runner is the correct Lenght the pressure wave will assist in pulling more air/fuel into the cylinder, thus assisting in overfilling the cylinder.

Even a street/strip motor can create the same effects if the parts are chosen correctly, along with the machine work and specifically the valve job and bowl work done correctly.
As well a correctly sized header primary tube diameter and length as well as a header collector of the right characteristics (Merge, or scavenger style collectors).

As well the carb has a great deal of effect on all of this.

Everything is involved, and everything has an effect.

I've heard more than one person say that DCR is meaningless...anyone care to elaborate?

Yes I will comment. DCR is the CR. that is calculated at the time the intake valve closes!! No more, no less...

It is the amount of charge volume that gets trapped in the cylinder the instant the intake valve physically closes and is VERY important b/c you can't squeeze it until you contain it!!

It also shows the relationship that static compression ratio has with respect to the intake valve closing point b/c as the intake valve closing point gets later in degrees ABDC, there is less charge trapped so in the words of the Smoke, (I think), "if you don't get much in there, you better squeeze hell outta what you do!!"

That's why we need to up the static compression ratio to make up for the drop in dynamic compression ratio that comes about when a big cam is installed. BUT then, all is good at low speeds and such until the motor picks up AND actually becomes eff. enough to use the cam and the higher static compression ratio at speed, b/c then you need a higher octane fuel to keep highspeed detonation from ruining everything, imho...

(How am I doing Pat???)........

This is when the "Fueling Engineering stuff/high compression-87 octane fuel" engine combination motor design theory comes into play.. But the only real world results we have are from the Fueling BB torque head users and they don't post here how they work b/c the heads are designed for 454 duelie work truck motors, not hy-po street machine motors..

Bttt, It always amazes me when somebody works really hard to come up with onna them 268/218 cammed motors that's CR'ed, intaked, headed, headered and tired and geared just right so that it blows the doors off other bigger motor combinations b/c everything works together!!

That or the dude is lying to everybody and pulling the old hotrod trick of pasting on decals and running other unknown/unadvertised hy-po parts in his motor so nobody knows it..

It's been said many times that a small cam AND a real eff. port will run stronger then a big cam and a lousey port!!!

Great thread, please keep it coming..

pdq67

Originally posted by Motor Martyr:
the way to acheive a VE over 120% is to "overfill" the cylinder by creating an Inertia supercharger, in which the Port Cross section is sized perfectly for the engine, along with the correctly chosen cam, and exhaust system, as all have play in creating that effect. With this Inertia super charger, the fuel/air is brought to extremely high velocities and the inertia of the mixture at those speeds helps overfill the cylinder.

As well they Tune the length of the runner to take advantage of pressure waves. when the valve closes it creates a wave, which will travel back up to the carb venturi, then back down the runner, if the length of the runner is the correct Lenght the pressure wave will assist in pulling more air/fuel into the cylinder, thus assisting in overfilling the cylinder.

Everything is involved, and everything has an effect. I ran into this aspect of 'fluid dynamics' while designing the exhaust system, even tried to 'splain it in a recent post on X pipes, but not that eloquently in the least!

Brian, don't know if those were your words or Ed's , don't rightly care , and I can't claim to deeply understand a half of it, but it was the overall picture I tried to keep in mind during the last iteration of the 427, and the whole basis of the 'giant pump' paradigm.

Well said 'kid'.! graemlins/thumbsup.gif

thanks for the info about overfilling. The way you stated it, it seemed as if you meant that aluminum heads couldn't achieve that, i guess you were refering to porting etc.. or that porting the head wouldn't achieve that. i guess i was confused!

Originally posted by Rapid Robert:
I've heard more than one person say that DCR is meaningless...anyone care to elaborate? =
DCR or more correctly "effective compression ratio as Dynamic implies something in motion or transition as used in Pat's DCR calculator is a very important part of the equation when it come to cylinder filing,, or lack of cylinder filling.
There is a bit more to cylinder pressure than just when the valve closed & Brian did an excellent job of explaining most of it.

Most of Brains explanation surrounds what happens around peak torque or the RPM the engines intake, cam & exhaust is tuned to.
It is why a Pro Stock engine stays in a very narrow RPM band. You cannot tune the engine over a wide band as effectively & compromises need to be made for most of the engines considered here.

At low RPM, DCR as it is being used here will suffice when trying to run crap gas with high compression.

When you start getting up near peak torque everything changes & you better damn well have fuel with enough octane to support the cylinder pressures you are making.
This is not as simple as where the intake valve closes, it now becomes what is truly Dynamic compression ratio which includes where the intake valve closes & how much cylinder filling you have done taking into account all the other factors like how efficient the intake & exhaust system is at a particular RPM, which is essentially what volumetric efficiency or VE is about.

VE is a ratio of how much you filled the cylinder verses what you could have filled the cylinder (100%) at atomspheric pressure & in a well tuned system (or forced induction) can reach well over 100%.
IE: "overfilling"

PDQ,
I think I know where you were going but your sentence:
"It also shows the relationship that static compression ratio has with respect to the intake valve closing point b/c as the intake valve closing point gets later in degrees ABDC, there is less charge trapped so in the words of the Smoke, (I think), "if you don't get much in there, you better squeeze hell outta what you do!!"
is not entirely correct.

You need to keep the intake valve open longer to fill the cylinder at higher RPM's
At lower RPM's holding the intake valve open does lower what get's "trapped" because all that nice fresh charge you just pushed in there is headed back out into the intake system.
This is not a real efficient way to lower the cylinder pressures :D


I have posted this before but just to be redundant here it is again ;)


DCR.
While I don't post it much, here are a few thoughts for you to ponder.

First let me say I think that Pat's DCR calculator is an excellent tool when used with a bit of common sense.

Here's some of my thoughts about DCR & high compression that I have posted before.

With a big cam you will see lower cranking compression but you also have to use a little common sense with the slam a big cam & lower the DCR syndrome
It may have low cylinder pressure at cranking & low rpm's but somewhere it is going to start getting efficient & the engine is going to see whatever compression you have.
If the fuel isn't good enough when this happens ugly things can & eventually will happen.

If the plan is to use & lean on your engine with pump gas most of the time I would prefer to limit the static compression with aluminum heads at 10.-10.5 for 91 octane & 10.5-11 for 93 & change the cam accordingly.

You are right in that cranking compression which is part of the DCR is determined from when the intake valve closes.
The higher the static compression the higher the cranking compression will be the sooner you close the intake valve.
This I think we all agree on.

Now there is a lot of other things that will effect cylinder pressure to a certain extent, like Barometric pressure, cam intensity, engine temp, air temp, humidity & probably a lot of other little things I missed as well.

Here's another thought to screw up the works,,
You can build an engine with say 13.0 & overcam the crap out of it & on paper the DCR will tell you it will run on 91 octane.
The problem comes when that engine gets up in the rpm & becomes efficient & starts actually seeing that 13.0. Now that DCR becomes less of an issue as you are starting to keep pressure in the cylinder & with enough load without proper fuel, it will detonate.

The load part is why lighter low gear cars will usually tolerate more compression than a heavier or higher geared car.

