QUOTE(Bruce Hinds @ Jul 5 2014, 08:40 AM)
Dunc,
Basically there were three common size crankshafts in the SBC series, other than the 400. I get mixed up on the 305 and 307. But torque being a product of stroke the 283 and 302 used a 3" stroke crank. The 327 and the 307(?) used a crank about 3 1/4" and the 305 and 350 used the most popular 3.48" stroke crank.
283 and 302 engines need to really rev to get the power out and then you get into the heavy duty valve train components, screw in studs, roller rockers and heavy springs. Everyday driving usually doesn't see those kind of revs(above 5500-6000) so you may not end up using the power after all.
I chose to use a bored 327(331) and controlling the low end torque with the cam, heads and exhaust. Here again, the big heads with 2.02 intake are probably great for making high RPM power, but everyday hot rodding the more popular 1.92 intakes will produce more even mind range power.
A lot of guys use the short tube headers too, they're great for making torque and creative exhaust set ups, but longer tube headers are better for the mid and upper range power and not having a crossover helps too. Without a crossover you'll have to work on pipe size to help quell the resonance.
Hope this helps.
Thanks for your email Bruce. I am located on the east side, but occasionally I make it over to Kitsap County. Maybe we can chat over coffee some day.
From my reading, the 302 is a 4" bore with a 3" stroke...i.e. a 327 block with a 283 crank in it. What interests me about the motor is that Chevy specifically intended it to be a road racing motor...with a fairly broad power band. Not a motor for the Saturday nite drags. I have read that a modern 302 build uses roller lifters and roller rockers---the entire valve train, as you point out, must be very light weight to function at high RPM. In any event, I want to do a build that is balanced...motor, transmission, axles, brakes.
Thanks for your help.