how to determine compression?

[beaver2489]

What compression do you think I have with the 351 heads being milled .040". My buddy that built my shortblock tells me its around 10:1 or alittle more. I need to get more info on my pistons from him, all he told me is they're lightweight and have valve reliefs

 

[beaver2489]

TTT, anyone think I might have 10:1 ?

 

[MustangPunk302]

http://bbs.hardcore50.com/calc/?mode=enginecompratio

Have fun

 

[beaver2489]

thanks, now I gotta find the bore +.030", stroke, and chamber size of my heads after being milled .040".

 

[Lefty44278]

If you want a ball park number add the displacement per cylinder and the chamber size and divide the sum by the chamber size

you roughly have a 306ci and divide that by 8 cylinders, then you probably have around a 61cc chamber, you then connert cc to ci and then divide that by that chamber volume. The bore is around 4.030 and the stroke 3.00.

so you are looking at around 11:1 - this is with the assumed 306ci and 61cc chamber I can't tell you your chamber size.