It also works the other way.
We do restricted engines you just could not put a load on at low rpm in most cases.
Small cam hi compression deals like 13.5+ with a cam of say 240 or so @ .050 & at low speeds they will detonate themselves to death if you ain't careful but from say 4000 up they will never see that 13.5 compression as the intake is too small to let enough air in to fill the cylinders

Is this enough confusion yet??

Anyway, you are only compressing what is in the cylinder from the time the intake valve closes & this can be completely different depending on a number of things but at cranking speed most of them are listed above I think

Anyway,,, these are just a few of my uneducated thoughts on the merits of just using when the intake valve closes to calculate DCR.

Someone else can pick up the VE, quench, swirl, chamber efficiency & timing issues :D "

I think we're gonna get there after hashing this around a couple more times!!!

And I think I read somewhere that some race engine builder has made a physically alterable intake track that does allow tuning the peak power band range over a wider amount by changing either the diameter or lengths of ports or both, but I think cubic money made the intake system!!!

Let's don't stop now!!!! I'mma reading right along and trying to learn as I go.....

pdq67

I think everyone has something to learn from this thread, no matter what your level of expertise!!
Keep it comming graemlins/thumbsup.gif

Yes,
The DCR theory is good, and the calculator is great.

It's been pretty well hashed over and I think is fairly common knowledge even if not completely understood by some.

However the 14-1 compression before aluminum becomes adventageous over iron.

I also think that aluminum will tolerate higher compression before detonation is pretty commonly known.

So I'm just after the basis for the 14-1 theory.

Jake,
I should explain my comment, The point at which Aluminum heads will make an equal amount of power with the same Iron head is where an aluminum head has a minimum of 3 points more compression.

The idea that Aluminum heads need 1 point more compression is not true, Aluminum heads will allow for more compression without detonation, true, but to be Equal in Power is with 3 points more compression.

On a typical street/strip motor with 11:1 compression, you are looking at 14:1 before the power becomes equal.

This is ONLY true if a completely fair comparison is to be made, where the cylinder heads are the same casting, worked by the same Head porter, the valve job done to the same tolerances, the angles exactly the same, the same valves, equalized combustion chamber CC's.


On the DCR comments, I'll just say this, DCR doesnt come into play when i select a cam. I selected my cam under the basis of RPM range, compression, weight of the car.

What falls under "RPM range" for me, includes the exhaust system design and characteristics, Intake, Carb, and cylinder heads (Runner volumes).

A cam, just like any other peice of the motor is a part which must be tuned to find what makes the most power in the dynamic conditions of a race track.
When tuning the cam selection, start with a small cam, and fine tune from there.

BTW, i'm glad everyone is enjoying this thread, as i enjoy it as well.

Brian,

Please tell where the 3 point spread in compression ratio numbers between aluminum and cast-iron heads info came from b/c if it's in a book, I want to read up on it.

I figure MU's ME Library over on Campus should have a copy of it..

Thanks,

pdq67

okay, I would like to see the merrits of that statment about the 3 point thing, sounds good but where is the evidence? I ask because i always look for new information but always follow the rule of don't believe it till i see it! Another thing i was curious about.. In the past i have seen Ed comment negatively about aluminum heads, (not trying to start anything here) and have seen you say that aluminum heads are overpriced and are for show only. But would it be safe to assume or would you agree that if a aluminum head will way outflows at all lift #'s than a similar Iron head, that it will make equal to more power? is it your opinion that the heat retention is more important than how the head flows and the shape of the port? I am curious because it seems the CNC'ing process and the new techonolgy in aluminum heads makes repeatedly way better flowing/designed heads than most cast iron heads for less money than a set of professionally ported iron heads.

Yes,
3 points difference to equalize the power sounds a bit steep.
If you said 1.5 points I would probably be easily convinced.

What makes it necessary for 3 full points of compression..
Obviously let's say a 10.5-1 pump gas SBC will run with iron heads. Your combo for example.
So you would need 13.5-1 and not expect detonation with aluminum...

You could get into thermal conductivity comparisons and maybe make this argument make sense, but only from a static transfer standpoint.
Under running conditions, I don't believe even the much greater conductivity of the aluminum loses the heat fast enough to make 3 full points of compression necessary to make up the power.

There was a test between ALMOST identical Motown iron and alum heads in a mag article. On the dyno the heads were almost identical power wise, with the alum actually having some slight advantage, supposedly due to a slightly smalelr comb chamber and higher comp.

Same runner shapes, valve sizes, etc..

I'm a believer in an iron head but..
wouldn't expect to need 3 points of compression to make up for lost power with alum heads.

One interesting point though..

Lets go back to a the typical 1 full point or slightly more of compression.

Using a generic SBC,
If you have a 10-1 motor, with a typical street strip cam. Use your combo again. It is similar to what I would build.
Then you went to a aluminum head that put you at 11-11.25-1.
Same cam, no other changes except combustion chamber shape/cc.

Wonder how the additional compression even with more thermal loss affects low rpm torque, idle quality, etc.
The additional static compression should make a more responsive combo with better idle quality, especially if the cam is fairly healthy.

Paul,
Its from a Racer with a background in mechanical engineering and a lifetime of experience in drag racing and specifically stock eliminator racing. Stock eliminator racers, as i've found, are some of the most technologically advanced sportsman racers.
As well another racer in which many board members are familiar with. If aluminum heads would make more power on Ed's combo....they would definetly be on there.

Books can be very helpful in understanding concepts and basics of making power, but when it comes down to it, the authors are not going to give away their most current information, and technology.

I find speaking with the engine builders, racers who've been around for awhile, is much more enlightening then reading even the most current books.

If you have the time one day, speak with Darin Morgan of Reher Morrison, he is a very good guy, and reher-morrison has for the most part an open shop policy where they will explain making N/A power to anyone who asks.

jake,
I never said when using Pump gas. Instead 3 points to make Equal power, use the correct gas.

Pump gas doenst come into the question, pump gas is only going to withstand so much compression, and i wouldnt personally push the compression too far with aluminum heads and pump gas.


That magazine comparison is Bogus, the aluminum head had CNC ported combustion chambers. I wasnt running the test, and didnt set up the heads, to be quite honest i dont believe the results....there are far too many influences on a magazine comparison to believe the test was unbiased.

When speaking of making power, the goal is to optimize cylinder pressure under dynamic conditions (not to be confused with DCR), and loosing heat (and therefore pressure) through the chamber, you're loosing power.

Out of the box cylinder heads are not equal, even of the same casting, until the valve job is done to the same tolerances, and the chamber volumes are equalized, you cannot say the heads are the same.


Cody, there is alot more to do with it then flow numbers, many characteristics of the cylinder head, with focus on the bowl, and valve seat areas. Many stock eliminator and super stock heads worked by the right person will far outperform AFR heads out of the box, and that is the nature of the beast, and the reason that you see stock eliminator cars in the 10 and 9 second ranges based on factory combinations.

Keep in mind, the Stocker heads are very close to factory runner volumes as porting is illegal in the class. Although most of the heads are not legal.

Brian,
Gotcha on the fuel selection..

Also I agree I seldomn use magazine comparisons as a "criteria" and even less seldom believe the HP numbers.
But on a back to back dyno test for a parts swap I would at least check out the numbers.

