Rebuilding tips -Seals and Gaskets

[Davehuge]

I've rebuilt a few engines over the years, not hit many priblems but I'm always looking at ways of improving what I do.

So what about installing O rings and gaskets, leave them dry or lubrcate them, it would be great to hear the opinions of experienced engine builders.

O rings - I have a tube of silicone grease that I would consider using on O rings, my thoughts are it would help keep them in place during installation, prevent them sticking/being damaged during disassembly and prevent them hardening?

Gaskets - Is it a good idea to grease or oil gaskets before installation? My thinking is it would hold them in place during assembly and also avoid them sticking/tearing during disassembly.

Please let me know your opinion!

Thanks and all the best, Dave.

 

[Jacob 'Berg]

I've rebuilt a few engines over the years, not hit many priblems but I'm always looking at ways of improving what I do.

So what about installing O rings and gaskets, leave them dry or lubrcate them, it would be great to hear the opinions of experienced engine builders.

O rings - I have a tube of silicone grease that I would consider using on O rings, my thoughts are it would help keep them in place during installation, prevent them sticking/being damaged during disassembly and prevent them hardening?

Gaskets - Is it a good idea to grease or oil gaskets before installation? My thinking is it would hold them in place during assembly and also avoid them sticking/tearing during disassembly.

Please let me know your opinion!

Thanks and all the best, Dave.

My practice has been to use a few dabs of grease to hold the O-rings or gaskets in place during installation.

With the cylinder O-rings, I typically stretch them a little bit over the cylinder to keep them from popping out of the channels when placing the head.

 

[Zman]

O-rings need to be lubricated to seal properly. Silicone grease works well on the head O-rings. I have found the head O-rings need to be stretched a few times to fit properly in the ring-land. On the GG bikes I have run all other gaskets dry with no leak issues. This makes it easier for later disassembly. On the other hand, if you plan to play submarine, I would RTV silicone the ignition cover gasket and rubber plugs for the wire passages.

 

[Jakobi]

I've always put a smear of waterproof grease on my gaskets/on the gasket surfaces. Simply helps hold the gasket in position during assembly, and as a bonus I've found that they tend to come back off again easily and in many cases can be resused (powervalve, ignition, etc).

Also found head O-rings a bit of silicone and a few stretches to get the fit nice.

 

[(F5)]

One day someone will specify an o-ring that is the right size for the groove. Head ones need a stretch. Light smear of grease or rtv will help hold in place but don't put too much, as the space around the o-ring is important so don't fill it up with incompressable products.
When you place head on gently lower it checking it hasn't put a leg out of bed.

I always light smear of grease on gaskets as Jake suggests.

 

[Davehuge]

Yes, I see what you mean, the cylinder head O rings need a slight, gentle stretch, but no big problem.

 

[gasgasman]

I use spray trim adhesive on the gaskets.
After stretching the head o-rings, I use the spray adhesive in a couple spots to hold them in place.