Ok, here's the deal....

I'm posting this for Nick...Vettemaniac....he's on vacation this week and is in a delima.

As some of you may remember, Nicks pump gas 632 was a victim of some really crappy machine work from a shop in Dallas that machined/balanced and assembled the shortblock. Of course, the sleezball is no help when it scatters during dyno testing when the lifters all stuck in their bores with only .0005 or less clearance. Anyway...I digress.......

He is in the middle of reassembly and is debating looking for new heads to add some power. He used some Brodix CNC 3Xtra's (Thanks Wolfplace!)that had even some more port work done on them by an excellent shop. With all the issues the motor was having, it still made just under 900HP before it died.

We figure we can easily break 900 hp this time around with all the issues resolved, but he's been thinking he may have went too small on the heads. Now you know me...I was pushing for Big Dukes or Chiefs from the start..but he's resisted the temptation.

This will be a real street car and his goal it to run Drag Week in the N/A class with an IRS suspension 6 speed N/A Vette next year.

So, does anyone know anyone with real experience with something like the Brodix -4Xtra CNC heads or anything equivalent? Maybe the BMF 385's? Or the Dart 410's? The pistons are here already, so other than a little notching, he wants to retain the ones he has, so that limits choices some.

My gut tells me that short of a full on killer hog out port job, I don't think we're going to gain much...maybe 20-30 hp tops? He already has a full T&D shaft rocker setup, so changing heads will likely mess up that plan too.

What's the most anyone has ever seen from a conventional headed, pump gas 598/632" size motor with an under .750 lift cam? I'm thinking the cam limitations are going to be a deciding factor since the big heads really shine with .900+lift or so.

The interesting thing was that the motor was still pulling hard at 7000 rpm and wasn't dropping much at that point..so we figure we really don't want to spin it any higher with the steel rods and that stroke. But with that many cubes were' wondering if it couldn't benefit from the increased crossectional area even at lower speeds?

How 'bout a bigger intake? He has a ported Super Victor now and most folks are saying to stick with it or move on to a full out Sonny's...but it will need porting too. He is currently using an 1150 AED....which picked up 30HP over a 1050. I think a 1250 will be tested next time around!

Man...a set of Dukes or Chiefs would have us looking at 1050HP at least!! Oh well...what do you guys think?


JIM

going with dukes or chiefs is not going to be feasable specialy with the pistons that are being used. also the only way to controll the valves on big dukes or chiefs is to go titanium especially with more lift. a bigger head is not going to do squat if you dont have the correct cam. but the corect cam will not be streetable.

My opinion - .750"+ lift cam and 632 inches and any of the above heads is.....

a waste of cubic inches.

There are small block heads that now flow as much as the heads you are talking about - why would you put them on an engine half again bigger??

I would run a smallish cam and run a PB1200 head if I was building a pump gas 632 again... :drool:

I'm with you.....it's been a long deal. I figure I'll have some little Dukes on my 540 before he does!

He has always wanted a 632..even when he was building his previous 540. During its upgrades he picked heads that would also work OK on his future 632. Then he sold it (it had AFR 357's at the end) and started assembling pieces for the 632. Considering his plans of driving it crosscountry, and using a 6 speed with O/D, he has tried to pick his parts for that use. It has to cruise around in the 2000-2300 rpm range in high gear, so even with a big engine, there are limits. His cam is in the 277/282* range, but not a whole lot of lift..again for durability.

So again, he is building his dream motor and wants as much power as he can without having to build complete custom headers, using race gas or spraying it. He's got it all now...just hoping to maximaize it the best we can. Without *real* porting, the regular style heads will definitely have a tough time feeding it, but he's not ready for Chiefs or Dukes and all the extra $$$ that go with them.

So Ryan....do you know of any conventional head tests on 632's? I know Harold Sutton is doing pretty decent with just a set of 357AFR's on his 598"..so there's gotta be a place here somewhere.

BTW- what kind of RPM did you spin the 632? It was a steel rod motor too right?


JIM

Jim, not to sound too harsh but he has to get real about what he is trying to do. If you are going to build a 632 worth being a 632, ya gotta put 18* or better heads on it. A 632 with a 6 speed, small tires, small heads and an IRS on a race track .....you have to be kidding me. You know as well as I do how much of a PIA that car will be to get down the track.

If he is doing it just because he HAS to have a 632 and is unwilling to run 18* heads; maybe check with Rehermorrison about their Beast 370 heads.

You could also check racingjunk for a set of used heads from a guy stepping up to Raptors and wanting to get rid of Dukes or Chiefs, this is the time of year guys are selling stuff. Might even find some with pistons, probably be 14 to 1 though....