On the stock eliminator topic,
No they are NEVER legal if they are competitive, nor are they cheap...
10K for head R&D for even a small time competitive team is not unusual.
Factory castings...
Amazing what they do. Neat to know WHAT they do to the heads too ;)

Okay but are you saying that cast iron heads are going to be more consistent in tolerances than aluminum? i doubt it. I don't want to be a hard head and just argue because i bought aluminum heads but i just don't see the valid points, how can you compare super stock heads to AFR heads, and 2 i don't think that is true that their heads will outperform AFR's what merrits do you have for this? Obvioulsy flow#'s arent' everything but when you have a decent sized port and a ton of flow that IS going to mean something. And it is very hard to compare heads on a car due to so many different factors so flow numbers is almost the only thing we can compare, but you have to know how to compare them. When comparing BBC heads AFR CNC heads are flowing upwards of 375CFM, i would like to see a stock casting iron head with a factory runner volume do that! although that obviously isn't a fair comparison. I respect your opinions and i don't want to get into a war over this but it seems that there isn't a lot of proof to back up these statements. seems that you guys have more knowledge than me so i will try and listen and have open ears. BTW good point about the mag, since the latest thing is aluminum heads, of course they would want to advertise the aluminum working better!

Not more consistant in tolerances, i'm saying the factory tolerances in casting and machining are not to tight enough tolerances that a fair comparison can be made without the castings being worked by the same person TO the same tolerances in the valve job, clearances, chamber CC's, runner volumes and shape.

its simple, look at what stock eliminator racers all over the country are doing with "stock" castings, which arent far from stock runner volumes.

I'll explain more tomorrow, but for now, i'm tired.

okay sounds fair, but lets stick to things that relate to our cars. also in all honesty, do you think if those teams were suddenly allowed to start using stock degree/non raised port aluminum heads that they could CNC or whatever, would they go for it?i don't think comparing their heads to heads for our cars really is any kind of comparison, anytime people are racing for money, a lot more money goes into it! although i guess it does show what can be done with those stock castings

The mag actually "expected" some monor loss of performance but didn't see it. It was an older article.

Cody,
How is comparing AFR's and Stock racer stuff not fair...
Stock classes are running pretty good for the equip they can use, and many other racers with similar combo's aren't getting the resutls even with AFR or other "better" aftermarket stuff...
Seems pretty fair to me in respect to aftermarket stuff..

I have a friend who is a stock eliminator racer, G/SA and K/SA. Multi national record holder too.
His 403 cid Olds powered cars must use stock intakes, carbs, heads, compression, no more than a stock lift cam (~.440" IIRC) and runs mid 11's.

That is a full weight steel car with cage. Think about it...
8.5-1 comp.
403 cubes
.440 lift cam= mid 11's?

Say it was a Chevy powered car with a 400 SBC. Doing about the same.
I doubt AFR's with the same runner volume, regardless off flow numbers would pick the car up much if at all.

But I know what kind of work gets done to the heads and being a machinist and having a decent understanding of the valve angles, seats, etc.. Brian is speaking of..
Although stock class racers must use stock valve angles.. ;)
LOL

Regarding the 3pt rule:

I'll stick within the narrow application that I'm fairly familiar with, which is sbc. A 406-421 sbc with 13.5:1 compression, ported alum 23dg heads that flow in the 310 range@650 lift, and the requisite roller in the 260-270 range and ~.675 lift will make between 650hp-700hp depending on the ring package and whether or not the owner is using a vacumn pump. Most of these cars with this "typical" bracket type small block will run somewhere between 132-134 in good air in a 3400lb car. I see cars like this at HRP often.

Now, if I understand this "3pt rule" correctly as its been explained (keep in mind I'm very capable of misunderstanding graemlins/clonk.gif ) I should be seeing some 10.5:1 406-421sbc running iron heads done with similar head work to yield similar airflow characteristics (notice I didn't just say similar flow #'s) with a matching cam (correct for compression and vehicle weight) running similar #'s at the track and be able to do it on pump gas where as the 13.5 alum head motor WILL need race gas. There are some decent iron castings (in the 23dg market) that WILL produce comparable airflow quantity and quality compared to their aluminum counter-parts, so it really should'nt be hard to find a car running this type combo and the above mentioned #'s. BUT, I have yet to see ANY combo of this sort run those #'s.

The potential power difference between 10:1 and 13:1 in a motor of this type is approx 50-60hp which is a fairly large amount and franly I'm just not seeing iron headed 10:1 small blocks making the same power as alum headed 13:1 small blocks.

Brian, here's something for you to consider, while this is obviously not an apples to apples comparison it is pretty close. Greg's (aka Kazuaki) EC runs a similarly built 383 as yours. He runs a Comp solid flat cam with similar specs to yours with UNPORTED 170cc edelbrock alum heads and 11:1 compression and his car runs very similar #'s to yours. The last I remember he ran in the 11.30's@117 after removing some weight to get the car down to 3300lbs. Now, going by this 3pt rule he'd have to be running upwards of 13.5:1 to be running in the same ball park as yours.

I hope this doesn't come across as argumentative, I'm simply stating what I've seen and what occurs to me with respect to the above mentioned comparison. I do recognize that ALL things being equal iron will make more power but I have a hard time believing its 3pts (50-60hp) better, 1 pt (15hp) I can believe and seems to line up better with what I've seen personally.

Regards,

John.

well i don't think comparing the 2 is fair because you will never get one of those cars to ever have a set of aluminum heads on it because it is against the rules. also AFR makes excellent small block heads but i am more familiar wiht the BBC heads, and of course they are not the BEst of the best, just the best out of the box. they are teh cats meow in terms of out of the box, but of course in a real race world they are many other alternatives. I was just using them as an example. Does anyone have any facts on #'s or pics of what the stock class BBC heads look or perform? Also i believe the chassis and driver in those cars has a LOT to do with the timeslips they are getting, not to rule out then power of the engine, but it seems we are talking about all out power here.

Originally posted by Motor Martyr:
Paul,
Its from a Racer with a background in mechanical engineering and a lifetime of experience in drag racing and specifically stock eliminator racing. Stock eliminator racers, as i've found, are some of the most technologically advanced sportsman racers.
As well another racer in which many board members are familiar with. If aluminum heads would make more power on Ed's combo....they would definetly be on there.

Books can be very helpful in understanding concepts and basics of making power, but when it comes down to it, the authors are not going to give away their most current information, and technology.

I find speaking with the engine builders, racers who've been around for awhile, is much more enlightening then reading even the most current books.

If you have the time one day, speak with Darin Morgan of Reher Morrison, he is a very good guy, and reher-morrison has for the most part an open shop policy where they will explain making N/A power to anyone who asks. =
Brian,
On this I am going to have to respectfully completely disagree with your sources.

There is absolutely no basis in fact for a 3 point spread in power differences between two materials.

There is some truth in that aluminum will dissipate heat faster than cast iron & heat is power but under dynamic conditions of cylinder filling, emptying & especially the amount of time that this heat difference is making power which is less than one fourth of the cycles in a four stroke engine there is just no way there will be any where near this kind of difference.

