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-   -   HELP,HELP pontiac gurus (https://classracer.com/classforum/showthread.php?t=68067)

Rich Biebel 11-01-2017 10:29 AM

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...

mtkawboy 11-01-2017 03:05 PM

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

Todd Hoven 11-01-2017 06:15 PM

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.

a pontiac 11-01-2017 06:22 PM

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.

Vic Santos 11-05-2017 02:56 PM

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.

HP HUNTER 11-05-2017 03:07 PM

Re: HELP,HELP pontiac gurus
 
Quote:

Originally Posted by Vic Santos (Post 549105)
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.


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?

Vic Santos 11-05-2017 03:38 PM

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.

HP HUNTER 11-05-2017 08:47 PM

Re: HELP,HELP pontiac gurus
 
Quote:

Originally Posted by Vic Santos (Post 549109)
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.

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.

1legjerry 11-06-2017 07:17 PM

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.


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