Using o ring as head gasket?

[tygertung]

What do you think about this idea? Wouldn't be hard to do, just get some high speed steel, grind it into an o-ring groove shape and machine a groove in the head. Wouldn't have to worry about sealing the head with head gaskets or anything. Could use a high temperature rubber o ring. I'm pretty sure this method is used on KTM dirt bikes.

Any thoughts? :scoot2:

[skuttadawg]

Gaskets are cheap to buy and rubber would melt

[tygertung]

I don't know if it would. The head only would be getting to perhaps 140 degrees c and oil seals for 4 stroke engines don't tend to melt and the oil can easily get that hot.

[lshigham]

Most, if not all, after market Minarelli and Piaggio cylinder kits available in the UK come with O rings, they do melt, but only if the engine severely overheats. Piaggio 50cc engines come with an O ring head gasket standard

For example: www.pedparts.co.uk/product/1207/motoforce-racing-70cc-cylinder-kit-mid-race-piaggio-air-cooled

[bare]

Viton O rings Do Not "melt'. Someone is selling/inserting Chinee Crap rings :-)
Gee.. that's never happened before?
Oring seals require the cyl head be machined to fit a ring.

[jmkjr72]

liquid cooled kits run oring head gaskets

also there are many after market kits that run oring gaskets