This is not just my opinion it is fact.
I have had the privilege of knowing some of the best porters,head designers, engine designers & builders around & there is not one I know of that will agree with this concept including Reher Morrison.

One of the very first thing RM will tell you is if you can afford it buy aluminum heads. This is almost a direct quote from them.

Some of the most sophisticated V8 engines as we know them are in NASCAR & they certainly have the capability of using cast iron & making them exactly the same as an aluminum counterpart if what you are saying is true.
Yet even in the 9.0 & intake restricted engines they do not.

I could go on but suffice it to say I believe you will find the consensus of opinions from almost all of the top engine guys in the country will be that an aluminum head is a far better choice for a serious performance engine unless there are rules constraining the head you can use.

But just because there are rules & folks can & do make outstanding power under these rules this in no way means they wouldn't or couldn't make as much or more power with a head of the same design in a different material ;)

And if you gave them a better designed head they would certainly make a lot more power.

I just wish that someone with the cash (so that leaves me out redface.gif ) would step up to the plate and have a set of iron heads and a set of aluminum heads worked to exact standards. Those exact specs should include:

valve size
chamber size
runner size
port job
valve job
bowl work

Etc., Etc. Probably more I can't even think of. Just let a competent head guru breath identically on the castings and let 'er rip.

I honestly think that's the only way that this debate will be settled. I for one am eagerly anticipating the results. redface.gif

There are a couple of other things in aluminums favor Wolfy, As the motor gets hotter with an aluminum head it will generally make more power than it did cold. We saw this on a Dynojet session. The second pull has always resulted in 5-6 more horsepower than the first. I bet that Ed's car would be faster with a set of oval port Brodix BB Race Rite Ovals in place of his iron G.M. ovals. When we went to a 335 CNC Dart in place of the pocket ported 320 iron chevy square port chevy castings we picked up about 3 1/2 tenths and four MPH trap speed with 1/2 point increase in compression.

Motor Martyr, (this is off the subject but) I can't seem to find Ed Bigley's car and info. anymore at Prestage, what gives? I figured you are a customer and friend of his so i just thought i'd ask. Isn't that red '68 Chevelle, in your pictures, Ed's car? If he's gone from the board that's too bad.

Brian,

Very good discussion, but I believe your source may be lacking facts or is stirring the pot through you. No offense to you Brian. You have been a "model citizen" since you have come back to this board.

To quote Ed (racer1320)....

http://drr.infopop.cc/eve/ubb.x?q=Y&a=tpc&s=3476075&f=80760912&m=340108774&p=1



TC's performance forum (oxymoron) is for those that don't race, wear their desk top dyno numbers like a badge of honor, judge their performance by the seat of their pants and quote magazine articles while they ponder with reverence every word David Vizard has ever written!!!

It's the place where myth, rumor and hearsay is perpetucated and embraced! Sounds like Ed is doing the perpetuating of rumor, myth, and hearsay. It kills me how Ed can say how all test data is bogus unless HE does it with A-B-A testing and a control car in the other lane, but yet can say that aluminum heads need 3 points of additional compression to make the same power as cast iron with nothing to back it up??

Has he done the testing? Where are the numbers that back this story? ....and remember, dynos and flow benches are useless devices. Let see some track times WITH incrementals. I'm betting they don't exist.

I know this post will likely lead to receiving nastygrams full of personal attacks, but so be it. That in itself is funny. Ed says he basically despises this board and all of those on it, yet he seems to be up to date on every post. ;)

Wolfplace,
I think one of the main reasons Nascar uses Aluminum heads is the weight factor in regards to the fact the savings in weight can be shifted to the most beneficial place in the chassis.
Jeff Gordon was fined for having an Magnesium manifold at one point.

Originally posted by DragRacer:
Brian,

Very good discussion, but I believe your source may be lacking facts or is stirring the pot through you. No offense to you Brian. You have been a "model citizen" since you have come back to this board.

To quote Ed (racer1320)....

http://drr.infopop.cc/eve/ubb.x?q=Y&a=tpc&s=3476075&f=80760912&m=340108774&p=1

</font><blockquote>quote:</font><hr />

TC's performance forum (oxymoron) is for those that don't race, wear their desk top dyno numbers like a badge of honor, judge their performance by the seat of their pants and quote magazine articles while they ponder with reverence every word David Vizard has ever written!!!

It's the place where myth, rumor and hearsay is perpetucated and embraced! Sounds like Ed is doing the perpetuating of rumor, myth, and hearsay. It kills me how Ed can say how all test data is bogus unless HE does it with A-B-A testing and a control car in the other lane, but yet can say that aluminum heads need 3 points of additional compression to make the same power as cast iron with nothing to back it up??

Has he done the testing? Where are the numbers that back this story? ....and remember, dynos and flow benches are useless devices. Let see some track times WITH incrementals. I'm betting they don't exist.

I know this post will likely lead to receiving nastygrams full of personal attacks, but so be it. That in itself is funny. Ed says he basically despises this board and all of those on it, yet he seems to be up to date on every post. ;) </font>[/QUOTE]Jason is dead on with an "0". graemlins/thumbsup.gif

Funny how Ed made those remarks on DRR, yet still finds the need to lurk here and e-mail folks making corrections like when he contacted Mike Fuedo. Hi Eddy graemlins/waving.gif .

I only recently realized how Ed likes to claim Dominators would be slower on a footbrake car, but he's never personally run one on his car. he also likes to claim that rectangular port heads would be slower, but again, has never run them to prove his point either way.

he also claims aluminum heads would be slower as well, and again, he's never made comparison runs on his own ride.

How can a person make performance claims about a specific chassis type, weight, etc, yet has never made A-B-A comparisons to prove those comments true or not. Sounds like Ed is eating his own words as he is doing just as he claims all here on TC do (perpetuating myth, rumor and heresay) :rolleyes: .

I also thought his comment to Gatewayracer was quite comical about Gateway posting pics of his two wins this seaon (showed a picture of win decals). He claimed Gateway was not a bracket racer rather one only wanting to show off his accomplishments or race for trophies to brag about...funny thing is Ed likes to bring up his "wally" at any time it suits his agenda or to stick out his chest and boast...Jason, maybe one could dig up the direct quote on this subject as I can't remember which thread Ed made these comments to Gateway.

Brian, you sound like a good young fellow. Your pretty smart and unlike Ed, your good with your hands and CAN build a car and assemble and engine yourself. I would only suggest you limit your exposure to him and take what he says with a grain of salt. Your young and quite impressionable and you need to learn to think for yourself and not regurgitate what Eddy tells you. If I were you, I'd spend more time listening to your father (he was a racer, wasn't he?) and less time with Ed. His ego and arrogance will only drag you down to his level. I truly believe your better than that.

With moving recently, I haven't spent near as much time on the net as I used to. Good thing as my latest dealings with Ed made me realize how "soap opera like" the net can be and how there's so many more important things in life here that I can spend my time on/with.

John,
its not a good comparison, and Greg's best ET is an 11.39@ 117mph

My best is 11.60 at 117.31 MPH, going on MPH (MPH Is HP) in a similar weight car, Mine is making more HP.

I hope this doesnt insult Greg, as it is Not meant to be an insult. Greg has done an Excellent job with his combo!

