1021 hp from Buick 350, ran 8s in the quarter

[Sean Buick 76]

**This is old news to many people however I just recieved the permission from Bill to re-post this info**

For a 350 Buick this is pretty impressive considering the lack of aftermarket parts. The entire rotating assembly was all custom order. No aftermarket heads and only 1 aluminum intake equal to a Edelbrock Performer.

Motor Breakdown:
350 buick stock 2 bolt main block 3.830 bore x 3.85 stroke (stock configuration) All ARP Studs throughout-60-80psi oil pressure running 50w Redline stock oil pump.
Custom crank, Custom rods, custom forged Pistons 8.5 comp
Custom Roller Cam-246/260@.50 .578/.600 112LC installed straight up.
850 CSU Carb and Hat 80/88 jetting on final pull
Aeromotive A1000 regulator
Race air-to-air intercooler w/ a 125 mph fresh air fan in front.
Headers are 2" tubes - 21" long - 4-2-1 merge into 3.5" x 4.5" megaphone 5" long.
Port IRON BUICK HEADS 290intake/200exhaust 1.6 Roller Rockers
Cometic gaskets
Ported STOCK IRON 4BBL INTAKE with plenium milled out
5" carb spacer

2 different ATI superchargers were used:
D1 Procharger
F-1 Procharger- Chevy cog adaption. Drive: 8" & 6.75" Blower: 3.5" down to 2" in 1/4" increments. 8" and 3" were the most used up to 16psi.

Motor, N/A Hp and torque numbers were mid 5's NA and the graph pretty much went flat just over 5800.

First Combination D-1:
838.5 hp @ 7100
674 tq @ 6000
12 psi.

Boost to 15psi (overspinning blower)
881.1hp @ 6950
711.1tqe @ 6105

Second combination F-1C:

950 hp/ 731 trq. Ran it up to 7200rpm on PUMP GAS!! 20psi
upper 900's with more tuning on following pulls......

on the seventh and final pull w/race gas and 20psi:
1021 hp @ 6800
808 ft. lbs. trq. @ 5750!!!

After watching a video of the monster 350 this was the posting:

That 350 was singing quite a pretty tune. Sounds like she was quite a ways past 6000

I must also commend you on you mid 5 HP numbers. THats a pretty impressive for the "little" 350 with low compression. Basically a pump gas motor without a blower. I'm sure it's out of the normal guys budget with the high dollar bottom end. Stock or New fordged crank?

I hope the exhaust can keep up with the blower on it. Anything new and special on the exhaust side? You must have a pretty decent cam and valvetrain to get 7500+ out of it. Are you running a blow thru carb setup? I figured the small carb/throttle body used for the blower was why it leveled off at 5800. The motor sounds real strong, I'm sure your going for at least 850HP+ with this one. I'm rooting for that 350 of yours.

What kind of oil pressure did you run on your dyno pulls?
I know it doesn't need as much with the smaller bearing journals but curious what you ran.

What type/weight oil?

What air bleeds and jetting did you run for the 3 different pulls? Did you have to do any additional internal mods?

What blower hat did you use?

Which carb worked best the TPC or the CSU?

What fuel pressure regulator did you use and where did you take the boost reference for it form? Did it hold 1 for 1 on the boost to fuel pressure?

Cog drive or rib belt? I figured cog for 20 psi.....But what pulley size did you have to run to get the psi out of it on the three combinations??

Chevy bolt pattern on the balancer?

Was there any "chatter" marks between the main caps and the block??

What roller rockers and ratio did you use?- I'm assuming 1.6...

Any chance of trying less compression on the next motor or maybe even more??? +/- 1/2 point?

What did the timing chart look like? Total and how much out per psi?

On the girdle subject. I would think a girdle on the same concept as the one used for the 455 is all that is needed. Billet Caps and side bolts would just be extra uneeded work. Unless a simpler "under-pan" halo style girdle is used. THen the side bolts and maybe billet caps. I support anything that help keep it together longer.

Any hard block for the "next Time"?

Glad to hear the Cometic gaskets held up with the 4 head bolts an 20 psi!! Any signs of lifting?

Wow Rick you must be buzzin'!!!
On the pulls we ran between 60-80 lbs pressure.
Redline 50
We used a CSU hat and ended up using the CSU Demon. The TPC
Air bleeds and jets were changed so many times I couln't tell you what was used when. I believe the last two pulls were 80/88.
Aeromotive A1000 with a Product Engineering boost referenced reg.
First taken at the hat and then moved to manifold pressure.
Yup! Rockers at 1.6
Yup! Chevy cog adaption. Drive: 8" & 6.75" Blower: 3.5" down to 2" in 1/4" increments. 8" and 3" were the most used up to 16psi.
The cometics held very well and have been reused several times now.
We had them made after we lifted the heads on engine #1. We also went to studs.
Billet caps were programed and ready to be made. We were waiting to see if we had to provide for the girdle. Yes we will.
The girdle will be just like the big blocks just a lighter version.
No side bolts, no four bolt mains - can't be done.
No fill yet.

