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Discussion Starter · #21 · (Edited)
Hey Chris

I think I would be very happy with anything over the 700hp mark

there a good chance I’m getting on a hub chassis dyno this week and my builder will be there as well to tune it. Then I’ll have a real base number to work off I guess. The motor will never be optimal as it’s in a a real street car with 2” primary headers and a strip dominator single plane with no room for a spacer as it barely clears the cowl hood as is

my car feels very similar to my buddys 69 chevelle with a Pat mussi 555 fuel injected crate motor. Motor was dyno’d at 737hp and it made exactly 600hp on a chassis dyno

his car is probably 500lbs heavier than mine

both stick cars with 275 60 tires
 

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Hey Chris

I think I would be very happy with anything over the 700hp mark

there a good chance I’m getting on a hub chassis dyno this week and my builder will be there as well to tune it. Then I’ll have a real base number to work off I guess. The motor will never be optimal as it’s in a a real street car with 2” primary headers and a strip dominator single plane with no room for a spacer as it barely clears the cowl hood as is

my car feels very similar to my buddys 69 chevelle with a Pat mussi 555 fuel injected crate motor. Motor was dyno’d at 737hp and it made exactly 600hp on a chassis dyno

his car is probably 500lbs heavier than mine

both stick cars with 275 60 tires
chassis after engine dyno sessions are the best.

Do you know your buddies accessory drive? Like: (heavy/standard) duty fan clutch with 5 or 7 blade fan and mech waterpump? Or full electrical cooling?

Also: stick means muncie? or TKO/t56?

I feel you with the "in car" deviation from engine dyno setup.
I also only can use a 1/2 spacer instead of 1" which it was dynoed with.
At least i got the 2" into 3.5" headers with el. cutouts to make it "dyno mode" when i oped the cutout ^^
 

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Discussion Starter · #23 ·
My buddy’s chevelle is full electrical cooling. T56 magnum with McLeod rxt twin clutch. Moser 12 bolt

mine is more of a budget friendly build. Full electrical cooling,new tkx with .68OD, McLeod rst twin clutch and a built stock12bolt

I also have the cutouts installed in the exhaust system, but I removed the electric cutouts due to them always leaking. So I can remove the block off plates manually if wanted. Might try that on the dyno to see the difference
 

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Hey Chris

I think I would be very happy with anything over the 700hp mark

there a good chance I’m getting on a hub chassis dyno this week and my builder will be there as well to tune it. Then I’ll have a real base number to work off I guess. The motor will never be optimal as it’s in a a real street car with 2” primary headers and a strip dominator single plane with no room for a spacer as it barely clears the cowl hood as is

my car feels very similar to my buddys 69 chevelle with a Pat mussi 555 fuel injected crate motor. Motor was dyno’d at 737hp and it made exactly 600hp on a chassis dyno

his car is probably 500lbs heavier than mine

both stick cars with 275 60 tires
The heads out of the box will reach you goal with just a camshaft change. Max power around 6300 rpm
 

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Discussion Starter · #25 ·
That’s kind of what I thought. I know most people don’t think the 270 rr oval is even close to big enough for a 540bbc, but they make my car move pretty good. So if a stock cnc version can make 700hp at 6300, could a ported set make even more power at 6300?

My heads and can we’re both spaced by Mike Lewis originally for the purpose of being a street only car and having good manners at low rpm cruising. And he nailed the combo.

Im just now trying to get the most out of this setup.

Maybe a good option is to have the heads and intake ported and get flow numbers, then get a cam to match the head flow?

As is it’s a hydraulic roller cam but I couldn’t stand the noise and valve float of the morel sportsman lifters no matter how tight we set them, so it’s now a hybrid set up as I’m running isky ez solid rollers lashed at about .004 cold
 
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HOw did the solid rollers affect the manners and powerband?

What clutch slave/bracker are you using?
1 gen Camaros my all time fav car

With that level of power, a 6 spd curious as to what axle ratio you run and at what point can you dig into the throttle where its not spinning constantly? Never ridden in an NA car with that much oomph
 

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Discussion Starter · #28 · (Edited)
Solid rollers completely changed the motor for me

the hydraulics were always noisy. When I would start the car or cruise on the highway for an extended period the car would sound like volkswagon hahaha. And near 6k rpm it was floating the valves and the rpm we bounce around

solid rollers sound great, but best of all the motors just feels so smooth through the whole rpm range

I’m using American power train hydraulic set up pedal and throw out bearing. Great setup. Very happy with pedal feel

edit

mine is a new tkx. It’s a 5 speed with .68od and I run a 275-60-15 with 3.55 gears now

the 3.73 were great too but harder to get traction. I would slip then grab 1st through 3rd if I launched in the street. 4th would always just grab and go. That’s with Mickey Thompson et streets
 

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Discussion Starter · #29 ·
Booxr800

maybe I could sell you my 270s and put that towards a bigger head. Just a thought
 

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Discussion Starter · #31 ·
I would think the 270 should be on your short list for sure. Also look at the afr 265 for a 427. But a lot of the guys here know way more than I do. That’s why I’m asking about my options
 

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Im of no help at all lol
Will have to look American powertrains site up for their slave setup
solid rollers sound great, but best of all the motors just feels so smooth through the whole rpm range
Amen to that! same reason i love em, even flat tappets. Never feels like its working to get more rpm esp upstairs. They just keep going! Sounds like a wild ride to tear up D.R. through the gears wow.