Greg has 11.2:1 compression, i have 9.8:1 compression, and to be completely fair the heads are Entirely different between what we both have.

In all fairness to my combo, i have 21 passes on the car, and its FAR from optimized, having no traction device as of yet, No tuning done, aside from the timing Guess, and the Carb swap.

A much better comparison would be to find a car that can match or beat the BSE small block, 3100lb car with a 355" Motor with 10:1 compression, Iron 180cc Dart II cylinder heads with nothing but bowl work and good valve job done, 700 double pumper, Solid cam 244/252 dur. .050", 106LSA, 1-3/4" headers, Powerglide, and 10" converter, with 4.56 rear gears.

The BSE small block is much closer to Optimized then my combo.

I still have plenty of tricks up my sleeve, rather then Jump to conclusions now, just wait until i get into the testing and tuning phase on my combo. Right now, aside from the two changes i made, what i'm trying to accomplish is consistancy, when the car is consistant i will begin tuning.

Mike,
I think RM is one of the best places to buy a motor, but with respect to RM, they're telling you to buy Aluminum heads for different reasons.
Reher morrison isnt attempting to optimize a low compression Pump gas motor, ethier.

The advantage to aluminum heads as they see it, is that you can buy anything in aluminum, and you dont have to work with "low tech" castings. On an all out racecar, turning sometimes upwards of 8500-9000+ rpms, its Smarter to start with an Aluminum casting that can be easily manipulated to what they want to see.

Aluminum heads in a race car application are not a bad thing, as they can be easily repaired, easily manipulated and they are light.

But keep in mind, You, me and the rest do Not know what the Reher Morrison team, or any team in that respect (a prostock team) are doing to the chambers of these heads to retain the heat.

I can tell you that the Late Model Porsche cylinder heads have a Ceramic coating in the exhaust port to retain heat/Velocity otherwise lost with the aluminum heads

I highly doubt that the Top motorsports teams in Nascar, NHRA/IHRA drag racing, Indy car, ect are Ignoring the fact that they are loosing power out of the chamber via. heat transfer to take the weight advantage.

My idea is that they're taking advantage of both :D

Of course they want you to buy Aluminum cylinder heads, they are a business, and they know what the majority of customers want to hear.
As well, they are selling aluminum and only aluminum cylinder heads ;)


If you guys are Up for it, supply me with Two Identical pairs of Iron and aluminum cylinder head BARE castings. As well supply the guides, valves, springs, retainers, studs, ect.

I will set the valve angles and seats to the same dimensions. I well set the chambers to the same CC, i will have the ports worked by the same hand, on the same day, after the same amount of drinks :D ;)
I will put the same guides in the heads, same valves, same back cuts on the valves, same seat widths. Same springs, same installed heights, same spring seat and open pressures, same rocker arms.

I'll even return them afterwards to the supplier for "inspection" with a small tolerance.

After the car is consistant, i will Make the comparison on my car.

I'm as intrigued and interested as anyone reading.

Hot Dang, look what I started, LOL.

I'm having a lot of fun reading all of this. As you all know, I'm as Rookie as a Rookie gets, and my brain is like a sponge, soaking up everything I get near. I like this discussion. Hopefully Brian can make a A-B-A test with his car someday, I want to know the "end all" answer to Al vs. Fe.

As some of you may know, a 383 combo is slowly being imagined in my own brain. At this point, I think I may just build a nice 383 rotating assembly and match the valve train to my drive train and just bolt on my 882s on top of it all until I can make a decision between AFR195 and Dart IE180 heads. As of now, Dart is pulling way ahead just from a $$$ point of view. :D

GREAT discussion guys. graemlins/thumbsup.gif

Todd,

I stand behind my friend Ed, he's a good person, and a great friend.

Ed's ideas as based on fact and testing, weather it be His car, or a fellow racers car. Where i race, the group of racers that i've be invited into are all very smart, and all have done there own testing.
Everyone in our group of fellow racers brings a wealth of knowledge to the table.
This includes a host of stock eliminator racers, top bracket racers, heads up class racers, top engine builders, and others who enjoy bracket racing.

Just because you disagree with him, doesnt mean he is a bad person.

Dominators are slower on a footbrake car, My friend Rob Richter had a 69' Camaro Race car, Small block chevy powered and turning LOW 10's, putting the car on the bumper on some passes.

He used to use a Dominator to kill the launch on HOT days when the track wouldnt hold.

Rob is an excellent racer and was Often invited to do testing when ATI would rent tracks strictly for stock eliminator converter testing.

My dad is a fabricator, i have him to thank for my ability to fabricate and weld, but he was never a racer.

keep in mind, my advice here relates to the typical street/stripo ride, not a Full Out race motor.

A full out competiton motor, is a much different beast, and what does apply, and what doesnt apply to a street/strip motor must be looked to with a grain of salt.

Wow!! this is amazing! even with a couple of near attacks on Ed, this thread remains civil and with great info! I think this is a first ever! The earth must of reversed rotation! lets keep it up.

Originally posted by Motor Martyr:
Todd,

I stand behind my friend Ed, he's a good person, and a great friend.

Ed's ideas as based on fact and testing, weather it be His car, or a fellow racers car. Where i race, the group of racers that i've be invited into are all very smart, and all have done there own testing.
Everyone in our group of fellow racers brings a wealth of knowledge to the table.
This includes a host of stock eliminator racers, top bracket racers, heads up class racers, top engine builders, and others who enjoy bracket racing.

Just because you disagree with him, doesnt mean he is a bad person.

Dominators are slower on a footbrake car, My friend Rob Richter had a 69' Camaro Race car, Small block chevy powered and turning LOW 10's, putting the car on the bumper on some passes.

He used to use a Dominator to kill the launch on HOT days when the track wouldnt hold.

Rob is an excellent racer and was Often invited to do testing when ATI would rent tracks strictly for stock eliminator converter testing.

My dad is a fabricator, i have him to thank for my ability to fabricate and weld, but he was never a racer. Brian, I was merely pointing out that I don't believe anyone should make performance claims about equipment they have not personally tested on their own car. If you claim someone elses testing, then that is the same as giving second hand info and is suspect IMO. I was not trying to state any personal opinions on dominators, aluminum heads, or even rectangular port heads. I've run two of the three and know which works and which didn't with my own setup.

For the most part, I believe Ed's advice is pretty solid. My own cars performance shows his advice does work.

BUT, when Ed can't stand that a "friend" could possibly disagree with him, or even point out that he dropped the ball on a converter test, then he goes ballistic and stoops to making personal attacks. When someone makes negative comments on myself, my wife, my children, or our income or how much money one has or doesn't...even what type of job one may have or where they live or type of home, that is crossing the line. The internet is a great place to share or even debate topics and ideas. When a person resorts to making personal attacks, that is unacceptable IMO and shouldn't be tolerated in any forum.

Such occurances have led me to spend more time with my family and less with this electronic (internet) family of sorts.

I wish you continued luck with your cars performance and tweaking. I will also try from time to time to stop by and keep tabs on how your doing with the tweaking.

Hope this thread continues in a positive manner.