If he ever wants to sell those -3's let me know.

Ok, here's the deal....

I'm posting this for Nick...Vettemaniac....he's on vacation this week and is in a delima.

As some of you may remember, Nicks pump gas 632 was a victim of some really crappy machine work from a shop in Dallas that machined/balanced and assembled the shortblock. Of course, the sleezball is no help when it scatters during dyno testing when the lifters all stuck in their bores with only .0005 or less clearance. Anyway...I digress.......

He is in the middle of reassembly and is debating looking for new heads to add some power. He used some Brodix CNC 3Xtra's (Thanks Wolfplace!)that had even some more port work done on them by an excellent shop. With all the issues the motor was having, it still made just under 900HP before it died.

We figure we can easily break 900 hp this time around with all the issues resolved, but he's been thinking he may have went too small on the heads. Now you know me...I was pushing for Big Dukes or Chiefs from the start..but he's resisted the temptation.

This will be a real street car and his goal it to run Drag Week in the N/A class with an IRS suspension 6 speed N/A Vette next year.

So, does anyone know anyone with real experience with something like the Brodix -4Xtra CNC heads or anything equivalent? Maybe the BMF 385's? Or the Dart 410's? The pistons are here already, so other than a little notching, he wants to retain the ones he has, so that limits choices some.

My gut tells me that short of a full on killer hog out port job, I don't think we're going to gain much...maybe 20-30 hp tops? He already has a full T&D shaft rocker setup, so changing heads will likely mess up that plan too.

What's the most anyone has ever seen from a conventional headed, pump gas 598/632" size motor with an under .750 lift cam? I'm thinking the cam limitations are going to be a deciding factor since the big heads really shine with .900+lift or so.

The interesting thing was that the motor was still pulling hard at 7000 rpm and wasn't dropping much at that point..so we figure we really don't want to spin it any higher with the steel rods and that stroke. But with that many cubes were' wondering if it couldn't benefit from the increased crossectional area even at lower speeds?

How 'bout a bigger intake? He has a ported Super Victor now and most folks are saying to stick with it or move on to a full out Sonny's...but it will need porting too. He is currently using an 1150 AED....which picked up 30HP over a 1050. I think a 1250 will be tested next time around!

Man...a set of Dukes or Chiefs would have us looking at 1050HP at least!! Oh well...what do you guys think?


JIM Hi Jim, I don't think your friend is that far off base. My son has a good racing buddy with three big motors. The 615" one with Raptor heads doesn't run any harder than the two slightly smaller ones. One is a 598" with Brodix CNC -2Xtra heads and the other is a 605 with the Edelbrock Musi heads. Of the three the one with the smaller Brodix heads runs the best on nitrous. My son's with the AFR CNC 357's goes extremely hard too. The bigger heads aren't really necessary on the big motors. You might try to get him to cam it up a little as this guys 598" goes 8000 easily and he commented that it had way more torque and pulled harder than the Raptor headed motor which at the time was 622 inches. Most of ours have about .800 lift and 285/295 duration cams with lots of compression so that might be the only other variable. A guy at the Clash race has a short deck (9.8") 598" with 6.385 steel Oliver rods and it flys. That motor made 974 H.P. but constantly outruns his friends 632" Chevelle which had been dynoed at 1140 H.P. and is carrying less weight. This might be from his nitrous working better though. The dyno doesn't tell everything you need to know about the big motors. I think that the 383 CC oval port Dart head which has 18* valve angles will make the most power of all the conventional heads but a good port job might be just as important. A call to R-M will get you a good cam recommendation. How much compression does the 632" have? If you could get the SAM school guys or Darin Morgan to do some minor porting it might do more good than changing the heads to a different type. The difference is in the details.

Harold, something does not add up there, but what do I know.

I agree John.

The same car ran 8.09 with the 598" and the Brodix -2 extras and finally after a year of constant testing the Raptor headed motor went 7.99 at about the same speed. Basically he said the small headed motor had more mid range power. Musi said the difference between the 598" and 632" was 20 ft. lbs. of torque and no H.P. If anybody wants to go really fast a Turbo is the only way to go as it makes engine size unimportant and you can drive it around all you want. All power adders have drawbacks though.

The same car ran 8.09 with the 598" and the Brodix -2 extras and finally after a year of constant testing the Raptor headed motor went 7.99 at about the same speed. Basically he said the small headed motor had more mid range power. Musi said the difference between the 598" and 632" was 20 ft. lbs. of torque and no H.P. If anybody wants to go really fast a Turbo is the only way to go as it makes engine size unimportant and you can drive it around all you want. All power adders have drawbacks though.

