1971 Buick 455 GS F/SA G/SA Build
 

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.

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.

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

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.

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.

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

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

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.

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

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

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.

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

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.

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

Suggestion.
Check out Dick Millers website regarding your type suspension.

D

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

Thanks!

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

Just throwing this out there...I see you're testing at 600rpm per sec (which is standard) did you (or would you consider) dynoing at 300rpm/sec? The reason I ask is it has a heavy rotating assembly and a super steep gear might actually slow it down as too much torque wasted spinning up the heavy internals?

Like I said, just throwing it out there....food for thought as it were.

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

I did test at 300 RPM/sec, not much difference in power output. The fast F/SA Buicks 315/330 HP run a 4.30 gear and turn 6600 RPM in the lights, and run 10.80s @ 450 elevation. Its important to note the 315/330 is a whole different animal than Jason Lines C/SA combination.

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

In stock your not suppose to be able to do anything to the heads and intake besides a valve job right? although judging from your other post and that you seem to have a in house dyno and who knows what other equipment your probably perfectly capable of altering that to your advantage.

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

Jason Line 70 Buick Gran Sort 10:45 in C/SA at Indy this week!

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

Jason Line qualified 60/128 at -0.950 under his 11.40 Index

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

and your questioning his integrity why?...........

Different valve angles and seat width effect flow, and that's just as two examples of what he meant by "work on the heads". There are many more legal things to do before resorting to "port the heads and cover it up" as you're insinuating.

Uncalled for imho, there are a lot of people with a lot of equipment, doesn't mean they must be cheating because they have fancy tools.

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

Thanks, but I took no offense and never thought anything about it. I asked people for their opinions and really want to here them. I will say this, this forum going to see everything I do to this car-from start to finish, all the engine work including head work-to the dyno testing to the in car testing, I've never seen anything this complete on here before, should be interesting.

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

How would your intake valve job look like on a .398 lift? Anyone.........

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

Just wondering where you got the car? I ran the same combo in the past I have a good set of 71 heads TA SS valves with Poston springs off the car along with a few other parts. I am located in Texas now formally Va.

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

Been there done that, it is good street car stuff.

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

A few years back I bought the car from a gentlemen in Wisconsin, he bought the car from Lyn Smith. I'am looking for virgin 661 and 149 casting heads, not easy to come by and 403 intakes.

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

OOPS. I actually didn't mean to insinuate he was cheating just a poorly stated question.

the correct question you answered though(thank you) basicly should've stated how much and what can you do with in the confines of a valve job to find gain, and the statement about the tools was just meant to mean he seams to have the tools at his disposal to play with valve jobs and test effects,and if i'm correct from his other post hp hunter also really seams to know what he's doing when it comes to building engines and making power, so i tend to watch his post there normally interesting.

the other part of this i find interesting is that i've read that low lift flow isn't always a good thing do to the possibility of reverse flow during the overlap period or stopping intake flow too soon. but in a stocker with a .390 ish lift limitation low lift is all you have so i guess you get all you can.

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

25* seat angle on intake with a narrow .070 seat because of so little lift.
20 top/25 seat/45 below and 70 in the throat. Make the 20 plenty big(not to the point of unshouding, lol) then deck to bring back cc's.
Instead of a 30* backcut on the valve(normal with a 45 seat), with a 25 seat, cut back 15-20* instead, basically anything to break the edge.
This works on sbf, not sure of the chamber clearance on a BBC or Pontiac/Buick etc.
HP Hunter, is this the type of answer you're looking for?

pfordamx, low lift is always good as the valve goes past it twice and more time is spent at that point then at the peak which most seem to focus on. I've never heard of (better or more) low lift not being a good thing, ever, but I'm willing to listen/learn from others...with validation and testing of course.

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

i have no independent testing to back that up i've just read the discussion quite a bit on speedtalk but more ways to prevent the port from flowing in reverse then limiting low lift flow but consequently i would think those two things would almost come hand in hand.

and HP hunter i really didn't intend any offense i enjoy your post.

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

I have a set of virgin 149 heads make me an offer

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

Please send me your phone number, thanks.

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

There was never any offense taken;)

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

This is something I can sink my teeth in.........I will give it a try on my test head..........thanks.




"pfordamx, low lift is always good as the valve goes past it twice and more time is spent at that point then at the peak which most seem to focus on. I've never heard of (better or more) low lift not being a good thing, ever, but I'm willing to listen/learn from others...with validation and testing of course"


But at the same time you have to consider where the piston is..................

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

Some very important tooling showed up today!

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

Nice!
You don't scrimp on tooling do you! lol

Like they say, if you're gonna do it, do it right.

I too love following your threads.

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

I really didn't see any other way, considering how many times those heads will be on and off the bench, repeatability will be very important, I should have some as run flow numbers soon.

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

Can't wait, I can imagine some must be concerned with you showing "secrets" lol!

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

Not sure about that. Heres the flow numbers on my stock 661 casting heads.

Intake flowed @ 28 inches 4.350 bore SF 600 bench

.200 120
.300 177
.400 207

Exhaust flowed @ 28 inches 4.350 bore SF 600 bench no pipe

.200 95
.300 124
.400 143
.460 149

As you can see I've got a real power maker here.............

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

Where are the flow figures for .100 lift? Are these the heads off the car that have a "normal" 3 angle valve job or untouched as produced at the factory? As my post a few years ago mentioned I improved my low lift flow substantially at the expense of a small amount of loss at .400 lift. This helped my car measurably. Since that time i have done more experimenting with valve jobs, back cuts, etc. with surprising results. The oem valve seat is 45 degrees, right? I would try a 37 degree and lots of experimenting with "different" types of valves. Oh yeah, make sure the heads are cut close to minimum cc's before anything is done (saves surprises later). Ron.

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

Great information, thanks, I will look for your thread.

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

Yes pay attention at low and mid lifts!!!!

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

Maybe I'm missing something here. I thought valve seat angles had to be within 1 degree of the factory angle.
Pete

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

That 1 degree refers to the valve inclination angle (I.e. the angle of the valve stem in the guide), not the valve seat angle. Any valve job is permitted as of (I think) 2009 in stock eliminator. Ron.

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

Thanks. That changes my line of thinking.
Pete