Originally posted by Motor Martyr:
John,
its not a good comparison, and Greg's best ET is an 11.39@ 117mph

My best is 11.60 at 117.31 MPH, going on MPH (MPH Is HP) in a similar weight car, Mine is making more HP.

I hope this doesnt insult Greg, as it is Not meant to be an insult. Greg has done an Excellent job with his combo!

Greg has 11.2:1 compression, i have 9.8:1 compression, and to be completely fair the heads are Entirely different between what we both have.

In all fairness to my combo, i have 21 passes on the car, and its FAR from optimized, having no traction device as of yet, No tuning done, aside from the timing Guess, and the Carb swap.

A much better comparison would be to find a car that can match or beat the BSE small block, 3100lb car with a 355" Motor with 10:1 compression, Iron 180cc Dart II cylinder heads with nothing but bowl work and good valve job done, 700 double pumper, Solid cam 244/252 dur. .050", 106LSA, 1-3/4" headers, Powerglide, and 10" converter, with 4.56 rear gears.

The BSE small block is much closer to Optimized then my combo.

I still have plenty of tricks up my sleeve, rather then Jump to conclusions now, just wait until i get into the testing and tuning phase on my combo. Right now, aside from the two changes i made, what i'm trying to accomplish is consistancy, when the car is consistant i will begin tuning.

Mike,
I think RM is one of the best places to buy a motor, but with respect to RM, they're telling you to buy Aluminum heads for different reasons then overall power gains.

The advantage to aluminum heads as they see it, is that you can buy anything in aluminum, and you dont have to work with "low tech" castings. On an all out racecar, turning sometimes upwards of 8500-9000+ rpms, its Smarter to start with an Aluminum casting that can be easily manipulated to what they want to see.

Aluminum heads in a race car application are not a bad thing, as they can be easily repaired, easily manipulated and they are light.

But keep in mind, You, me and the rest do Not know what the Reher Morrison team, or any team in that respect (a prostock team) are doing to the chambers of these heads to retain the heat.

I can tell you that the Late Model Porsche cylinder heads have a Ceramic coating in the exhaust port to retain heat/Velocity otherwise lost with the aluminum heads

I highly doubt that the Top motorsports teams in Nascar, NHRA/IHRA drag racing, Indy car, ect are Ignoring the fact that they are loosing power out of the chamber via. heat transfer to take the weight advantage.

My idea is that they're taking advantage of both :D

Of course they want you to buy Aluminum cylinder heads, they are a business, and they know what the majority of customers want to hear.
As well, they are selling aluminum and only aluminum cylinder heads ;)


If you guys are Up for it, supply me with Two Identical pairs of Iron and aluminum cylinder head BARE castings. As well supply the guides, valves, springs, retainers, studs, ect.

I will set the valve angles and seats to the same dimensions. I well set the chambers to the same CC, i will have the ports worked by the same hand, on the same day, after the same amount of drinks :D ;)
I will put the same guides in the heads, same valves, same back cuts on the valves, same seat widths. Same springs, same installed heights, same spring seat and open pressures, same rocker arms.

I'll even return them afterwards to the supplier for "inspection" with a small tolerance.

After the car is consistant, i will Make the comparison on my car.

I'm as intrigued and interested as anyone reading. ======
I see we are all still here this morning :D

First let me address the comment by 1968 hot rod
of why NASCAR uses aluminum heads.

I am well aware of the weight aspect & agree but if in fact they could make the same or more HP with 3 points less compression which is in reality a mechanical impossibility they would be using cast heads regardless of the weight penalty.
In a 9 to 1 engine a 3 point compression difference is on the order of 5 to 10% depending on who you want to believe but even using the conservitive 5% in a 600+ hp engine in the competitive world of NASCAR where 1 HP is big this is a huge advantage.
In your spare time look up & study a little thing called "Otto Cycle Efficiency". ;)

Brian,
While I agree RM is at the top of the game I do not buy engines from anyone & I am not arguing the fact that on a lower compression engine a cast head should make more power than an aluminum head in theory.
The exhaust gas velocity argument does not hold water.
You are referring to about 2" of the total exhaust tract at the point of maximum velocity so once the head is close to temperature I think this becomes a mute point.
Coatings can & do help power output but only to a small extent.
Anything you can do to keep controlled heat in the chamber during combustion is going to help slightly with power.
This is a fact I don't think will be argued by anyone.
I am also well aware that companies sell aluminum heads have this as part of the agenda but the facts remain that an aluminum head is not going to give up the potential power of 3 points of compression to a cast head.
Another point brought up by Harold is also a fact.
The very fact that aluminum dissipates heat as well as it does will let you run an engine closer to the edge without destruction because the heat factor is more controllable.
This again is a mute point as in drag racing in particular you are not running the engine long enough for this to be a factor unless of course you run it into detonation.
And again, the only time heat is making power is on the power stroke, the rest of the time it is your enemy except in the exhaust system where it helps with velocity.

On this subject of aluminum vs cast, I guess we are going to have to "agree to disagree" as the facts as I see them just don't support your position of a 3 point spread in compression.

Also, the closest you are going to come to a back to back test is probably with Dart heads as they are a reasonably close platform to start with & I personally feel that it would be a push in power output but even here the test essentially means nothing as you are using a pretty mild compression test bed & only one combination & I think you will agree that the combination of parts is everything for an end result.

Another fact is there has been way more advances in the design of cylinder heads in aluminum than cast iron so again for anyone that can afford to step up to a high quality head without rules constraints of course, the power potential is going to be greater with the aluminum.

Also, as long as someone had to bring Ed into this discussion for whatever reason??,,, I do not know Ed, I don't care who he has p!!sed off, his accomplishments speak for themselves as do yours which I can only assume are a direct result of your association with him.

I neither dislike or like the man as I haven't had the opportunity to speak with him but I do admire his tenacity & accomplishments with the combination of parts he has selected & what he has done with them.
I don't agree it is the only way to do things but that is my prerogative.
So I refuse to get into the "Ed bashing deal"

While I don't agree with this particular opinion on heads be it yours or someone else's I still feel Mr. Ed has helped you immensely as your combination has evolved into an enviable one in a very short time,,,, just don't get into the "it's the only way" syndrome ;)
someone may always come up with a better "mousetrap" (no Pun intended)

Aluminum is much easier to work with,make castings,porting,its easier to repair and cheaper...I see that as an advantage aluminum. Its hard to compare Nascar and drag racing as far as which head to choose, two different animals. Seems the weight savings would lean more towards drag racing, ever latch onto a iron big block chevy or hemi head?

I have 9.6:1 compression, 9.3-9.4 with Brians formula. So... if I put some iron heads on my car, equal to or better than my Edel RPM's, and use 6.6:1 I'll still hit 12.0's? How about 7.6:1? I don't think so.

I can run 87 octane when the outside temp is 110+ and engine temp is 215 with my A/C blasting. This was a big reason why I went with alum heads on this engine. Am I giving up ET? Maybe, but not much. IMO

How much ET is an electric waterpump worth over belt driven?

Originally posted by Motor Martyr:
John,
its not a good comparison, and Greg's best ET is an 11.39@ 117mph

My best is 11.60 at 117.31 MPH, going on MPH (MPH Is HP) in a similar weight car, Mine is making more HP.

