Ross (or any brand) Pistons and Cometic Gaskets

[Quadzilla]

When I called Ross to order my piston, I spoke to "Honda Jim" who is in charge of their motorcycle pistons. He told me at that time (3 months ago) that the piston compression was rated for the XR's and that I would have to use XR gaskets to get the advertised compression ratio. Maybe this has changed in the past 3 months, not sure. I went to Ross's website and looked at their online catalog. There is no listing for an EX piston, just XR which would lead me to believe that they are the same piston which substantiates my conversation with Jim.

The only "wildcard" could be that the Cometic gaskets could effect this. Dusty from C & D told me that they come in regular and thin sizes. If the "thin" is thinner than an stock XR gasket, this could raise the compression to higher than advertised on the piston. Does anybody here know if the thin Cometics are thinner than a stock XR gasket? Thanks!

[Hondaluva]

Cometic makes a ton of different thicknesses of gaskets. They go as thin as a .027" stainless head gasket. Here is a number for Cometic...(440)354-0777

You will have to ask somebody else what the stock gasket thickness is on the XR. I doubt the sealership would know.

[garysol1]

you know ice racing season will be here soon...:)

[Quadzilla]

Colby from C&D more or less answered this on another thread...

Quote from Colby
"The thinner head gaskets that I sell are thinner than the xr gaskets by 8 thousands and 18 thousands thinner than the 400ex gasket. I also provide a thinner base gasket to change the squish area for better burn and cooling this also helps to raise the compression the base is 8 thousands thinner than stock. So yes with our thinner gasket kit you will have more than the advertised comp ratio"