compression ratio and cam shaft

[canner78]

i have a stock 1974 318 with 8.6 to 1 compression ratio. i am putting on the 302 heads and .024 thick head gasket. what would my compression ratio be when i am done? i have a holley 600 carb, a edelbrock perfomer intake and headers,what size cam should i be running. i want a big enough cam to give that nice lumpy muscle car sound.

 

[rumblefish360]

what size cam should i be running. i want a big enough cam to give that nice lumpy muscle car sound.

You should be running a cam that operates within your cruise range RPM.
When you order the cam, order the valve springs to go with it.

Whats your gear ratio, tire size and tranny type?.
also, whats the intended useage?

After you answer this, I can generalize a cam that would be good to use.
Also, a choppy sounding or lumpy sounding cam is due to the centerline of the cam. So even a small cam can sound big. Big cams can sound small.

 

[C130 Chief]

A stock 74 318 had nowhere near 8.6 compression, more like 8.0. But with the smaller chamber heads, you should have close to 9.0.

As for cam, if you have a basically stock 318 car (3300#, 2.76 gears, 11" converter) I would think an XE 262, or something similar will be reasonable.

 

[canner78]

it is a other wise stock car with a 904 automatic tranny. i really don`t know what the compression ratio of mine is but this is where i got 8.6 from http://www.foundationpc.com/engine.html
and here is another one http://www.mymopar.com/enginespecs.htm
and another one http://www.lhmopars.com/engines.htm

based on this i think it is 8.6 to 1