I have a Gsr block with a CTR head, 3layer head gasket.

Acording to the Cspeed Calc im running 9.8:1 which really sucks. Im taking my car off the road for the winter and i want to swap out the pistons.

I can get some CTR pistons really cheap.

With the CTR's ill be around 11:7:1 cr.

Now my question is. Is there a head gasket, that is thicker then stock that will bring my CR with CTR's down to around 11:1 or 11.5:1? Where do i buy it, and what is the thickness of it. Thanks!

This will be on pump fuel 94octane, with just CTR cams. For a mild NA street car.
I can tune with ubderdata, but the car will be driven hard. Thats why im lookin for a lower CR ratio. Somewhere around 11:1 or 11.5:1 with the CTR pistons..

 

I believe toda makes a thicker headgasket

 

Is there a specific reason why you want the CTR's? If you're looking for a C/R in the low 11's, I'd go with JDM ITR pistons and a 2-layer Mugen head gasket.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Padawan &raquo;</TD></TR><TR><TD CLASS="quote">Is there a specific reason why you want the CTR's? If you're looking for a C/R in the low 11's, I'd go with JDM ITR pistons and a 2-layer Mugen head gasket. </TD></TR></TABLE>

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by HamiltonRex &raquo;</TD></TR><TR><TD CLASS="quote">I can get some CTR pistons really cheap.</TD></TR></TABLE>

 

I wont have to visit a machine shop. And since i have to change the head gasket regardless i figured it wouldnt be any extra work. I have an opurtunity to get a set of CTR pistons on ITR rods, all new.

Then i wouldnt have to source out seperate rods and pistons and visit a machine shop.

It seems cosmetic makes head gaskets of various thicknesses that will work very well to bump my compression down to 11:1-11.5:1.

Thankyou.


Modified by HamiltonRex at 4:12 PM 12/5/2004

 

Cometic

im runnin ctr's in my gsr w/ p72 head. with a .043" cometic gasket.

 

0.043" will be perfect for my application. Will bring me to 11.3:1 Easy to tune on pump fuel

 

let me help ya out a bit..... gsr block with b16/b18c head will yield 12.1+ in a gsr block.....there have been many discussions on the actual compresion ratio with ctr pistons due to the piston having different wrist pin locations then rest of honda pistons.... word is they will make a 13.1, but only way to tell is messure the cc in ur head and calcuate it urself....

so go with itr's or p30 slugs if want someting more in the 11's

i currently have this setup in my b18c block and looking ot go boost now so if ur in the market for shot peened gsr rods and ctr pistons (900 miles on them) let me know 250.00 shipping

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by W C L &raquo;</TD></TR><TR><TD CLASS="quote">let me help ya out a bit..... gsr block with b16/b18c head will yield 12.1+ in a gsr block.....</TD></TR></TABLE>

Im looking for new. And a b16 block PR3 will have a lower CR then a b18c p72 block due to the combustion chamber size.

Thanks, ill do some more research. Im just going by the cspeed racing calc.

 

gsr head will only raise compression .2 points due to combustion chamber size....

 

If you have daily access to 93 oct, ctr slugs are fine as long as your setup is properly tuned at about 13.2:1 a/f accross the board at WOT.

 

13.2:1 is far too high.

I have ubderdata and acess to a wideband that i could street tune.
Theres so much controversy between what compression ctr's yield. Im going to research more and find out what headgasket i will need for around 11.5:1

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by HamiltonRex &raquo;</TD></TR><TR><TD CLASS="quote">13.2:1 is far too high.

I have ubderdata and acess to a wideband that i could street tune.
Theres so much controversy between what compression ctr's yield. Im going to research more and find out what headgasket i will need for around 11.5:1 </TD></TR></TABLE>

AF ratio, not compression ratio.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jdm_ef9 &raquo;</TD></TR><TR><TD CLASS="quote">Cometic

im runnin ctr's in my gsr w/ p72 head. with a .043" cometic gasket.</TD></TR></TABLE>
yeah that is what i was gonna say

Very good head gaskets

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by arw321 &raquo;</TD></TR><TR><TD CLASS="quote">

AF ratio, not compression ratio.
</TD></TR></TABLE>

oopsie..

Seems like 12:1 is where i will end up with a 0.043" gasket. Ill just tune well

 

can i run a stock b18c head gasket with ctr pistons w/o it blowing?

 

your compression with a gsr block and ctr head is actually in the 12.6:1 area if you want to be @ exactly 11.1:1 you need PR3 pistons. which i have a set lmk

 

If anyone has any doubt what their compression ratio will be with CTR pistons, just read the sticky post at the very top of this form since it deals with this specifically. The info in that thread IS accurate and uses numbers directly supplied by Omniman.