My Buick 315 HP 455 G/SA F/SA Build

[vortecpro]

Years back I bought a 1971 Buick GS stocker. I did some suspension work and replaced the fuel system and loaded up my Q-Jet parts and headed for the track, Kearney dragway 2130 feet elevation, I really didn't know what to expect because out in front of my shop 6400 feet, it didn't feel very fast, but I figured we would have fun bracket racing over the weekend any way. So...I roll into Kearney (5000 DA ) and break out the Q-Jet box and tune my way to a 11.35 @ 115.98 (F/SA index 11.85) I'm thinking this ain't to bad and besides I really like the car. That night in the motel I'm wondering how light this thing is, (3635 for F/SA), from what I could see I'm 5 tenths under the index in 5000 DA conditions with very blackened oil. So I devise this plan to go through the engine and see how far under this thing will go, and of course I know nothing about Buicks, but that didn't stop me LOL. So I get back and pull the worn out engine and put it on the dyno, dyno test below. I then disassemble the engine and make my plans. I freshened the very tired short block, changed some clearances, tightened some clearances and put it back together the best I could with the parts I had to work with. I got to the heads.....which sport a 2.005 intake valve along with a 1.630 exhaust valve, I hot tanked them and got them on the flow bench as fast as I could. In my shop we have a saying, on an engine like this "it always comes down to flow through the intake tract". Well heres the sad truth Buick fans, when comparing HP potential to other production engines, my flow as raced was:

SF 600 4.350 bore, tested @ 28 inches
Intake
.200 132
.300 185
.400 211.7

Exhaust
.200 95
.300 124
.400 143
.466 149

So as you can see, not much flow, but I was happy knowing this could be improved. And the hyd cam lift is .398 Intake and .466 Exhaust. I will post some pictures of the short block along with the new cylinder heads. Observed or Measured or uncorrected HP was 343 HP @ 6400 feet elevation.

Specifications:

4.340 bore
3.912 stroke
28.7 CC Venolia NHRA legal replacement pistons, 5/64 rings -.010 in the hole
Production Buick 455 rods
10.69 actual compression
.398/.466 hyd cam, unknown duration
2.005/1.630 valves, no porting, 59.5 cc 149 castings
Stamped factory rocker arms
403 factory cast iron intake
Factory 1971 Q-Jet carb
Factory oil pan

[1989TransAm]

I think those are darn good times all things considered.

[vortecpro]

I think those are darn good times all things considered.

Thanks, I thought so too, it made wonder the possibilities.

[cgarb]

My 350 Buick used to run pretty good for what it was. My fastest time was a 12.01 at 109. All factory parts except for the cam and rockers. Pistons were flat tops out of a v6 engine. I just wish their oiling system was not so stupid. I would probably still be running one if it weren't for that.

[vortecpro]

Pictures of my very rough short block freshen up.

[In-Tech]

Hi Mark,
Very nice car. I am confused though...is that dyno sheet when it was stock and worn out? It is dated 2002. If I read your post right, you ran low 11's when it was stock and worn out yet tuned. Have you been back to the track in Kearney since the rebuild? Not sure where you are in CO now but I used to live in Wauneta, NE when I was a kid and got the chevelle/el camino BBC bug

[vortecpro]

Hi Mark,
Very nice car. I am confused though...is that dyno sheet when it was stock and worn out? It is dated 2002. If I read your post right, you ran low 11's when it was stock and worn out yet tuned. Have you been back to the track in Kearney since the rebuild? Not sure where you are in CO now but I used to live in Wauneta, NE when I was a kid and got the chevelle/el camino BBC bug

Any time I post a dyno sheet/data pay no attention to the date its never been set, and I believe it goes back to a default setting. The dyno test you see above was from the Buick as I bought the car with the engine tired as it ran 11.35 @ 115.98 in Kearney, the base line before any work was started on the engine. I should mention, I believe when I dyno tested the engine it was in a better state of tune on the dyno than when it ran 115.98 MPH just because its easier to tune on the dyno than in the car, the timing marks were hard to read, the electric water pump drive was in the way, a bad setup from the previous owner, on the dyno, timing changes and carb changes are a snap. Since now the short block has been rebuilt I've fixed the readability on the timing marks in relationship to the water pump drive. The happy dyno shows 474 corrected HP @ 29.92 60 degrees dry air, 343 measured/observed HP, track performance shows 426 observed HP in a 27.80 baro 5000 DA interestingly enough. I do think as the engine was tuned on the dyno it would have run 11.2s @ Kearney. I guess I should mention I'm definitely looking for 10s with the engine freshened in the same 5000 feet DA, stay tuned cause its almost done, then its going to be testing time. Hope this clears everything up.

[vortecpro]

Some pictures of the heads and parts that are going in the heads. All 211.7 CFM @ .400 lift. So lets put this kind of flow into perspective and compare the Buick head to a couple of popular BBC production oval port heads.

390 1967 closed chamber 2.190 intake valve zero porting 251 CFM @ .400 lift
781 1974 open chamber 2.190 intake valve zero porting 263 cfm @ .400 lift

Not a totally fair comparisome but a bigger intake valve will never get the 149 casting Buick head in that range with out porting. I should mention Buick expert Chris Skaling helped me through this Buick rebuild with his very solid advice.

[tenxal]

Following your thread on Class Racer Forum as well.

Fellow Div. 5 racer Jamie Picht has been making good progress with his similar Buick. Good combo, love the bore/stroke situation as compared to the Pontiacs.

[pamotorman]

My 350 Buick used to run pretty good for what it was. My fastest time was a 12.01 at 109. All factory parts except for the cam and rockers. Pistons were flat tops out of a v6 engine. I just wish their oiling system was not so stupid. I would probably still be running one if it weren't for that.

on buicks I used a remote oil filter adapter with 2 outlets and ran one feed into the rear of the main oil gallery and the other into the oil filter location. these were 455 but I would guess the 350 is the same.

[steve316]

Thanks for posting; nice build I'm a chevy fan but I am always happy to read about other builds. Who ever keeps your shop clean needs a pay raise.

[Casper393W]

I love this. It just goes to show how much can be done with so little!

[vortecpro]

Some more pictures of the valve guides going in.

[cgarb]

Did you make sure you got an extra good cleanup when facing those guides off down in the ports?

[vortecpro]

Did you make sure you got an extra good cleanup when facing those guides off down in the ports?

Well there was a nick in one hole and I figured I need to make them all the same After installing the guides a honing them to size the valve job started, of course there was one seat that was low so I installed one intake seat.