compression on 350 tbi

[travis mattson]

I have a set 081 casting 305 heads I want to put on a 350 with flat tops, I estimate it will be about 10.8:1 compression. Is there anyone running this set up? Will it run with 92 octane and new chip burn?
The truck is a 1994 chevy TBI 350 with a 262 cam everything else pretty much stock.
Thank you

 

[slowburb]

I calculated 10.3:1.

4 bore
3.48 stroke
0.039 gasket
4.1 gasket bore
-6 flat top
0.025 piston to deck

It just might do it if you can get the tune right. It will want more initial timing and a quick curve.

I suppose the static CR could be higher if the chambers are snaller. Have you measured?

 

[AllThrottleNoBottle]

I calculated 10.3:1.

4 bore
3.48 stroke
0.039 gasket
4.1 gasket bore
-6 flat top
0.025 piston to deck

It just might do it if you can get the tune right. It will want more initial timing and a quick curve.

I suppose the static CR could be higher if the chambers are snaller. Have you measured?

Weren't 305 heads like 58cc? Well, that was what they were back in the day, anyhow. I might be showing my age, though!

 

[slowburb]

It really depends. I've sen some as small as 53. My "601's" cc'd at 53. There are quite a few different castings and chamber profiles.

 

[travis mattson]

CASTING #14101081 58CC

 

[slowburb]

CASTING #14101081 58CC

Actual chamber volume is often different than what's claimed. This is why I asked if you've cc'd them.