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)

[Jake Raby]

I can't stand not posting on this topic.

If Stainless valves are horrible I have over 900 engines that are time bombs! Thats because I have not used a Sodium filed valve since around 1994 for ANY APPLICATION!

The Sodium valves were leading edge in the 1970s, today the technology behind the tainless valves is much higher than it was in the 70s. I have had 3 valve failures with stainless valves in the past 7 years, two of which were in full blown race engines, spinning 8,000 RPM and the owner did not complete valve adjustments at my specified intervals. The last one was recent when a customer installed a set of ratio rockers against my recommendations without even checking valve train geometry. It was an intake valve, not an exhaust!

All my personal cars run stainless valves from SI industries along with all my engines. This includes engines in my "Super Hero" line up, even the Mighty Spyder! Not all stainless valves are created equal, some are pure junk, while the SI valve is incredibly strong and light and can take the abuse of a full bown race engine.

For someone to recommend a used sodium filled valve over a brand new Stainless version is pure stupidity and shows one thing: lack of experience! I had to read that one 3 times and I still didn't believe it- pure bullshit!

Thats because experience teaches us at teardown what fails and if you had seen as many engines blown to bits BECAUSE OF SODIUM VALVES as we have you certainly would not make this statement. Have one failure due to Sodiums and you won't say it, see a few dozen more and you'll be about as experiebced with it as we are.

When a Sodium valve goes without adjustement, or when it gets ready to let go the valve explodes and blows the piston and even the cylinder to bits! I have had this happen on my 914 engines when it was stock and nothing could be reused- not even the case, or the crank or even the rods! I have seen this many times and even more severe. I posted the pics of the failure in 2002 and most people swore the engine was turning 8K, nope a chick was driving it!

The other issue with Sodium valves is that they are only made in 9mm stemmed versions that weigh about 17 grams more than our stainless steel version and 17 grams of valve mass is worth it's weight in gold for valve control.

So there ya have it, the view that experience has taught me about Sodium valves. We do not use Stainless valves because they are cheaper, we use them because they are BETTER- period. Racer Chris turns his 8,500 RPM for a full season with no sweat at all in a 186HP 1832cc engine, that should speak volumes.

Okay, back behind the curtain, I just had to stop the Bullshit that was starting to get deep in this thread!

BTW- if you don't agree with me, then (IMG:http://www.914world.com/bbs2/html/emoticons/pissoff.gif)

(IMG:http://www.914world.com/bbs2/html/emoticons/ohmy.gif)

Hey, maybe someone should go chuck up a Sodium valve in a valve grinder and see what happens. Alpha, wanna go try it?? You'll be geting out of the hospital about the time I come back to the forums, I would hate for you to miss my posts-