HELP,HELP pontiac gurus
 

Want to run a .040 over 400 pontiac72-7500 rpm.

stock 68 400 crank, 63 421 sd reconditioned rods, .040 10:5 trw pistons 68 pontiac 400 heads comp. valve job with 1.65 harlan sharp rockers offenhauser low rise 2 4 bbl. manifold with 2 625 afbs, .600 lift 270 duration flat tappet cam, jackson gear drive, ati balancer, freshened mallory super mag circa 1970, butler valley support. 93 octane pump gas???

will my junk live to 7500 rpm,, have had bbcs,sbcs, 426 hemis, but never a poncho and have not a clue

craig esposito
sagarth.espo@gmail.com

Re: HELP,HELP pontiac gurus
 

All of the Pontiac people/racers I know, talk low rpm torque, not 7500.
Looking forward to other replies.
Good luck with your project.

Mike A114

Re: HELP,HELP pontiac gurus
 

"will my junk live to 7500 rpm"


NO !

Re: HELP,HELP pontiac gurus
 

Heavy pistons , need a better connecting rod . You must have pretty decent heads if you are winging that engine to 7500 . Its possible !

Re: HELP,HELP pontiac gurus
 

Yes, you can build a Pontiac 400 that will do 7500. But the parts you listed will likely not get you there.

I'm thinking a lighter piston, Lighter 326 or 350 crank, Way better intake. A Professional port and valve job. and a roller cam would be nice.

Spinning 7500 and making power at 7500 are 2 different things.

Re: HELP,HELP pontiac gurus
 

What I remember of Pontiac's from when I had one was CAST connecting rods, not Forged. But the SD rods, I don't know. Looks like Scat and Eagle make forged rods for it.

Re: HELP,HELP pontiac gurus
 

The SD rods are forged , but the early ones still had 3/8" bolts , the 73/74 SD rods had 7/16" bolts , most of the aftermarket rods have 7/16" cap screws .

Re: HELP,HELP pontiac gurus
 

What are you guys doing in my garage. :-)

Do NOT even attempt this. It's taken me a long time to find out what works, what lives, and how high of rpm I can go SAFELY.

You tell me the car, the race weight and the ET you'd like. Get that 7500 rpm stuff outa your head. That's not a smart way to approach a project.

And spend $300 bucks on some chinese rods which are way stronger than any factory rod made. I hate it too. (Off shore stuff) But 98% of my customers act like they're dead axx broke, but want the double throw down massive hp. So they get the rod that's very good, and cheap.

Re: HELP,HELP pontiac gurus
 

UGGGH!!! ok so I can not wring this motor where I want to. Bought a set of Molnar rods so maybe it will live @6200-6400 rpm. It is a street car with a pro-shift nash 5 speed but I like shifting at 7000+ rpm ,looks like I will have to learn to shift at 6200. non-tubbed car will be fun trying to hook up this
torque monster using 1972 technology. Extended lakewood slappers and a decent adj. shock, 9 or 10 inch tires. Doing a street-strip car like we had in 1972. Frame connectors but no cage.

Re: HELP,HELP pontiac gurus
 

anybody that wants to b.s. and tell me i'm a moron give me a call

especially bruce fulper

330 831 4480 anytime

Re: HELP,HELP pontiac gurus
 

what rear gear ratio?

Mike A114

Re: HELP,HELP pontiac gurus
 

Odd that some people want to misrepresent helpful replies to a level of hate. ????? I live to help Pontiac guys understand how to get the most from their combination. You don't want my help, fine. Take your hate elsewhere. Long live my 8000 rpm Pontiac.

Re: HELP,HELP pontiac gurus
 

I remember when you told my friend he was over his head on a 1964 389 build. Remember the one where he reconfigured the combustion chambers on the 1964 heads, well it made 502 HP/500 + TQ with 18 inches of vacuum on pump gas, customer was sure blown away.............loves that car!


Bruce, if you know, how hard does Burton turn that ram air 4 in the lights? I would assume its well over 7000.

Re: HELP,HELP pontiac gurus
 

Curious...
How high does he spin the 389?
Thanks, Mike A114

Re: HELP,HELP pontiac gurus
 

That 389 was tested several years ago, and it wasn't tested by me, but I was there but can't remember the peak, I do remember the build because I machined it, low drag, well thought out oil system, a lot of detail work, a well designed engine that ran excellent in the customers GTO and still runs great to this day. Its important to note the customer insisted on using the factory 64 heads with the horrible valve angle. You can be sure it wasn't 7500 RPM.