I hope this doesnt insult Greg, as it is Not meant to be an insult. Greg has done an Excellent job with his combo!

Greg has 11.2:1 compression, i have 9.8:1 compression, and to be completely fair the heads are Entirely different between what we both have.

In all fairness to my combo, i have 21 passes on the car, and its FAR from optimized, having no traction device as of yet, No tuning done, aside from the timing Guess, and the Carb swap.

A much better comparison would be to find a car that can match or beat the BSE small block, 3100lb car with a 355" Motor with 10:1 compression, Iron 180cc Dart II cylinder heads with nothing but bowl work and good valve job done, 700 double pumper, Solid cam 244/252 dur. .050", 106LSA, 1-3/4" headers, Powerglide, and 10" converter, with 4.56 rear gears.
Brian, your correct, its not a fair comparison. Gregs heads, while not "completely" different (since we are talking about standard runner 23dg heads with standard valve locations and there's only so many ways to dice an onion), are MUCH smaller than yours but still manage similar performance despite only having 1.4pts more compression and not the required 3pts. Now, to go any further with the comparison would be splitting hairs since we (or atleast I) don't know the weather conditions of Greg's pass.

As far as the "BSE" camaro. The concept of the "BSE" combo is not whats in question here, its the claim of the 3pts handicap for alum heads all else being equal and I'm sure the owner of the car would not attribute all of its performance to the material of the cylinder head. But, the next time I'm at the track I will make an effort to locate a 13:1 355 running a flat tappet cam and notice its performance.

Also, one of the reasons for the stellar performance of your friends cars is the air you have the priviledge of running in. By no means am I saying its the only reason, but it sure don't hurt. Here in Houston we do get some decent air in the fall/winter but not like yours.

BTW, your doing a great job with your car and its performance and I'm sure we'll be reading about more new bests as you find traction and weather. graemlins/thumbsup.gif

Originally posted by Rapid Robert:
Aluminum is much easier to work with,make castings,porting,its easier to repair and cheaper...I see that as an advantage aluminum. Its hard to compare Nascar and drag racing as far as which head to choose, two different animals. Seems the weight savings would lean more towards drag racing, ever latch onto a iron big block chevy or hemi head? Hmmm,,

Actually, yes I have had the occasion to be around a number of Hemi's & Rats :D
Both drove & worked on a number of 354's & 392's in AFD for years & the Hemi's were cast iron, huge & very heavy.
Just got done building a very cool blown 392 for a street rod that there is a pic of on my site.

Why exactly are the heads "two different animals"?
The biggest difference is you need to be a little more conservative with an engine that has to hopefully last a bit longer than 10 seconds at a time & you have more of a "drivability" issue.
When it comes to heads they are quite similar except for the fact in road racing & circle track you need to be a lot more aware of issues at less than wide open throttle,, kind of like a street strip deal only normally a lot more expensive :D
You can err on the large size in a drag race deal & it will be more forgiving than with a car that needs "drivability"
The last sentence is not an endorsement for sewer pipe intake tracts. ;)

A certain size engine regardless of venue will perform the best with the smallest port that will flow enough air to make the power intended consistent with the RPM you intend to run the engine to.
Or,, it takes an "X" size port to fill an "X"
size cylinder effeciently to "X" RPM.

And both venues are looking for the most reliable HP they can make consistent with reliablity except in the case of bracket or limited ET type racing where the end HP is not really an issue, consistency is ;)

Mike,
I think my car would be an excellent test bed after i'm finished sorting it out and getting it consistant.

I'm already planning a project of my own in which i'm going to be testing a frame that i'm fabricating for the Street/Strip all out performance application.

While this is of course a much different scenario, the point still stands that any testing done on this car would be effective.

The "lack" of compression makes the difference between iron and aluminum that much more pronounced.
Afterall when dealing with low compression, a little is a lot, in which a small increase means more power then in a motor with a lot of compression.

Same scenario with cylinder pressure.

The porsche example is my way of thinking that if they can make a ceramic coating for an exhaust port, then they can ceramic coat a combustion chamber.

BTW, i wasnt suggesting that you buy your motors, i know you do your own work, i was simply stating that RM is an excellent shop.

John,
the air we race in, is in no means better then the air you guys race in.

Yesterday the humidity was very high, the DA was over 3000' and the temperature was in the 90's.

At Atco when i made the 11.60 pass, the DA was 1500'-2000' over the span of the day.

Thanks for the compliment! I'll keep you updated.

Our optimal conditions in the fall, would be similar to the conditions you guys race in, in the winter.

When making the head comparison, you have to split hairs, especially when a fresh valve job can account for 1 tenth, not to mention changing the seat angles, seat widths, the angle of the back cut on the valve, how many angles of the valve job.
The shape of the guide, the shape of the valve, the shape of th bowl, the short turn, ect.
there are alot of variables to say the least.

Especially when comparing two different cars.


Lonnie,
the Belt drive is worth ET simply because i can stage the car cooler and more consistantly cooler at that.

Brian,
Sure gald I can watch TV while doing this on my day off :D
Guess I'm "multi-tasking" :rolleyes:


I knew what you meant with the RM engine deal ;)

Actually I have a customer that races SCCA with an 18 deg 332" SB & his pistons, chambers & exhaust ports have been coated at different times.
The biggest difference was in engine temps, especially oil & piston reliability not power.
Or at least that is the way it shook out on the dyno.
The engine has made within about 10 corrected HP of the same numbers both coated & uncoated after playing with jetting, timing etc.
The coated numbers appeared to be the better.

The last iteration has made the best power with coated pistons only but is not really a fair comparison as a lot of other things were changed like the size of the cam core, pushrod type & diameter, rocker ratio, ( 1.8/1.7) & slightly different exhaust seat dimensions because of an exhaust valve reliability issue.
Essentially a new combo.

BTW, this last engine is now all aluminum & still managed to make more power & is faster on the track.

And I will agree your car would be a very good test but I still feel it would be a push in regards to power ;)

I have stayed out of this because I have been in too many alum. vrs iron wars. I did about as close a comparison as you could. In the old wagon we ran a true 11to1 468 (12 1/2 pistons milled to lower the compression) with a set of stock 392 heads (67 closed chamber alum) I knocked one the guides loose in the casting (common problem with early heads) I couldn't get the head fixed in time so I had a set of 840s (iron closed BP) done to the same specs and ran those. The car was a very consistent tenth and one half slower. Most of that can be attributed to the 80 lbs more weight but it definately didn't run any better with the iron heads. The one thing that you must remember especially on a Big Block is just the weight savings is usually good for almost a tenth.

Kudos to Brian for a well thought out and strong running combo. There is a lot going on with Brian's car, like the custom headers designed specifically for his combo, that more people should pay attention to. Kinda like the F.A.S.T. cars that run so quick yet look so stock - details, details - there is e.t. and mph in all the details. For sure he will run quicker and faster as he experiments with his combo and starts making more changes.