I do not doubt what you are saying Harold, but -2's on a 598 are only .1 slower than a set of Raptors ??? Did they guy have the Raptors on up side down ??

Not to start another thread, but I agree with part of what you are saying about turbos. They make a heck of a lot of power but no body has yet figured out how to get all that potential down the track. They are still being outrun by blown alcohol and even the big nitrous motor in Pro-Mod. That being said they will eventually figure it out.

Maybe the guy did not optimize the rest of the combination to take advantage of the Raptors i.e., giant cam, lots of rpms, and tons of compression. The only way I could see -2's hanging with Raptors is with 9 to 1 compression, 6000 rpm shift points and a 225 @ .050 hydraulic flat tappet cam.

I do not doubt what you are saying Harold, but -2's on a 598 are only .1 slower than a set of Raptors ??? Did they guy have the Raptors on up side down ??

Not to start another thread, but I agree with part of what you are saying about turbos. They make a heck of a lot of power but no body has yet figured out how to get all that potential down the track. They are still being outrun by blown alcohol and even the big nitrous motor in Pro-Mod. That being said they will eventually figure it out. Hi John, I think the Raptors were just to big to make decent mid range torque. They shine now that he has a ton of nitrous on them but they wouldn't get out of their own way for quite a while. The Brodix 1803 head is a good one but not substainially faster the the mid size convential heads. Huettel (pronounced U-Tell) has worked over "old" 360 Dart castings which flow 454 CFM after porting and he was faster than everybody at the Clash race in our TT5 class, turbos and all. He was 250 lbs. over minimum weight too, 3355 vs. to a minimum of 3100 and the only car to run 7s.

Hard to argue with R and D at the track.

Good stuff, makes me want to out to my garage and look at my little oval port heads. Ha ha.

66 283,

I just caught that the PB1200's are actually GREAT BIG large ovals!!

I always figured an oval port would flow better than the same cc sized rect. port for NO other reason than it will have a shorter wall circumference than a rect. port will have so thus should have LESS wall flow friction loss.

As always, jmho..

pdq67

For what it's worth, I have BMF 385's on my 15:1 632 and It made 1094 hp on Schmidts dyno...

For what it's worth, I have BMF 385's on my 15:1 632 and It made 1094 hp on Schmidts dyno...

Good info, where did it make max power, cam specs ??

1094 hp @ 7300 and 894 tq @ 5900

.824 lift on the intake and .800 on the exhaust
Duration @ .050 is 289 intake and 306 exhaust

A couple things.

1st a caveat -- a 632 is way out of my league and nothing that I've done before. ;)

2nd -- having done drag week two years in a row I would highly recommend that you check the rules because there were some cubic inch limits in the NA Street Race categories last year. I believe 632 was too big for street race last year -- might be just fine for prostreet or some other class, but then you may be competing with N2O or other power adder cars.

3rd -- according to Vizards limiting port velocity formula a 632" motor would need a port with AT LEAST a port cross-section of 3.60 sq.in. for peak power at 7000 RPM. Now Vizard's formula uses 690 fps as the choke point and assumes speed of sound at 1200 fps. Other formulas out there may recommend slightly more port cross-section -- his tends to recommend ports on the small side by a few %

Please don't shoot me for mentioning Vizard . . . I just happen to find the LVP formula in his book and find it helpful for these type of things.

Bang, bang.

Ok, here's the deal....

I'm posting this for Nick...Vettemaniac....he's on vacation this week and is in a delima.

As some of you may remember, Nicks pump gas 632 was a victim of some really crappy machine work from a shop in Dallas that machined/balanced and assembled the shortblock. Of course, the sleezball is no help when it scatters during dyno testing when the lifters all stuck in their bores with only .0005 or less clearance. Anyway...I digress.......

He is in the middle of reassembly and is debating looking for new heads to add some power. He used some Brodix CNC 3Xtra's (Thanks Wolfplace!)that had even some more port work done on them by an excellent shop. With all the issues the motor was having, it still made just under 900HP before it died.

We figure we can easily break 900 hp this time around with all the issues resolved, but he's been thinking he may have went too small on the heads. Now you know me...I was pushing for Big Dukes or Chiefs from the start..but he's resisted the temptation.

This will be a real street car and his goal it to run Drag Week in the N/A class with an IRS suspension 6 speed N/A Vette next year.

So, does anyone know anyone with real experience with something like the Brodix -4Xtra CNC heads or anything equivalent? Maybe the BMF 385's? Or the Dart 410's? The pistons are here already, so other than a little notching, he wants to retain the ones he has, so that limits choices some.

