OE Exhaust Valves, Sodium Options

[914werke]

I know Jake suggests tossing these, but unfortunantly Im rebuilding a set of heads. Id like to keep them stock, but Im more concerned about longevity.
Is there anything that can be done to improve thier function?

Cryo? (IMG:http://www.914world.com/bbs2/html/emoticons/sad.gif)

[Twystd1]

Somebody explain to me how an Airplane piston engine that never sees the high side of 2700 RPM (with a few exceptions)

has anything to do with what we are talking about?

And airplane engines are either water cooled or air cooled with more air going across the cylinders and the engine than we can even imagine.

Me thinks you are comparing apples to sherman tanks.

Differant application and very differant enviroments...........

Lousy comaparative analysis.... In my non-humble opinion.

AND:

It doen't matter if it's Jake of Len or Brett or Me for that matter that makes a comment on how it should be or what to use. Don't keep shooting the messenger. It's only data... Biased and/or opinionated or not... It's only data.

And what is needed on a race engine isn't always needed on a street engine. Couldn't agree more.

For me... On any engine that can see 6K easily. any valve that has seen 100K in mileage is tossed. Period.

Too much risk of valve seperation. Cause I spin my engines to redline constantly. To expensive to take a chance.

Sodium or not? I use stainless. With new guides.

What you use doens't matter. cause they all work. Including sodium filled.

To which is better for a street engine.

If I used a Raby cam.. I would go stainless. Cause the head temps are down.
If I was to go with a bone stock cam... I would use either one.. and ONLY if they were new valves.

And I have a spare NOS/OEM set of sodium filled 1.7 or 1.8 (can't remember) valves if ya need em.. I will never use them. Not for free... But for cheap...... (with springs, retainers and keepers, intake and exhaust all NOS)

Clayton