I've bought some DT466 parts from a tractor puller in Arkanas who is using these on his DT466. He has used the same set of C-rings and same headgasket for over 3 years. Yes, he as pulled the head on and off multiple times during that time and reused both the rings and the gasket. He said he's never, NEVER, had a head gasket failure of cylinder leak and he's pushing close to 200 psi with triples! I'm going to use them on my DT466. If he can get that kind of reliability with them pushing that much fuel and boost, I'm sure they will be just fine at a "measly" 30 psi.
Sean said Hypermax had no issue with them being used in a daily driver. No offense to Justin, but, don't beleave everything you hear from someone who has never seen them much less used them in a HO diesel.
Yes, the block is machined with a groove around the cylinders on the deck. You can see the machined groove in the block's deck in the 1st picture in the above post. On the DT, you machine the groove in the cylinder sleeve, not the block as they are wet sleeve engines. They call them a "C" ring becuse the are just that, a C. The ring is open not solid. The open portion faces the combustion gases and the more pressure the more it expands the C against the head and block preventing leaks.
Nope, no relation. But, I like the way he does things.
Heath