My gut tells me that short of a full on killer hog out port job, I don't think we're going to gain much...maybe 20-30 hp tops? He already has a full T&D shaft rocker setup, so changing heads will likely mess up that plan too.

What's the most anyone has ever seen from a conventional headed, pump gas 598/632" size motor with an under .750 lift cam? I'm thinking the cam limitations are going to be a deciding factor since the big heads really shine with .900+lift or so.

The interesting thing was that the motor was still pulling hard at 7000 rpm and wasn't dropping much at that point..so we figure we really don't want to spin it any higher with the steel rods and that stroke. But with that many cubes were' wondering if it couldn't benefit from the increased crossectional area even at lower speeds?

How 'bout a bigger intake? He has a ported Super Victor now and most folks are saying to stick with it or move on to a full out Sonny's...but it will need porting too. He is currently using an 1150 AED....which picked up 30HP over a 1050. I think a 1250 will be tested next time around!

Man...a set of Dukes or Chiefs would have us looking at 1050HP at least!! Oh well...what do you guys think?


JIM

What is his max rpm he going to turn the engine?

Chris

Chris, probably 7000 rpm or so..maybe 7200 through the traps.

All motor, no juice or boost.

JIM

Jim,
Is this a 4.750 stroke? If so his piston speed is 5700 FPM at 7200 rpm. Exceeding 5280 FPM is DANGEROUS. The engine will be in self destruct mode.

These BB3X dont have enough valve area for the 632 x 7200 either. So the heads are a restricition if the guy wants to turn this kind of RPM. If he still wants to use them then a camshaft in the mid 800 lift range will be needed to crutch the head to make power to that rpm.

If he wants to keep it a max of 6000 rpm the heads are sufficient.

Thanks Chris...I put the 7200 limit out there as an extreme outer edge. Yes it's a 4.750 stroke. During the last dyno pulls it was still pulling well at 6700 rpm...which was actually higher than we expected. It was peaking right around there.

Even with all the engines problems, luckily the bearings still looked like they came out of the box..but granted..that's just a few dyno pulls.

We had expected it to peak in the 6400-6600 range max and was what we were aiming for taking into consideration the piston speed as you mentioned.

I know if another 632 with 12.0 compression, older Big Chiefs and a .850 lift cam that made right at 1175-1200 hp it seems like. It was a N20 motor and it was cammed for nitrous, so making that power with a non N/A type cam it was doing pretty well.

Another friend picked up 90-100 hp on his 572 going from a smaller set of ported Brodix to a set of older Dart Chiefs .Same cam.

So that seems to be a trend here.

Thanks for the info guys...please keep it coming. He will either need to set sights on lower HP. Lower RPM or bigger budget!!

Harold..great info...still digesting it all. BTW- It's an 11.2 compression motor I believe.

Gary.....any word on those -4's? It's those heads that have him thinking about all of this!

8sec71- That's very interesting on those BMF's. I know of another shop that gave very similar numbers for a high compression 632 they did with the 385's. They are a sweet looking head!

JIM

Maybe the guy did not optimize the rest of the combination to take advantage of the Raptors i.e., giant cam, lots of rpms, and tons of compression. The only way I could see -2's hanging with Raptors is with 9 to 1 compression, 6000 rpm shift points and a 225 @ .050 hydraulic flat tappet cam. The Raptor headed motor has a sheet metal tunnel ram and two dominators and only recently started to run faster with a Speedtech third stage of nitrous down the plemnum and a 7531 box added. He has an almost .900 lift cam and winds it 8000+ RPM. When he had the 598" motor with one dominator the car weighed 3350 lbs. and it now weighes 3180 lbs. and has run 7.82 @ 180 with the aluminum motor at 615 cubic inches. This motor has Dynoed at over 1170 H.P. at R-M but still isn't that much faster than the 598" in another Camaro which is 300 lb. heavier. The 598" holds the record for the class at 8.20 @ 169.72 MPH in 100 degree heat (4000+ ft. D.A. day). At the Clash race a Camaro from Houston ran 7.91 @ 178.8 with an old set of 360 Dart heads and one Dominator. That car is 3355 lbs. with driver.

For what it's worth, I have BMF 385's on my 15:1 632 and It made 1094 hp on Schmidts dyno... This car is going to be fast. It's already run 10.40 on a badly busted up run and was going 113.4 at the eighth. When he gets the gear where it needs to be i see low 9s or better.

If Nick's staying w/ conventional heads, then I'd recommend the BMF's in 385 cc configuration or the 18 degree Dart 383 oval port heads. I've heard good things about both. Of course to maximize the combo, the intake will need to be matched accordingly. Not sure its all worth scrapping his current Brodix heads however....

