[Nosbaby]

I am getting ready to change things up in my small block chevy, my question is
what are all the big hitters doing for compression ratios?
I have heard a while back that their lowering the compression allowing more nitrous into the cylinder. but lately I have been hearing of them running higher compression like 14-14.5:1?

motor is a 12* sbc, compression now is 13.5:1
im gonna bore the block out some and order new pistons, what should I go with? and the reasoning for it?

thanks

 

[The Joker]

13 will be good

 

[576 stroker]

Well , i don't think compression ratio is the issue here , more like quench or in another term lack of..................nitrous motors are touchy regards tight quench , also got to be on top of the game as the tuning window is small , on a nitrous motor i shoot for around .070/.100" piston to head clearance , just my 02.

 

[Induction-Solutions]

Nosbaby,
It looks like 576 hit the nail on the head. The compression number is only a part of the equation, the quench area, dome size/configuration, chamber shape and size and so on are the important parts.. Thanks, SJ

 

[Nosbaby]

ok thanks for the input. I will have to check with my machine shop on that stuff.

I know the chamber size is 46cc's and the shape I have been told is just like a SB2-2 head. pistons will either be a 10cc dish or a flat top.
not sure about the quench area.

thanks

 

[Nosbaby]

ok I asked a buddy of mine about the quench area, he tried to explain it to me.
it sounds like the area between the piston and the combustion chamber. and he mentioned that for nitrous you want a larger quench area? so should I have my combustion chambers reworked?

 

[409stang]

take a look at this thread, http://www.yellowbullet.com/forum/showthread.php?t=307207&page=5
you can soften up the chamber and sink the piston down to help with those heads

 

[Nosbaby]

very good info^ there. I may have to send my heads out to get the chambers reworked then.

 

[Induction-Solutions]

ok I asked a buddy of mine about the quench area, he tried to explain it to me.
it sounds like the area between the piston and the combustion chamber. and he mentioned that for nitrous you want a larger quench area? so should I have my combustion chambers reworked?

YEP !!! SJ