platinum00

What is the recommended piston to wall clearence and ring gap for CP. 9.1

This is for a sohc stock bore with moderate boost levels 15 - 20 psi.


thanks

platinum.

eddyboy

This is what my friend and I went with
We both have d16z6 with CPs

For the wall clearance we went with what was recommended on the CP spec sheet.

As for Ring Gap check out this post
https://honda-tech.com/zerothread?id=904607

yellowturbo

if you have any other question pm Earl on the board... I followed his instruction for my CP and my engine run like a charm and the leak down looked good at the begining of the season... I want to do another leak down tonight before storing the car.

earl

With CP's, if you have a 75mm piston, bore your block to exactly 75mm (NOT 75.01 or 74.99mm). The clearance is built into the pistons. If you follow this rule, you will never go wrong.

platinum00

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by earl &raquo;</TD></TR><TR><TD CLASS="quote">With CP's, if you have a 75mm piston, bore your block to exactly 75mm (NOT 75.01 or 74.99mm). The clearance is built into the pistons. If you follow this rule, you will never go wrong.</TD></TR></TABLE>

well you sleeved and bored my block, so im assuming this is correct

thanks for the info guys.

platinum.

RyanEJ8

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by earl &raquo;</TD></TR><TR><TD CLASS="quote">With CP's, if you have a 75mm piston, bore your block to exactly 75mm (NOT 75.01 or 74.99mm). The clearance is built into the pistons. If you follow this rule, you will never go wrong.</TD></TR></TABLE>

Are the CP pistons designed for FI only? I ask because normally less clearance would be used on an N/A motor.

stealthmode62

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by earl &raquo;</TD></TR><TR><TD CLASS="quote">With CP's, if you have a 75mm piston, bore your block to exactly 75mm (NOT 75.01 or 74.99mm). The clearance is built into the pistons. If you follow this rule, you will never go wrong.</TD></TR></TABLE>

Does this apply to all of their pistons, or is 75mm the only one?

platinum00

ttt

93LSivic

Typically the CP's will use a .0035" piston to wall clearance for their low compression slugs. Atleast thats what I noticed on the B series stuff that I've built. I have gone as far as .005 on high boost applications, but they tend to be a little noisy.
Only thing that sucks about the CP's is that if your not sleeving a block then they arent the best piston to go with if you want to stay with stock bore. Since they are pretty much "undersized" then you absolutely need to go .5mm over and when doing this you obviously remove cylinder liner material causing them to weaken.

earl

JE's and Wisecos are built with the clearance in the piston now also.
As to CP, if you buy a higher compression ratio piston, the clearance for that all motor piston is also built in. But in that case, they change the clearance to .003".
If your machinist doesn't try to out think CP, you will have a quiet, happy motor.

Sonny

earl:

I don't quite understand how clearance can be built into a piston. Do the specs require that the machine work be done at a certain temperature?

If you tell me to bore my block to 75mm and it's 20 deg in my buddy's shop, the clearances will be different when I take it to my 100 deg house (it's winter time...I like it hot ) and assemble things.

Sonny

i-speed

If your gonna sleeve it, try step decking it .I run 30+psi on my step decked blocks and a little shot of laughing gas. Also try some high temp aluminum paint w/ ceramic like plasticote brand on the head gasket.

earl

Which expands more at 20 degrees, the aluminum or the cast iron when taking it from 20 to 100 degrees?