I suppose if he's swapping heads, he's not averse to swapping pistons? I believe the Dart 18 degree stuff takes dedicated pistons. At that stage, he may well be better served going the Big Chief/Duke route.

Is his current 11:1 CR inviolate?

Mark

He wants to stay pump gas.....in fact he wasn't worried too much if it dropped a few tenths for cushion.

He already has new pistons for it, so we're limited a little with valve placement options unless he starts all over. Plus of course he already has the T&D's for the Brodix -3's. Not sure how transferrable they are to other heads yet.

The only issue I've heard on the BMF's is some casting integrity issues at the larger 385cc range?

They are basically Canfields CNC'd right?


JIM

He wants to stay pump gas.....in fact he wasn't worried too much if it dropped a few tenths for cushion.

He already has new pistons for it, so we're limited a little with valve placement options unless he starts all over. Plus of course he already has the T&D's for the Brodix -3's. Not sure how transferrable they are to other heads yet.

The only issue I've heard on the BMF's is some casting integrity issues at the larger 385cc range?

They are basically Canfields CNC'd right?


JIM I think they are still Canfield castings and they do make tremendous power. I've heard the same thing about cracking. I also heard that Jegs bought the whole Canfield company but don't know how much fact there is in that. There is one '69 Camaro here that has a 11-1 compression 632 with a Donovan aluminum block. It has 1803 Brodix big dukes and has run 8.86 @ 153 with a run weight of 3180, on motor only. I would think the Brodix -3 heads could be ported into the 380 CC range and gain what is needed for the big motor and probably work much better than an off the shelf head. I think my son's 598 with the AFR's makes quite a bit but have never had it on a Dyno.

I think they are still Canfield castings and they do make tremendous power. I've heard the same thing about cracking. I also heard that Jegs bought the whole Canfield company but don't know how much fact there is in that. There is one '69 Camaro here that has a 11-1 compression 632 with a Donovan aluminum block. It has 1803 Brodix big dukes and has run 8.86 @ 153 with a run weight of 3180, on motor only. I would think the Brodix -3 heads could be ported into the 380 CC range and gain what is needed for the big motor and probably work much better than an off the shelf head. I think my son's 598 with the AFR's makes quite a bit but have never had it on a Dyno.


Canfield has not be sold to Jegs. I just spoke to John the other day and they are several hundred sets of casting behind.

Chris

Jim,
Is this a 4.750 stroke? If so his piston speed is 5700 FPM at 7200 rpm. Exceeding 5280 FPM is DANGEROUS. The engine will be in self destruct mode.

These BB3X dont have enough valve area for the 632 x 7200 either. So the heads are a restricition if the guy wants to turn this kind of RPM. If he still wants to use them then a camshaft in the mid 800 lift range will be needed to crutch the head to make power to that rpm.

If he wants to keep it a max of 6000 rpm the heads are sufficient.

1)Vizard WHO?
2)7200rpm from a 632 is not dangerous - 8000 is commonplace, and if you ask Sonny Leonard he claims they don't make power unless you spin them to almost 9K... Alum rods, true, but a billet steel rod at 7500 can be done with a bracket car pass after pass after pass - it has been proven so you can put your calculator away LOL

1)Vizard WHO?
2)7200rpm from a 632 is not dangerous - 8000 is commonplace, and if you ask Sonny Leonard he claims they don't make power unless you spin them to almost 9K... Alum rods, true, but a billet steel rod at 7500 can be done with a bracket car pass after pass after pass - it has been proven so you can put your calculator away LOL

I knew you could not resist Ryan.......LOL

Chris is only stating that 5280 FPM is considered the safe design limit for parts currently available. He didn't make this up, it's a design reality put out by the SAE. I'm even more concerned that exceeding 170 MPH in the traps can make a car fly. My son is going to sit out the last race because the cars are getting to a point of unsafe trap speeds. The Camaros that are running in the shootouts here are at that point now and without additional aerodynamic modifications it's very risky.

Chris is only stating that exceeding the 5280 FPM is considered the safe design limit for current technology. I'm even more concerned that exceeding 170 MPH in the traps can make a car fly and maybe crash. My son is going to sit out the last race because the cars are getting to a point of unsafe trap speeds. The Camaros that are running in the shootouts here are at that point now and without additional aerodynamic modifications it's very risky.

Harold, are you guys running any aerodynamic stuff at all ?? How about the Camaros?

Harold, are you guys running any aerodynamic stuff at all ?? How about the Camaros? Nothing yet, that is why my son's opting out before getting hurt. I tried to get him to close part of the grille off and put something under the bumper to keep excess air out from under the car. The '63-67 Vettes look real nice when a spoiler is added under the front end like the Suncoast bodies.

