XR Gasket?

[jcs327]

This may sound stupid, but I have heard that if you run an XR head gasket in the 400ex that it will increase the compression to 11:1. (and I thought it was an XR engine anyways) Is that true?Thanks

[cals400ex]

this gasket will not raise the compression to 11:1. it will raise the compression but the piston being used mainly matters. most pistons cut are for the xr400 and the 400ex. well the companies use the xr400 into account. so, if you run a true 10.8:1 piston in a 400ex with the xr gaskets, it will be a true 10.8:1. if you run the stock gaskets with this same piston, it will be less than 10.8:1.

now, you can go buy a piston specifically designed for the 400ex and not the xr. this can be purchased thru many engine builders. this piston will be the correct compression ratio with the stock 400ex gaskets.

[jcs327]

so, in reality, I would not see any difference in changing gaskets?

[cals400ex]

i doubt the difference would be much noticable. i actually prefer the cosmetic flexsteel gasket kit. these are suppose to be a little thinner than the xr gaskets and the quality seems good. i would just get these from C&D. they will be able to hook you up with what you need.