Why does a 250R big bore leak around the head gasket into the piston? The cylinder and head have been milled flat. Tried different gaskets and it still takes in water.

Got a race tomorrow and need HELP ASAP!!! Any and all suggestions appreciated.

 

If its just leaking around the water ports try some High Temp RTV Sealant. Remeber just around the water jackets.

Mac

 

It leaks because there is less area for the gasket to seal on. Do not use any silicone it can collect in your radiator.
I use a spray on copper made by Permatex, it comes in a gold can.
This works well with a metal gasket, just give each side a couple of coats and let them dry.
ERIC

 

Check that the sleeve itself isn't leaking. I've seen a re-sleeve leak between the cylinder block and sleeve at the top of the exh port. Try pressure testing the cylinder.

O-rings work best with a resleeve. Cut the o-ring grooves into the cylinder instead of the head. They fit much easier. Did the machine shop counterbore the stud holes to accept the stock head studs. If they did, you can't run o-rings unless you are able to put inserts into the counterbores to provide a surface for the grooves.