Two Stroke Cylinder Gaskets

[homerphish]

Are there any materials that are better than copper alloy when used as a gasket in a motorcycle engine cylinder? Preferably something softer or more ductile than copper, but with the same heat resistant properties.

 

[ctmtwilliams]

At the head or at the base?

 

[homerphish]

At the head.

 

[ctmtwilliams]

In 70's we used alum. as well as copper head gaskets. You can soften up a copper gasket by heating it with a torch and quenching it in water. (yeah, its just the opposite of steel) Copper is pretty soft, I don't know of any metalic gasket material softer than copper. Be careful of the thickness of the material you use as you'll change your compression.

 

[EngJW]

There is a book out about the development of the Continental A40 aircraft engine. It had a series of problems related to excessive heat in the head- such as gasket failures and valve problems. Someone tried a sheet of copper in place of the head gasket and the problems went away. The copper allowed heat to transfer out of the head and into the cylinder fins for cooling.

Another issue- some air cooled engines use a head gasket with metal facings. There is more movement between the head and block in an air cooled engine, even more so with an aluminum head and iron block, that a composition gasket can get torn up if it doesn't have the sheet metal over the composition core.

 

[119]

If your having problems with the head gasket leaking you need to look at a couple of other critcals. Check the torque on the head bolts. Because of thermal expansion and contraction head bolts need to be retorqued. Specially on a two stroke. I have found that painting the head gasket with a metalic based spray paint and assembling the motor back together before the paint drys, works pretty good.

 

[adfka]

everything modern is nicasil lined bores and rubber o-ring heads. no gaskets on top.

for base gasket, a rubber covered aluminum gasket.