Just thought I would post some numbers on another set of 350 Buick heads after porting. Theses heads flow 274 cfm on the intake at .500 lift and 197 on the exhaust at .500 lift, at .550 on the exhaust, they flow 203 cfm. Jim Burek P.A.E. ENTERPRISES.
How well did the 350 heads pick up with a well worked bowl, good valve job and just cleaned up port? Did you you have to do much to port itself to get those #'s? Those are some good #'s. It would be good to see more 350 SB guys join the speed game. I think with good flowing cylinder heads they should be able to post some good #'s. I'm ready to see some 9 and 10 sec 350 Regals and GS's. With a power adder and a good combination, its not far off. The question is, Who's Going To Step Up To The Plate?
Rick, these heads take quite a bit of work to get this much air flow out of them. Let's just say it takes lots of bowl work. The ports are not opened up much, gasket matching and some work around the head bolt boss. Jim Burek
I had my stock 350 heads have a pocket port job, with a competition valve job and backcut valves, I picked up a 13% increase in air flow over stock. These are the numbers at .500 lift Intake before 188, after 206 exhaust before 137, after 152. I didn't do any port matching, I have not put the engine together yetso would it be worth it to port match my exhaust? Tim
Very nice Jim. We've been working on a few sets here and were able to get 292/214 @ .500. But this was with pretty extensive port work. On a Superflowmaster at 28". I would really really like to see a 300 but I think we might pop a few holes trying to get there. PS. Our little procharger projects both tore themselves apart. But on a good note, we did see mid 7's hp at 15 lbs. with the sbb before it went over the crank and rods at 6800 rpm. If at first you don't succeed.............o No:
jim, are they coming to me gift wrapped? cant wait to get the motor together and warm up the driveway..lol john
Now that's some pretty impressive power from a motor that aint supposed to run. Amazing what a littel boost can do eh? Let's see, 15 pounds of boost, that would be like a 700 inch motor wrapped in a 350 inch package. Jim Burek
jim, it will be certainly interesting to watch my son's face when he drives it. bill, tell me more about those chargers......... we are only a few hours away. john
Hey Bill, If you don't mind me asking what was the specs on your 350 build up? Did you just hurt the rods and that messed up the crank? Was it a oil problem/ spun bearing that ate it? Crank break? Do you think you could adjust the combination to get it to live at mid 7 #'s?
Rick, The build was close to a copy of the one J.B. did for Rob (TuBBed). We did find a set of TRW forged pistons (inverted dome) that put it at 8.5:1. They were Pontiac pistons so I believe there were adjustments necessary ( pins & crank). We had stock '70 rods so that may have been part of the problem. Solid cam 245/253 @ .050 Intake was a stg. 1 with the divider cut 3/4". Now the wild stuff: We fabbed a 5" spacer between the carb and manifold. (750 Holley) All the duct from the D1 procharger to the carb hat used long radius 90* elbows rather than short radius to help reduce turbulence. Oil was not the problem as the bearings were fine. We bent 4 rods, broke 2 others, and bent the crank. We are thinking it was the cam. Will know more after some more examining. With the numbers that J.B. made with a n/a engine I really believe these little engines could put their bowtie cousins to shame. With the right parts and setup, a boosted 350 should be able to push 750 - 800 hp and remain healthy. We'll see! What do you think? Any thoughts?
Bill, I suspect the rods could not take it. The earlier rods definately are not as good as the later ones and of course we used really light pistons, which helps. But your set-up sounds very interesting there. Just need some stronger internal components in that thing. Jim Burek
Well, I got some thoughts...... Those TRW's are usually pretty heavy pistons that are alot more stress to a stock rod at rpm. If you stick with a stock rod and want to make power, definitely spend the money on a decent piston. I know your cam is wrong for more than 6-7 lbs of boost. You could have had problems just because you had the wrong cam. With nitrous motors, if you push more nitrous than the cam and airflow requirements allow, they will come apart. You could be wasting ALOT of Hp by not having enough exhaust duration/added flow. You can get away with the wrong lobe centers but not with duration and/or flow. Your motor could have been working at an 800+ Hp pase but only putting out 750. The load is there the #'s aren't. Since you have to get another cam, try about 7 more degrees on the exhaust and keep the LC about 114. If the LC makes it too lazy than drop the intake duration to 238-235. You can get away with more compression if the cams big enough. What LC's were you running on your cam. WHat centerline did you install the cam at.
Rick, We kinda knew this engine would self destruct. First time on the dyno it lifted the heads at about 6300 rpm. Didn't even damage the gaskets! Boost was almost 16#. We had a feeling the cam was short on the exhaust. LC was 109*, set 2* advanced. There is a long story regarding this whole scenario. A few months ago when Jim posted the dyno results for Rob's build I took the numbers to a friend of 35 years who is a very successful builder and racer of Chevy engines. He was pretty impressed with the numbers produced from what he called a "low mod" n/a setup. I asked why he never gave the Buick engines a second look and he said because the bbb had too many weak spots and just never gave the small block a second thought. After a little prodding and a good amount of grovelling he agreed to check one out to see what kind of potential it had. I rounded up whatever "go fast" parts I could find quickly so we could do this little experiment. Originally, we only planned on maybe 8-10 lbs. boost max but we didn't want to wait for the pulleys from ATI and went with what he had - hence the 16 lbs. Now the really great part about this is it only cost me a grand total of $470. And the even better part is that it peaked his interest. He already has another crank, a set of capscrew rods, and is talking of having pistons made. And yes, I'm sure he'll put the right cam for the setup in it this time. More to come............. :3gears:
Hey Jim, Are the flow number that you have gotten with these heads, and also the heads one the engine you built for Rob, normal. Or are they more of the exceptions rather than the means. Just wondering what are the chances of getting repeated results like these from my heads.
They are repeatable. Robs heads were the first we really di some serious porting on. I just finished another set that out did Robs on the exhaust side. There just have'nt been many people looking to really push the 350 Buick's. But there is some really good potential there. Jim Burek
350 heads Jim Don't know if you remember me:laugh: ..but you did a set of 350 heads for me on 6/9/00...I still have the flow chart you sent with the heads:TU: ....intake was 246CFM at .500 lift and exhaust was 168CFM at .500 lift...on the bottom of the page you wrote" exhaust to intake ratio 68%...and 246 cfm is capable of making "467 Horsepower"...you also set me up with a Comp cam #270H.. and a set of adjustable push rods for my 70 GS 350...I never really did any serious racing with the car ( YET )...but it sure does run well:grin: ... Just thought people would like to know how far back that you did some serious head work on the LITTLE 350 Buick motor...:beer .