1)Vizard WHO?
2)7200rpm from a 632 is not dangerous - 8000 is commonplace, and if you ask Sonny Leonard he claims they don't make power unless you spin them to almost 9K... Alum rods, true, but a billet steel rod at 7500 can be done with a bracket car pass after pass after pass - it has been proven so you can put your calculator away LOL

1) I never brought Vizard up but do respect his opinion.

2) Any 632 that is goin to spin that high is a dry sump engine, Chief/Profiler/or Duke headed.

3)I hope everyone uses a calculator when they figure and build an engine.

4) Piston speed is something that needs to play into any engine build because it can be your friend or it can be a killer.

66 let me invite you over to www.speedtalk.com It may be a sight that will enlighten you somewhat.

I knew the "V word" would incite violent thoughts in someone's mind. :D

My point is merely to consider port velocity when looking at these sewer pipe sized ports. A little math might help get you in the ball park on port size.

And speedtalk is definately a good place for talking tech on heads :)

I wished more people would use calculators it would save them a ton of cash in the long run. I have 3 engine projects that I am working on currently that customers were talked into parts that if they had just used some simple formulas and not listened to the graduates of "Bench Racing U" they would be 1000's of $$$ less into projects. On example is a $3500 set dominators that have been out HP and out torqued buy a set of 750's with some mild work on a 598 blown BBC. The customer did not base his decision off of some simple math to figure carb requirements but instead got talked into the bigger is better plan. So he now has 1200 cfm more capacity then the engine will ever use.

So I would suggest to use that $5 calculator because it could save you a few thousand $$$

7000-7500 is hardly a sweat for an engine that's built for it IMO. We're not talking about hydraulic cams, weak valve springs, OEM rods and heavy pistons. We're also not talking about a road racing engine, we're looking at getting over 7000 for a fraction of a 9 seconds pass. Plus how often will you spin a 632 to redline on the street? Heck how often will you even get past half throttle with a 632 on the street? :P

I have a $30 calculator because I'm a professional engineer and that's how we roll. BUT just because you can "calculate it" doesn't mean it's meaningful. Most of what is used today was not derived from calculations but rather the painful way - trial and error. Sure, some try to back-calculate to match the empirical numbers LOL but it's much cheaper and more reliable to find someone who has been there done that to save us the trouble. Fact is - we are so far back from the cutting edge we should put our calculators down, shut up and listen.

And ironically the hillbillies who can't read have developed a lot more horsepower that we ever will!

BTW i clicked the link and ironically I have had the reher morrison books for years and have read them several times - very good "no bull" info. Can't say the same (in my opinion) of the V word. I trust the guys building and racing more than I do journalists.

And to answer 454's question about how often you get to redline on the street with a 632: "Every chance I get."

The question 66 283 is who to believe. Lots of people have "been there and done that" with widely varying opinions.

Now that everyone has beat this subject to death, I'd like to say one thing. Nitrous isn't cheating, it's a way to shut off half the horsepower and compression in your engine while your on the street. I know he doesn't want to spray it, but consider this. He can get away with smaller heads, cam, and pistons making it more streetable and run race gas and juice when he gets to the track. Another thing to consider, it's an IRS car! Like the other guy said, does he know what that thing is going to be like launching?! Holy Crap! I have a friend with a 4000 lb Nova that runs 9.00 in the 1/4 at a 157 with a bb2x headed 468. This guy is talking about enough motor for a pro-mod! Build a whole car, not just the engine. You build 5000 hp if you want, but it don't mean squat if you can't put it on the ground.

P.S. The guy with the Nova has dynoed 652hp on the motor and 2 stages of juice, 200 and 400. He drives the car every day. It has a back seat, steal hood and fenders, 4 speaker stereo, headliner, carpet, etc, etc. Ain't that kinda what this guy is after?

Nick is an engineer by trade, so he usually calculates everything 12 different ways before he jumps. This 632 project has taken the direction that so amny of us have had. Originally he literally drove this '72 Vette to work everyday in Dallas traffic with the 540. I mean it WAS his only means of transportation for a long time. He wanted some power, but it had to have drop dead reliability. Hence the combo I pick on him a lot about as being way too mild. But truthfully it was exactly what he wanted at the time.

Then he got the HP bug and started adding power to the 540 with better cam, heads, intake, carb etc. But the idea of building a 632 along the same lines as a 540...just bigger was still in his head.

So that's why it started out as it was. It needed to fit in the car easily, take crosscountry trips etc just like the 540.

