Well I'm getting ready to build another circle track car, but I want to do something differet. II've alwas used a chevy, but this time I wanted to try a buick small block just fo kicks. I run in the grandnational division which for those of you who don't know dosen't allow a hole lot of engine mods. I can not build a stroker motor, I'm only allowed a .030 overbore, and I have to run unported factory cylinder heads and two barrel intake. I'm also restricted to stock exahuast manifolds. My questions are for those who really know this engine. I need to know what factory cylinder heads flow the best, and offer the most performance potential. I also need to know which 2 barrel intake flows the best, has to be iron (canadian intake?) I also need to know what factory exahaust manifolds flow the best (can not be center dump.) I'm allowed to upgrade crank as long as it stays stock stroke, and I'm allowed to run aftermarket pistons. I'm limited to 110 112 octane so I try to run no more than 11.8:1 static compresion. Any and all help/info greatly appreciated Alan
Well, I'm not sure on the exact numbers but I'd start with a '68-'70 350 4 barrel engine, then swpa the intake. All were 10.25:1 from the factory. The '70 heads are supposed to have the smallest cc's to give the best compression ratio, but the '68-'69 heads are really close. I haven't heard any of the 2 barrel intakes being better than the others. I'd guess after plugging the heat riser they'll all be pretty close. Same with the exhaust manifolds. I've laid a pair of '69 manifolds next to '72 manifolds and they looked exactly the same. I don't know what cam specs you'll be looking at, but at one point I ran a Lunati H210-220 that was supposed to be one step above stock. Lift was in the .470-.480 range and that cam pulled great right from idle. Not a lot of help, but something to start with.
350 / circle track Alan : i think (???) the exh manifolds that are easily available are about the same , but , and this a strict guess from a quick visual look-see , the pass. side looks like it may flow better than the driver side ??? a little more directional ?? so - can you have room enough for a pass. manifold on the driver side of the car ?? i've thought of that for my 350 but the steering box etc is in the way . just an idea , check your rule book ! Del deadmanscurve@stny.rr.com 607-369-7770
erm. manifolds can't switch sides. to have the bolts line up, one manifold would end up facing foward for, uh, ram-exhaust.
350 forward or backward , its a circle car , flow is flow . run the exh pipe across the front of the engine , back along the right side frame rail where it can meet up with the right side exh pipe and exit out of the car on that side which is where the exhaust exits on the roundy-round cars anyway i guess . Del
68-70 350 motors were NOT all 10.25:1. Only the SP hi compression motors were. But it was because of pistons, and you're upgrading them any way. Heads are basically all the same, with slight variation in combustion chamber size. I don't know much about circle track racing, but don't you want hi-revving motors? The buick is definatly not that. Expecially with stock manifolds and heads. There is a board member here that ports stock exhaust manifolds. I forget his name tho... that's if that is allowed....
Don't forget that 73 and later blocks have the cap screw rods, which I'd want to use in that application for sure! You're changing the pistons anyway, so who cares about the year of the block? 1972 and older intakes will be non EGR. I also like the 68 and 69 blocks because they have the nice 1.6 aluminum rocker arms, but they oil through the head and use "Solid" pushrods without oil holes in the ends.
Greg Gessler ports exhaust manifols....and anything else that you can think of:grin: Info: GeSsler Head Porting Specializing in stock-appearing heads, intakes, and exhaust manifolds for all makes of our cars. 908-362-7692
"dirt"350 / alright a change of pace !! Alan : did you get any feedback on the exh. manifold flow with left/right or different years etc ?? i think that a few years ago i remember reading that the 350 manifolds "didn't flow too bad" but that was about it for info . also - TA now has rod bolts for the older design 350 rods and , according to them a little while ago , they are easier to set up than the newer capscrew design . one of the techs at work used to run a buick 350 , with his son driving , at some local dirt tracks ( 1/8 to 1/4 ) and he made it sound like they did ok . myself and a couple others were talking before about the seemingly (?) easy evolution of the v6 block girdles to match up to the 350 blocks , watch for those for durability . have fun - viva la difference !! Del