Just read up on that TKX...that is a badazz trans. Tempting to swap out my T56...6 is still too tall for me. Is the drop from 1st to 2nd feel like a bunch? Hate to ask too many Q
 

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Discussion Starter · #33 ·
No worries bud

that’s what this forum is for haha

drop from 1 to 2 isn’t bad at all

the only big drop is 4 to 5 which is fine with me

3 through 4 is right in the money. Great tranny. Nice upgrade in feel from the tko600 I had before
 

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hats off.
somehow you and mark jones are the guys achieving the best lbft/cui numbers (1.33+) which also come in already mid 4000s, all the time.
Thats one of my personal indicators of good work.
Especially when talking street hyd roller engines..

One question though:
In what way can a head supporting lets say 350 cfm at .600 lift, be too small for a street 540 with lets say a goal of 650hp?

I am talking about AFR 265s for example or any other head with small CSA (below 270) and good flow (350+).
I dont understand.
How can more demand (e.g. 540 vs 496) be a bad thing, if head is able to supply up to 700 hp (2x 350cfm) within hyd.roller rpm range (up to 6500)?
I know you can overcharge a chamber, but doesnt that only apply when going high rpm?
Isnt demand THE way to increase low end torque for street engines?


For example i run a MJ496, 049 heads on 496 cui with a 238 hyd roller cam and dual plane.
It makes 670hp at 6k but also drives like a granny car, so willingly accepting throttle inputs at 1500 rpm and up. Its almost like a stock car to me.
And i think not only the short cam and the dual plane, but also the "small" CSA 049 heads play their part there..
Thanks for the compliments, although I think there are quite a few builders more than capable of doing it, they just aren't on forums generally.

I didn't say the head didn't flow enough to support 650hp, I just noted that the CSA is too small for the CI it has to feed at RPM. Flow a head at 10", then 25", 28", then 40"-60". What's that airpseed doing? Now whats the airspeed on that 270cc port on 67.5ci vs 57.5ci? Sonic choke, pumping losses, etc.
Does it do any good to blow the intake charge out the exhaust even at low rpm?
The demand is already there, but can you feed it enough to do it's job or is it sucking through a straw to make the power?

For example i run a MJ496, 049 heads on 496 cui with a 238 hyd roller cam and dual plane.
It makes 670hp at 6k but also drives like a granny car, so willingly accepting throttle inputs at 1500 rpm and up
Mark has developed an excellent package, the short cam timing makes good manners and combined with a head CSA that works well together.


CPMotorworks your 540 with the 294 rr might be peaking early but doesn’t fall on its face after 6000rpm either. And it’s making probably close to 75hp+ than mine in the same rpm range

wouldn’t that setup be exactly what one would want in a real street car?
In the car is a little different than the dyno, but with the heavy intake valve and what I like for a spring with Morel Street series lifters, 6200 is about it. The above 750hp 540 is in a REAL steet car, PS, PB, AC, Tremec 5 speed, 17" wheels, full exhaust, etc. She is EXTREMELY happy with it, as is her boyfriend who hired me to build it. I honestly didn't expect it to make that much power, and regret not putting a short travel lifter in it for more RPM ability.
I used 2 sets of the Morel 4603's about 12 years ago, and while they performed past 6500 well, the noise was not something I cared for. I've used the Street Series in pretty much every engine I've built the last 12 years, with good results. However, after waiting 7 months last year for lifters, I bought 4 sets of the Isky/Johnson Silver series to try. First set I just tried about a month ago, and they performed very well, but the head/intake combo I had to retrofit was sub par, so it wasn't a stellar performer imo. But in the car with full exhaust, nice and quiet, just a mild mechanical sound from the valvetrain. So although they are quite a bit pricier than a Street Series Morel, the Isky/Johnson will get more use from me in builds that have the potential to run more than 6k.

Plumbing valve Electrical wiring Engineering Gas Machine
 

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From what I gathered from this over the years is it’s not possible to make it well mannered down low and have it make big power on top end but……

possibly have it well mannered down low and peak around 6000 but able to maintain until around 6500?

Not sure if that possible or not.
Well-mannered is a subjective term, everyone's definition of that is different.
I consider my 532 well-mannered with a 268/271 @ .050 cam making north of 800hp/700tq using a T400.
But then again it also has a 4500rpm stall speed.
Having a stick will compensate for some of the milder ill-mannered tendencies over the auto.

But.

I'm with mr4speed on leaving it alone.
It would be at least triple you initial intended budget for moderate gains in the scope of things without including this next issue.
Basically, any head that will outperform your current heads will put you into raised exhaust ports and having to change/alter the headers and exhaust.
Fitting large tube primary headers for raised ports is a pain and or expensive.
Like a $1500.00 set of Lemons.

Just a little more fuel for thought.
 

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If you need to spend money, buy parts and change the combo. Porting what you have is a large cost for minimal gains. But there is also not much point in trying to make a ton of power when you are limited by other parts that can't support the power.
 

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Discussion Starter · #38 ·
I get what you guys are saying. Hopefully when I get it in the chassis dyno my builder will be able to get the most out of the current combo and I will be happy with that for now. It does run really well and maybe there’s a few ponies left in her too

The actual cost a a head, intake and cam swap all said and done with labour and supporting parts would be really high for another possible 70hp

Like Straub said, my current heads will support 700hp so I think that is my end goal at this time now

If I get On the dyno this Thursday I’ll post my numbers up

Much appreciated guys
 
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1968 Malibu sport coupe, 489 ci. 590 hp 600 tq, RV T-400 Freakshow 3200 stall, 3.73 12 bolt posi
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I think I read you have ET rear tires? you might want to ask the chassis dyno shop if they're OK with those, I stopped by a local dyno shop and the owner said they wont dyno cars with DR tires, my engine was dyno'ed and wanted to find out the drive train drag but haven't yet, DR's on 2 sets of rear wheels unless I borrow some decent street tires, anyway doesn't hurt to ask the shop before getting there
 
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