Go over the numbers and make some adjustments to fuel rate and carb. Ready for pull #2.
Second pull is much more impressive. 950 hp/ 731 trq. Ran it up to 7200rpm. Boost rises much quicker with the F1. Engine has a different "sound" than with the D1. Almost like a lower roar is how I would describe it.
Everyone is very excited. Great numbers for a small block and it seems like it handles it well. Let's analyze the data!(Oh S^*T) This is when I take a quick run home to call my parents in Florida. Mom just had hip replacement surgery. She's doing incredibly well.
Upon my return I find the swarm in the dyno cell just finishing the latest round of changes and adjustments. Ready for the next round!
Now this scenario was repeated three more times and the results were pretty much the same. Hp numbers in the very high 9's in the 65-6900 rpm range but above that the curve goes flat and actually drops a bit. Even though the boost kept rising it couldn't make more power. Let's go over the data again!! (OMFG!)
They come to the conclusion that the manifold and heads are inadequate to handle the volume of air and fuel needed to make more power. (Duh!!) We were at our max. They are very impressed with the results though.
They wonder why the sbb hasn't been "looked at" for all these years and make some chevy comments and comparisons that didn't sit well with me. But that was OK, I was a little bummed because we hadn't reached the 1k number I so desperately wanted. This is when I see “the builder” with a s^*teatin’ grin on his face.
He gives me this nose wrinkle thing he does and then make the statement: “ Really wasn’t bad for a pump gas motor!” (Open mouthed silence) “Let’s try one with race gas!”
We did the pull, got the 1021 hp number and I was able to do the endzone dance in the control room. Was congratulated by the guests and even got a hug from “the builder”. He was happier than a pig in poop!
So now the guests and all the data will go back to the west coast where it will be looked at and dicussed.
Hopefully something will develop from this that will benefit our hobby.
I’m very pleased and satisfied with the outcome plus I get to rub “the builders” nose in it for awhile. He on the other hand is very happy with the outcome but is not satisfied. He wants to push farther!!!
(I was kinda hoping for that.)



We measured each rod during the initial assembly and after the teardown.
Pistons, pins, big and small ends, and beams. Lifters and bores were checked.
Cylinder bores and walls. Crank and journals. Cam, bearings, gears, oil pump, timing cover, distributor, and fuel pump. Heads, rockers and shafts, springs and valves. We checked every dang internal piece of this puppy!
We aren't making any changes to the setup until after the next session.
We may fab some kind of halo for the bottom if we need it. Talked about billet caps with extra bolts too. We already have a second set of MLS gaskets if we pop the first set.$$$$$
I mentioned to you in a previous thread that we were only going to 20 psi max. Well, now that number has risen to 24 psi. He figures 1 1/2 atmospheres will bring in about 150% hp increase over baseline. That would translate somewhere in the mid to high 1200's. I'm a little anxious now because we are entering the detonation danger zone. Make ready the alky plate!
No dyno this weekend and never on Sunday!!!

Everything on the bottom is new.
Custom forged crank ('cause nobody make them).
Custom forged rods ('cause nobody make them).
Custom forged pistons ('cause nobody makes them).
Custom ground cam - because we had to.
In fact everything internal is just about special order because nobody make them. We even had the head gaskets made special order because they don't make them for 350 Buick. Yes, lots of $$$$$$ here but I think it's gonna be worth the outlay when the final results are obtained.



I'll feed you a little more info.
Custom - 4340 forged - 45 lbs. - special order - only cost 1k. You will most likely pay twice that price.

Forged Pistons dished 8.5:1 - 540 gms. - $700. You'll pay a little more.

cam custom grind roller - I think it was around $300.

There is much more that went into this like the heads with roller rockers and the machine work and balancing. Big $$$$!

CUSTOM RODS $1040. Stock specs.

The carb we used during the n/a pulls was a 850 Demon. Worked very well ya think? The other will be a 750 TPC blowthrough carb. under the hat.

The cam is a roller - 246/260@.50 .578/.600 112LC installed straight up.
What are your feelings on this?

Head porting info:

Being one of the resident experts at blowing holes in these heads I had to throw in my .02.
You already know that head is a doorstop now so lets look forward.
Find another set or two (you'll soon realize why) and have them checked for cracks and cleaned up well.
Now you do your port and polish work.
Port match to your manifold first removing the minimum amount of material from the runner floors to make the match.
The sides of the runners only need to be opened at the mating surface and smoothed toward the bowl area. Not much material removed - just smooth.
The runner roof can be tapered from the port match to the bowl area. Good amount of material removal.
Now you move to the bowl area. This is where the magic happens. From the transition of the runner roof you will be grinding the guide boss as flat as you can.
You can remove material from the entire bowl area and make smooth.
Smooth the short turn radius without too much material removal.
That takes care of the intakes. Smooth but do not polish.
On the exhaust it is pretty much the same but you want to polish everything as best you can.
Do Not remove much from the exhaust runners. Concentrate on the bowl area.
Now the bad news. 350 heads that are over ported tend to crack between the two inner intake ports so it is a good idea to have spares just in case

[Sean Buick 76]

Hopefully my Lark will put these numbers to shame...

[gsjohnny]

better break out the BIG check book, your going to need it.

[J rock]

Hopefully my Lark will put these numbers to shame...

Ya and hopefully I will win the lottery.