BAYSIC_GSR

what size gasket should i use for a .25mm bore i cant seem to find one at 81.25mm help please? (have ctr .25 oversized pistons)

anothersickhatch

oem should be fine. the oem gasket uses a tad bit of clearance on the inside diameter of the cylinder walls and .25 isnt all that much.

i used an oem gasket on my oversized pistons.

1LowSol

Or you can try this.

http://www.c-speedracing.com/howto/c...c/compcalc.php

anothersickhatch

what does a compression calculator have anything to do with his question?

jdm602

you need 81.50mm.

BAYSIC_GSR

yeah i was told oem was fine by my shop teacher today. its my first build im learning its a lot more harder than i originaly thought

jdm602

well first off its .02" or .025" over which will make it 81.5mm bore. not 81.25 bore. therefor you need a 81.5mm gasket. if you had a smaller gasket think about what that will do to the flow...not good.

93egSLEEPER

.02 is pretty standard for an overbore. an OEM should be fine.

BAYSIC_GSR

thanks guys apreciate the advice.

anothersickhatch

since ctr pistons only come from japan and are only used in civic type r motors, would'nt you think that they would use the metric system? hence, a .25mm oversized piston would still be .25mm over, not converted to hundredths of an inch like the standard system.

Targa250R

As already stated, the OEM head gasket is fine; there is enough clearance for a 0.25mm overbore.

jdm602

well shieettttt i was assuming cause most of the time .020 over is usually in inches not mm. so ya i guess stock bore hg will work just fine.

BAYSIC_GSR

i put mm in my first post why would you think its standard

jdm602

i thought you were saying something else. duh.