But then he started getting real crazy. Pump Gas drags appeared......Drag Week came along and he started looking heavily at taking a stab at it. He likes N/A racing so he is loooking that way. I gotta check the cube rules that Eric mentioned..that's going to ruin his day if that is right! Regardless, since the original purchase of all his parts, the car's direction has changed a good bit. So that's why we're trying to do the "most with the least changes and $$" at this point. He hasn't cut any corners on it so far....he bought good parts the first time around.

The car is being completely done from a frame and a body now. It's getting a full cage and reinforcing, lots of lightening etc. But it will have nice paint, interior, stereo etc. Even A/C!! He wants to keep the IRS configration. just 'cause that's how Vette's are. We have another fabricated Dana 60 IRS similar to mine to install in it, except his has a spool. We know we can get the IRS to hook OK.....it will just take some work.

There are definitely some basic piston speed issues here. A 632 at 7200 rpm has about the same piston speed as a 540 at 8050rpm. You would have to spin a 454 to 10,500 rpm to get the same piston speed as a 632@7200. How many folks do that?

We did get custom pistons made this time and shaved 40+ grams off each one of them, so that will help. He doesn't want it to be a grenade....after this last incident, I don't think he wants to afford any more engine issues.

Now I will wear out a calculator, but I don't believe they solve all the questions. They give me guidelines to compare with "real world" data. Sorta like DCR calculators....neat to play with....but I'm not picking my cam solely based on it. That's why I'm asking here for everyones input.

Keep it coming, this is great stuff! Nick's going to be awful happy when he gets back to a computer and sees all this stuff!


JIM

Now I will wear out a calculator, but I don't believe they solve all the questions. They give me guidelines to compare with "real world" data. Sorta like DCR calculators....neat to play with....but I'm not picking my cam solely based on it. That's why I'm asking here for everyones input.
JIM

EXACTLY!

I'll see if I can dig up last year's rules for you somewhere.

Here's all I can find of last years rules. The official Drag Week rules from 06 have been taken down at the HRM website. I didn't see anything in there about a size limit for BB cars.

UNLIMITED CLASS

*Unlimited is for purpose-built drag cars including any of the following features: full-tube chassis (round or square), Lenco-type transmission, engine setback past the stock firewall location, driver setback past the stock location, quick-release trans tunnels, quick-release front clips, drag-style strut front suspension.

*The interpretation of "full tube chassis" is at the discretion of the Drag Week(TM) staff and is intended to include custom-built drag-race chassis, including those with bits of stock frame retained, or 10.5W-style race cars that retain some stock front suspension. Street rods with street-style aftermarket chassis; Pro Touring, handling-style cars with updated suspension; and some kit cars are not intended for Unlimited, but any car with a fabricated chassis is subject to race-director review and classification. If you need a ruling on your car, send photos and descriptions to HOTROD@primedia.com.

*Engines of all displacements and with or without power adders all run one class.

PRO STREET CLASS

*Pro Street is for cars with tires wider than 11.25 inches or with fabricated suspension that prevents them from running in Street Race, and that have none of the modifications that would place them in Unlimited.

*The following are required: Driver and passenger seats, interiors fully upholstered forward of the wheeltubs, and a windshield of OE-type glass.

*Engines of all displacements and with or without power adders all run one class.

STREET RACE CATEGORY

*Street Race cars that have OEM bodies and frames must use stock or aftermarket bolt-on front and rear suspension. Typical minitub techniques, such as relocating the leaf springs inboard and relocating shock mounting points, are allowed. Stock rear framerails in the stock locations must be retained but may be notched for tire clearance. Weld-in rear-swaybar kits are allowed. Ladder bars and weld-in four-links are not allowed and must run in Pro Street. Pro Touring, handling-style musclecars with Corvette clips, truck-arm rear suspension, or Art Morrison-type G-Machine frames will be considered for Street Race at the discretion of the race director. Some kit cars and street rods with fiberglass bodies and street-style aftermarket chassis may also be classified in Street Race at the race director's discretion. If you need a ruling on your car, send photos and detailed descriptions to HOTROD@primedia.com.

*Street Race cars must use tires on the dragstrip that are no more than 11.25 inches wide at the tread as measured installed and on the ground with a go/no-go gauge. Street radials and drag radials of any size are allowed on the dragstrip.

*The following are required: Driver and passenger seats, fully upholstered interiors, and a windshield of OE-type glass.

