Well I got word from the machine shop saying it would be best to bore my block because of the run-out from the 135k on it. So i'm going to need to new pistions and i was wondering. Should i raise compression to say 11:1(or maybe higher) or just stay with the stock 10.4:1?
Thanks

 

raise the compression. It wont hurt and it will give you increased power across the ENTIRE RPM range. Thats the good thing about compression, it gives you power everywhere

 

How high could i go on pump gas?

 

buddy ran 11:5 on 93 octane with no detonation or pinging. Ive heard people going higher than that on pump gas, but i dont know them and have never seen proof so take it for what its worth.

 

I'd go around 11:1. A bit higher if you plan on running N2O later on.

 

chit chat with ur machinest bout it.. so r u getn a thinner gasket or getn em milled?

 

Can you up the compression on and LT1 and not have to worry about emissions?...I am getting some LT1 heads port n polished, and LT4 hotcam and this thread made me think , would upping the compression be safe on my block? and if so how far could i take it without having to worry about any problems? and how much difference would that make?

(sorry about all the question and hi-jacking the thread, but i dont know much about compression so im trying to figure all this out)

 

compression wont affect your block and wont have any real significant adverse affects on your emissions. I would upgrade head gaskets to be safe and check PtoV clearances but thats about it on a stock bottom end.

 

I would go higher too!

 

I ran 10.9 for a few years. next motor is going to be 12.0

I bet after measuring your piston to deck and checking every thing you are barely at 10.2. we found my motor to hold a .032 piston to deck and not the normal .025. Check it and see where you are at. then you can go to a Impala gasket (.029 or so) and maybe shave the heads. You may even get Corteco or another custom head gasket a little thinner to get where you want to go.

On the next motor I am going to cut the deck to clean it up and square it. Then we will take measuremnets to have pistons made for what I want toget the piston in the hole. After we assemble the short block I will order head gaskets to get the proper Quench for the most power and 12:1 CR

Good luck

 

again, always talk to ur machinest..

 

Higher CR usually runs cleaner on the emissions end all things being equal