Re: HELP,HELP pontiac gurus
 

Sorry Bruce Fulper my response was meant to be tongue-in-cheek cuz I truly am a moron where this pontiac motor is concerned I do not have a flipping clue how to make this mess perform properly. I truly appreciate each and every response and hopefully with enough help from class racer this car will run decently and not run over its own crank. My aim is to have fun and run decent. This is the last project I am ever going to do; I am old and physically beat up and really don't want to screw the pooch on this deal.
Again Bruce Fulper I sincerely apologize if you took my comments negatively they were not meant that way and I value your advise and it has opened my eyes to what I have to do make the car work right. THANK YOU

craig esposito

Re: HELP,HELP pontiac gurus
 

P.S. Bruce I asked you to call to pick your brain to keep from making ,more stupid mistakes

craig

Re: HELP,HELP pontiac gurus
 

Jack Mullins 63 Catalina wagon…389/235…4 spd…SS/U circa mid seventies…

http://www.hotrod.com/articles/0212hpp-pontiac-history/

Mullins had what many Pontiac racers might call an aggressive driving style because that is what it took to win. He’d generally leave at 7500 rpm, shifting into Second at 6300, while Third and Fourth were engaged at 6800 rpm. He’d flash through the lights at 7400. “If I was in the final, I’d leave at 8200,” Mullins recalled. At that point I wasn’t worried about going another round. I could pick up 5 or 6 hundredths doing that.” Amazingly, he only had one bottom-end failure. “The crank did come out in three pieces, but that only happened once,” he said.

http://image.highperformancepontiac...._Rear_View.jpg

Re: HELP,HELP pontiac gurus
 

That kind of stuff only works if you are from Arkansas. We are way too backwards and ignorant to make "sofistikated" race car parts work..

Re: HELP,HELP pontiac gurus
 

I've always thought that many Ponco engines had bottom end oiling issues. I would certainly research this area before getting in too deep.

Re: HELP,HELP pontiac gurus
 

Many years ago we had a customer who raced a '69 or '70 GTO Ram Air Stocker
400 manual trans.

It routinely tore up bearings and cranks and we did many of the usual things known to help a Pontiac especially in the bottom end dept.

It also broke driveline parts since the engine made a lot of TQ.

Eventually he put a Turbo-400 in it and I drove it a few times.

I did like that car and it stayed alive a lot better with the automatic trans...

I cannot picture a 389 going over 8000 rpm for many runs back in the era Jack Mullins raced. I saw that car race. The parts availability back then was a long way from what is available today...

Re: HELP,HELP pontiac gurus
 

craiger, I read it and took it the way you intended it, maybe others didnt. You would be a fool to piss off and turn down help from a long time Pontiac racer and Im sure it was not intended that way

Re: HELP,HELP pontiac gurus
 

I doubt the heads will be big enough to make power that high, or the camshaft.
Light pieces in the bottom end. Your oiling system is the downfall of that engine living up there. Light rotating pieces is a start. Then oiling system mods. Good luck, I hurt a few pieces just trying to get mine to live at 7000.

Re: HELP,HELP pontiac gurus
 

If you want to build a replicate a 1972 build expect to run 1972 et 's. A new Pontiac build would include forged crank, good rods {eagle-crower}, light pistons, total seal ring pkg. S/S head porting, 640 or more roller cam and you can see 7500 all day without carrying a broom and dust pan.

Re: HELP,HELP pontiac gurus
 

Craig, your combo will not live at 7500 RPM and will not make any power there. For 7500 RPM you will need much lighter pistons and pins, stronger and lighter rods and a 4340 forged crank that has been internally balanced. You will also need a lot of porting and a bigger manifold and a strengthened and filled block. The stock oil system will also be a problem. You will need high pressure and lots of oil. You will also need a roller cam and rockers and big springs; etc, etc. All of this is needed for high power. The stock block bends at high power and so does the crank. The more power the more problems. RPM KILLS! Pontiacs with stock castings are torque engines and should be designed for it i.e. low rpm.

Re: HELP,HELP pontiac gurus
 

When a B/SA automatic RAM AIR 4 stocker is run, what kind of RPM does it turn through the lights? Or another way to ask the same question, what rear gear do they run?

Re: HELP,HELP pontiac gurus
 

I don't know too much about stockers but I do know that in super stock, 7200 RPM and on a good day 7300 through the eyes.

Re: HELP,HELP pontiac gurus
 

I don't know myself.....but I have a feeling Scott Burton turns over 7000, he told me what gear he runs but I can't remember, but I think its lower than a 4.56. I think he's been 128 MPH, I know for a fact he's been 1.29 60 and that doesn't happen with a 4.10 gear.

Re: HELP,HELP pontiac gurus
 

craiger

I think you got your answer. I would add if this is your last build and you just want to have keep that poncho 400 well under 6500rpm, send it in for a refresh about every 150-200 passes and you should be fine.

O yeh get rid of that offenhauser manifold too.