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-   -   1971 Buick 455 GS F/SA G/SA Build (https://classracer.com/classforum/showthread.php?t=63449)

HP HUNTER 08-28-2016 10:49 PM

1971 Buick 455 GS F/SA G/SA Build
 
1 Attachment(s)
A few years back I bought a 1971 Buick GS 455 stocker 315/330 HP. After taking delivery of the car I rebuilt the rear suspension, changed the fuel system, rejetted the carb, put on fresh tires and headed for the track. I was surprised when the car ran 11.35 on a 11.85 index (F/SA) on a 2130 foot track with a 27.80 baro in July 4500 DA, although the car was 135 pounds light for F/SA. I put the car away for a few years but couldn't help but think the car had potential if the engine was legal. This last week I got the car out of the garage and pulled the engine and put it on the dyno, then a tear down to determine what I was working with. I will post pictures of my engine build as I go, I will be looking for 30 extra HP out of the engine, if I can get that I will then look very hard at the drive line. I can't help but think if I can get a few hundred more RPM peak out of the engine I can then gear up to a 4.30 gear with more converter. Any advice or information on this build will be appreciated. Dyno test as the engine was pulled from the car.

Glenn Briglio 08-29-2016 07:38 AM

Re: 1971 Buick 455 GS F/SA G/SA Build
 
Got any more dyno pulls with a broader range of rpm? Ie lower and higher.

HP HUNTER 08-29-2016 08:01 AM

Re: 1971 Buick 455 GS F/SA G/SA Build
 
Quote:

Originally Posted by Glenn Briglio (Post 512884)
Got any more dyno pulls with a broader range of rpm? Ie lower and higher.

I do have some tests I started @ 3800 but If I remember right I ran the car from 4200 to 5800 on the track. I really didn't want to run it past 5800 until I went through the engine, after its freshened you can be sure it will be run much higher than 5800, in fact I need more RPM to make the driveline changes I want to make. I do have the top end off the engine now and everything appears to be legal. When I look at whole combination of car and driveline and engine I can't imagine not being able to make it faster. I will mention while testing I leaned the carb down, I had a 67 jet with a .062 rod and it picked up from the race setup and I had no jets or rods to go leaner, I test @ 6400 feet elevation. I will look and see if I printed any of the tests starting @ 3800 RPM, if I have them I will post them.

stage1scott 08-29-2016 09:32 AM

Re: 1971 Buick 455 GS F/SA G/SA Build
 
Subscribed-always nice to see a Buick build. Jason Line still has his world championship GS and at the 4 wides last year (I believe) in C/sa as a 70 he posted some sub 10.50s. Line Performance would be my choice for help with a Buick stocker for sure.

Glenn Briglio 08-29-2016 12:16 PM

Re: 1971 Buick 455 GS F/SA G/SA Build
 
Quote:

Originally Posted by HP HUNTER (Post 512885)
I do have some tests I started @ 3800 but If I remember right I ran the car from 4200 to 5800 on the track. I really didn't want to run it past 5800 until I went through the engine, after its freshened you can be sure it will be run much higher than 5800, in fact I need more RPM to make the driveline changes I want to make. I do have the top end off the engine now and everything appears to be legal. When I look at whole combination of car and driveline and engine I can't imagine not being able to make it faster. I will mention while testing I leaned the carb down, I had a 67 jet with a .062 rod and it picked up from the race setup and I had no jets or rods to go leaner, I test @ 6400 feet elevation. I will look and see if I printed any of the tests starting @ 3800 RPM, if I have them I will post them.

Gear the car where the engine wants not where you want it to run.

Carguy49 08-29-2016 01:20 PM

Re: 1971 Buick 455 GS F/SA G/SA Build
 
What rear end gear is in the car now? You might be surprised how little gear a Buick needs. I know of a 455 Pontiac stocker (same theory as a 455 Buick) that only runs a 4.10 gear and will run in the mid 10's.

Mark Yacavone 08-29-2016 01:51 PM

Re: 1971 Buick 455 GS F/SA G/SA Build
 
Quote:

Originally Posted by Carguy49 (Post 512919)
What rear end gear is in the car now? You might be surprised how little gear a Buick needs. I know of a 455 Pontiac stocker (same theory as a 455 Buick) that only runs a 4.10 gear and will run in the mid 10's.

Ron, The 455 Buick has a much shorter stroke and a bigger piston.
Just sayin'

HP HUNTER 08-29-2016 06:55 PM

Re: 1971 Buick 455 GS F/SA G/SA Build
 
Keep in mind I NEVER get in near sea level conditions. Glenn you've seen the previous dyno data how would run the gear stack? Gear ratio is 4.10 12 bolt.

HP HUNTER 08-29-2016 07:44 PM

Re: 1971 Buick 455 GS F/SA G/SA Build
 
Quote:

Originally Posted by Mark Yacavone (Post 512922)
Ron, The 455 Buick has a much shorter stroke and a bigger piston.
Just sayin'


I agree, in my line of thinking, first I need to get the car out of the hole, more gear, more converter, less internal trans weight, at this point I can deal with the first to second gear drop, but a 1.53 60 not going to get it done, theres lots more there. I believe a 4.10 gear could work in a 29.90 baro but I never see that. So with a 470 CU IN engine with head flow in the 220s @ 28" I think I'am going to concentrate on the heads and intake in that order after the short block is freshened with a modern ring pack.

Dan Fahey 08-29-2016 10:25 PM

Re: 1971 Buick 455 GS F/SA G/SA Build
 
Suggestion.
Check out Dick Millers website regarding your type suspension.

D


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