Engine Sealant Clarification Needed
 

Have read the nicely done posts on sealants and have one question. The consensus was to use Curil K-2 for the cylinder base to engine case gaskets. I assume this comment was meant for the copper gaskets on some motors.

What sealant is being used where the cylinder base to case gasket is a Viton O-ring?

You don't need a sealant there, but a non-hardening sealent such as Curil-T or Hylomar wouldn't hurt.

Thanks Chris.

Yes your assumption that the K2 recommendation is for the copper base gaskets.

Curil or Hylomar sticky stuff works good but I don't like it that well on o-rings. I like the o-ring to be free to shift or relieve itself if needed- like during assembly when being compressed.

Dow Corning 112 paste is rated to 450F and seems like it'd work excellent in the case of the cylinder o-rings?

Thanks Kevin. Based upon responses received, I'll either install this O-ring dry or will use the Dow 111 teflon paste.

what are people using in the three oil cooler seals?

I have a dry fresh rebuild except a slow leak at the cooler so Im dropping the engine to do a valve adjustment, tunnel fuel line replacement and that oil leak all at the same time this summer since our driving season is about over.

Dow Corning valve lubricant paste. 111, 112, 55, whatever you can get (220...... 221......... whatever it takes........ 220/221 Volts Whatever it takes? - YouTube ). Basically its silicone paste like Sil-Glyde you can get at the local auto parts store.

I have an extra tube of 112 if anybody wants it. You use so little of this stuff that the tube lasts forever. Dunno about the shelf life but it always seems to maintain the same opaque white sticky paste consistency.

I have the 112. Found it odd that this is the only leak i have so wanted to confirm. Thanks Kevin!