is there a way i can build a sbc 350 to make decent power on regular 87 octane pump gas?
i figure i need to keep compression down, but what about the heads and cam? i would like to make 300-350, is this posssible? it is just a thought. the engine does need to make decent torque down low as it is going in a '59 chevy truck.
There are several things you need to have to figure your static compression ratio.
CC of the heads
CC of the hole in the head gasket. Use the formula V=pi x r squared X H, then convert to CC's.
CC of the unswept area in your cylinder. The area not filled by the piston when it is at top dead center.
CC of the dish in your pistons, if you are running dished pistons.
Add 4 CC's to your total for the flycuts in your pistons if you are running flat tops.
If you plan to run domed pistons, you will need to know what the CC is of the dome, and subrtact that from all the rest of your CC calculations.
Figure out the CC's of one cylinder of your engine, add them all together then divide by the previous computations.
Head gasket= 4.125 bore and .039. = 2.72 CC.
Unswept cylinder volumn is 2.06 CC
Combustion chamger is 64 CC
Piston dish is 12 CC.
Total combustion area displacement is 80.78 CC
Cylinder displacement is 716.54 CC
I am coming up with 9.87:1 compression ratio
You should be able to run your engine safely on 91 or 93 octane gas.
I am pretty sure that 87 would be ok with aluminum heads as long as you get down to around 9:1-9.5:1. Have you looked into AFR heads? I would highly recommend the AFR 180 cc heads for your application. You would make more hp and torque than the unported trick flows, and the AFR's are only $275 more, that is as cheap a port job as you will find.