jmlcolorado
Well-known member
So I picked up an oldsmobile 350 that a guy had built in 1998 but never finished. He let me take the heads off to inspect, let me take the pan off for the same reason. This thing is clean as a whistle. Brand spankin new!
It's got big block aluminum heads on it milled down to shrink the combustion chambers a bit. All his paperwork shows the combustion chambers were 67cc.
Out of my own curiosity, I wanted to check the compression ratio.
I CC'ed the heads to find that they are 67cc. It has 20cc dished pistons (I CC'ed these as well), and with all the numbers plugged in, I have 8.3:1 compression on this engine.
My question is, I know lower compression ratios are better for boost, but I don't plan on forcing air into this right now (due to financial reasons).....
So will 8.3:1 be good enough for a good performing street engine?
I have the engine torn down to the short block right now, so I could opt for flat top pistons and that would take me to 10.1:1. I would just need to check valve clearance to make sure I have the room for flat tops.
It's got big block aluminum heads on it milled down to shrink the combustion chambers a bit. All his paperwork shows the combustion chambers were 67cc.
Out of my own curiosity, I wanted to check the compression ratio.
I CC'ed the heads to find that they are 67cc. It has 20cc dished pistons (I CC'ed these as well), and with all the numbers plugged in, I have 8.3:1 compression on this engine.
My question is, I know lower compression ratios are better for boost, but I don't plan on forcing air into this right now (due to financial reasons).....
So will 8.3:1 be good enough for a good performing street engine?
I have the engine torn down to the short block right now, so I could opt for flat top pistons and that would take me to 10.1:1. I would just need to check valve clearance to make sure I have the room for flat tops.