HG set include??
 

the valve stems?

Valve seals? Yes.
If it's the Victor Reinz kit, I'm not sure about other manufacturers kits through.

many944s,

Question,
Some members use an upgraded valve stem seal like silicon instead of the rubber in Victor Reinz kit. What are your thoughts?

Thanks.

John_AZ

I would say it is personal preference...
IMO the traditional Viton seal holds up a little better under hard driving conditions.

The biggest problem with valve seals is they harden over time, thus not sealing well against the valve stem. A common "failure mode" if you will, is the rubber under the metal sleeve that holds the seal to the valve guide breaks down, and the seal rides up the valve stem, rendering the seal useless.

-Nick

Thanks Nick,

I'm not familiar with "Viton". I found a site that helped me understand better.
http://www.westpaminis.com/vitonseals.html

More info:
Viton valve stem seals are made from hi-temperature Flouroviton with Teflon to prolong valve stem life and have a spring on the wiper to maintain a positive seal.

John_AZ