Ive been going threw some stickies and I'm fairly sure this question hasn't been asked. I have basically a stock 305 with a fairly large camshaft. I have been running a 160 thermostat. I do make my own chips and have all the temps to work with the 160. I got the camaro (1988) stock with tbi. Then it had 185 PSI cylinder pressure. Now with the camshaft, i now have 150 PSI. I am wondering if i would benefit from the 195 having lower cylinder pressure. I would think cylinder temps would be lower with the lower PSI. I'm sure someone has done this before. I installed a new intake manifold today and i have both thermostats sitting here ready to go on. Thanks.

 

Im leaning twards the 195 since my cylinder pressure is lower. I wasnt getting spark knock @ 50 degrees timming before.

 

This is more of a "Theory of combustion" question. Does block temperature affect cylinder temperature?

 

What id like to do is raise chamber temps so i can run less spark lead. I really don't think 200 degrees is really all that hot for a block. I think the "performance" chips that require the 160 thermostat run a tad more timing. All i think the colder temp is for spark knock (and these stock tbi motors really like to spark knock). Since i have an engine tune that is at the other end of the spectrum (wont spark knock if it had to with wicked spark advance) may benefit from a warmer block. Think of it as an entirely stock 305 tbi and replacing the heads with corvette aluminums, alot of timing would have to be added there to get the cylinder temps where they need be (just look at an 87 IROC bin compared to a 87 corvette bin). If anyone has any ideas, would help.

 

Eh screw it, im the kind of guy who jumps in head first and heads for the surface. I stuck a 180 Themostat in there. I figure the chamber/piston area really doesnt care about the ouside block temperature. Ill just continue with the amount of lead i have now. The single plane manifold i just installed threw my bin a curve. Gonna have to start retuning the thing because my #50 injectors think they are #90 now. So much for bigger injectors are raising fuel pressure. thanks anyway.