I love these great debates; al vs fe, oval vs ???, etc. No matter which side of the aisle your beliefs lie, the one big "detail" that has only briefly been touched on is money. Someone mentioned stock class racers with $10,000 cast iron "factory" cylinder head programs. Well of course you are going to get great results when you put that kind of money into the mix. Castings always vary, and if you were to buy up any number of al or fe cast heads from any given manufacturer you would definitely find some that made more power than others. Even Mr Bigley's results were predicated on money spent, and a fine job he has done with the $40,000+ outlay of trial and testing until reaching his current state of performance. Some may say that they could go faster with less money spent, but that would totally miss the point of what Ed was trying (very successfully) to prove about combo setup for a n/a drag only heavy middleweight Chevelle.

Thomas

Very nice job Brian... You should be proud of your accomplishment.. Ill be lucky to crack off a 11.99 with my barge.. We will see soon though.
Now get that sucker consistant and start tree'ing some of your mentors ;) :D ..

Hi Brian, In the first year when my son started racing his 3600 lb. '70 Chevelle we got down to 11.01 @ 121.5 MPH with an Edelbrock single plane and a 850 double pumper carb. It just got stuck at 11.0s and wouldn't go any quicker. We changed over to another Edel. single plane and a Dominator (model 9375) went to Noble, Ok. and the car ran 10.84, 10.76 and an on the brakes 10.86 in the same air as our local track, dispelling the mith that the smaller carb. is quicker. All the speeds were around 124 MPH with the Dominator carb. and manifold combination. The Biger carb does load up and kill the plugs, but is faster. This car has always been footbraked and before we took the 482 out, with the addition of some good "335 CNC" Dart heads and 180 foot D.A. air it ran 9.98 @ 133.7 MPH. Another day it ran three 10.0s at 134.8 MPH. (small tail wind). Most 60's are around 1.40-1.42.

OK, let's get to it!!

Should I ask the Moderators on both TC Boards if it is OK for Ed to come back aboard??

I for one miss Ed and Iman, but I don't miss the personal attacks!!

What do all you think?? As Bob Dylan once sang, "the times, they are a-changing"...

No skin off my nose, yes or no.. Just say so...

pdq67

Hi again Brian, While aluminum is probably easier to cast and machine is is more expensive than cast iron, just look at the casting prices! Probably the closest you could get to actually getting two exact duplicate castings, at least in big block Chevies, are the Dart iron eagle and the standard (non cnc ported) Dart pro-1s. I'd still like to know about Ed and his car (see earlier posts).

why should we let him back? and what makes you think the personal attacks will stop? i say let him go through Brian, it seems Brian will keep the posts civil. Brian i have to ask you, if you do, do this comparison would you be biased? or if the aluminum's worked better would you be willing to admit you were wrong?

Hey Brian,

I'm going to back-track a bit and discuss your combo a little.

I'm really interested in 377-388 stroker combos, and yours is a very interesting one indeed. You may have seen an earlier post I made about my first thoughts on a possible 383 combo. ( http://www.chevelles.com/cgi-bin/forum/ultimatebb.cgi/topic/4/20999.html? ).

As you can see, I would be starting off with semi-similar heads (minus the valve job, but I may add a good valve job. $$-pending) and a similar bottom end (I'm now thinking of forged Wiseco pistons) and that's about where the similarities end. The thing I was wondering was you quench distance, I can't seem to get you 9.8:1 figure with those pistons unless I add about 2cc's to the heads, which is reasonable. Did your valve job add that much or did they come out of the box somewhat bigger than 72cc?

Thanks again, your combo is helping me decide what I should add to mine to make it better.

Iron vs aluminum is like many other debates that have been gone through over and over before . . .

If one material was so clearly better than the other there would be no debate.

3 points more compression required for aluminum heads to run with iron is total hogwash.

The only apples to apples comparison that I've seen done was by one of the mags a couple years ago with World SBC castings. The only difference between the two heads was that the aluminum heads had CNC chambers. Probably worth a couple HP. On the dyno the aluminum heads actually beat the iron by a couple HP and that was without changing compression ratio. On the track the weight savings would have helped a little more.

I personally do not believe that there is any significant difference between the two as long as compression ratio is optimized for both types of heads. And optimizing compression for aluminum heads means adding .5 to 1 point . . . NOT 3 ;)

. . . and my sig is old -- best ET is 11.31 @ 121.8 MPH (with a single plane and ALUMINUM HEADS) ;) We'll see what new tires do for my 60' times in the next couple weeks. :D

Slowpoke,
my deck height was .004", the pistons were 6cc valve reliefs and the chambers were 72.5cc on the one i measured. The gasket was .041"
depending on the calculator, you get anywheres from 9.8 - 10.02:1.

Even so, if tested you'll find that the calculators come up high.

On the aluminum head debate. I would absolutely do to the best of my abilities a fair comparison. Why lie about it? If it makes the car faster, it makes the car faster, period.

Thanks Brian. Alright, that makes sense then. I was just wondering which gasket you were using.

Mike(Wolfplace), if you're seeing this still, what would it take to make a Wiseco 4.6cc FT measure 5-6cc? Also, maybe you can shoot me an email with some forged stroker piston prices? Or better yet, some prices for a Scat rotating assembly (9000 w/ capscrew 6"rods} with forged slugs.

Originally posted by Motor Martyr:
Slowpoke,
my deck height was .004", the pistons were 6cc valve reliefs and the chambers were 72.5cc on the one i measured. The gasket was .041"
depending on the calculator, you get anywheres from 9.8 - 10.02:1.

Even so, if tested you'll find that the calculators come up high. =
Not mine :D I have checked it numerous times against measured combos & it is always been within a couple of tenths.
On your deal I come up with 9.80 with a 4.200 gasket & 9.81 with a 4.166

Enrique,
More than it is worth for 1cc unless you are building a combination that is compression specific or were in the 14-15 to 1 area where 1cc becomes more important ;)
Even the 9 to 1 spec engines have a small "fudge factor"

Consider that you have to cut about .006" off of a head to remove 1cc from the chamber & you can appreciate how small 1cc is ;)

==========EDIT==============
Before I get flamed for being so "inaccurate" please also consider that 1cc on most 10.0 (give or take) engines is approx .1 point in compression :D

I will email you later.

thanks Mike!
I use the 4.166"

Originally posted by Motor Martyr:

Lonnie,
the Belt drive is worth ET simply because i can stage the car cooler and more consistantly cooler at that. A guy at work was wanting to try an electric for ET and asked me about it. I had forgotten you had an electric drive. I remembered Ed has one that's why I asked. I would think it's worth some ET, maybe not.

I'm getting 9.88:1 for you now, I must have punched in a wrong number before. My mistake.

maybe it is, but personally, i dont want to turn my water pump 6000rpms.

I would bet its worth a little, but the real power is in a low water temperature into the water box.

At the end of the pass if i go into the water at the right temperature i'll finish the pass and get to the slip booth at 175 degrees.
I go in the box at 140.

Small blocks are more sensitive to temp than rats in my experience.
I have always tried to run my rat at 165 water temp, but when you get into the final rounds, forget that. You go to the line when they wave you up. Even at 190, the ET remains the same. I know it depends a bit on carb jetting, but still I feel larger engines vary less. I also run an engine driven water pump. I drive my car 40 miles to the track, and the electric pumps and fans just don't cut it.
Ron