*There are four Street Race classes based on engine displacement and induction: Small-Block Naturally Aspirated, Small-Block Power Adder, Big-Block Naturally Aspirated, and Big-Block Power Adder. Naturally Aspirated classes may not use power adders of any kind. Power Adder classes may use nitrous, superchargers, turbochargers, propane injection, or any combination thereof. Small-Block classes are 430 ci and below. Big-Block classes are 431 ci and above, including Mopar Hemis, big-block Chevys, big-block Fords, or FE Fords of any displacement. Winners' engines may be pumped to verify displacement.




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Thanks Eric....maybe he's still in the game!!

You going to run this year?


JIM

I think I may take a year off . . . I've been promising to take my kids on a fishing trip. If the timing works out I will stop in at one of the races though.

I have a $30 calculator because I'm a professional engineer and that's how we roll. BUT just because you can "calculate it" doesn't mean it's meaningful. Most of what is used today was not derived from calculations but rather the painful way - trial and error. Sure, some try to back-calculate to match the empirical numbers LOL but it's much cheaper and more reliable to find someone who has been there done that to save us the trouble. Fact is - we are so far back from the cutting edge we should put our calculators down, shut up and listen.

And ironically the hillbillies who can't read have developed a lot more horsepower that we ever will!

BTW i clicked the link and ironically I have had the reher morrison books for years and have read them several times - very good "no bull" info. Can't say the same (in my opinion) of the V word. I trust the guys building and racing more than I do journalists.

And to answer 454's question about how often you get to redline on the street with a 632: "Every chance I get."

If it wasn't for real world experience in a shop in the mid to late 80's I would not have gained the love and respect I have for this industry nor the basic knowledge of how to make power and machining techniques used to achieve it.
I've worked for 3 mfg in this industry and see if from a whole different light then most. Currently with Stef's we supply most of high end race teams with oiling components and I privledged to see and hear what is going on, what is going right, and what is going wrong out there. I am fortunate enough to me good friends with Kirk Jager of Jager rods and have seen the destruction in these large stroke engines as he works with builders on aluminum rods and piston designs.
So don't take my post as someone who reads the "rags marketing bull$hit" and repost it, my "keyboard" info comes from top people in this industry including company owners and engine builders. So I agree some just need to listen to those who do know.

Al Parker, does that ring a bell to anyone? IA boy. Shop is in the middle of a corn field as described to me and is a converted brick school house. Your right, hillbillys are quiet because they build it and people come. The "full pagers" with their Ad's in the magazine's market power.

I never new Vizard would raise such heated debate. He makes some valid points but his last bit on camshafts and LSA I have no idea where he pulled that from. In the last 12 or 13 years of working with cams for engine builders I have not found his opinion to be true.

Behind these keyboards we don't know who we are dealing with in these threads. Even though I don't own a SF600 anymore, nor run any machinery I can assure you 66 that you will get the straight and narrow with me and no marketing BS.

If I am wrong in that I have taken this as a personal attack based on you felt I was a "magazine engine builder" then I apologize.

Reading right along AND excellent thread!!!!!!!!!!!!!!!!!!

pdq67

I think most of it comes down to what you truly want to do with a car, especially at those power levels. What kind of maintenance schedule and parts replacement program are you willing to deal with?

All parts have a fatigue life to take into account.

Although I'm truly impressed with the HP/CI of a pro-stock motor, a Nascar engine running WOT for 4 hours is very impressive too with their restrictions.


I do agree with one thing, those that know don't talk much and some people with straw hanging out of their mouths can build some power.

Al Parker has built some very stout motors from what I've seen around here...

I think most of it comes down to what you truly want to do with a car, especially at those power levels. What kind of maintenance schedule and parts replacement program are you willing to deal with?

All parts have a fatigue life to take into account.

Although I'm truly impressed with the HP/CI of a pro-stock motor, a Nascar engine running WOT for 4 hours is very impressive too with their restrictions.


I do agree with one thing, those that know don't talk much and some people with straw hanging out of their mouths can build some power.

Doug,
I believe you have a father and 2 sons up the road from you that build some pretty nice BB's that make some real good power and have put some "full page ad builders" on the trailer many a time.

very informative thread.

I don't have any personal experience with these big motors, but the engine shop close to me does. Their building a 648 right now with the new Dart ovals 11 deg heads for a Javlin for NPS racing. They have run many different heads cam combos and do in house dyno testing.

The shop name is Ultratech racing engines in mishawaka, IN 46544. The owner's name is Norm Beerhorst.

No doubt there are some "local boys" who build killer stuff. I find a lot of the big name places tend to aim toward the mainstream and build "safe" stuff, which makes sense....but not if you're doing serious racing. You have to push the envelope a little...otherwise you won't win.

It's funny, they got their reps for building unreal bad boy stuff...then they back off. Of course you make a lot more $$ that way unless you're dealing with the mega dollar stuff.


JIM