Don Terrill’s Speed-Talk

echosixmike wrote: ↑Sun Oct 15, 2017 1:23 am For the OP, I've have dozens shortened by Jarvis Performance, wound up being about $10/valve. Mostly for BBM, so were 4.950, plus a lash cap. Seem to work OK so far.

https://www.facebook.com/jarvisperformance/

With the 7mm and larger stems, you may find hollow stem valves, which obviously can't be shortened. Kinda the risk of the game. I now have a 7 valve set of too long valves due to this discovery, lol. I think the exhausts are going to be solid, but I suppose they might be sodium filled or some awfulness. S/F....Ken M

Thanks Mike... good FB link.

You could always check out candidate valves via Archimedes' Principle: weigh the valve then check its displacement with a graduated cylinder and calculate its density.
Water of course has a Specific Gravity of 1.0 and most steels are ~ 7.7, so if a steel valve weighs say 120 g. it will displace 15.6 grams/ccs of water if it is solid construction. If it displaces more it's sodium-filled and/or hollow. You won't likely encounter hollow titanium valves, but JIC, its S.G. is ~ 4.5.

englertracing wrote: ↑Wed Oct 11, 2017 12:32 am

perfconn wrote: ↑Tue Oct 10, 2017 2:33 pm Negative.The stems do not have to be coated.Out of several hundred sets of cup valves I have used none had the stems coated and only one set had the heads coated.The stems ride on a film of oil just like bearings do.Only stems I have seen coated were Manley.Never Del West or Exeldyne.

Every Del West or Exeldyne is coated with Chromium nitrite, on the stem and head, or chromium nitrite on the stem and titanium aluminum nitride on the head.

The Chromium nitrite looks just like shiny silver.

Molly coated stems and raw valve heads is old school.

Many of the above valves mentioned still use molly as the prefered stem coating.

Well I got my Ti valves and lash caps for my future project engine. Look pretty nice.

Bad new is my old friend from my racing days at Hales Corners Speedway ho has also been advising me on this stuff has passed away... Jimmy Watson worked for 9 years in the engine shop at Roush-Fenway and moved to Furniture Row racing this year after being with another team last year. Jimmy was a helluva driver and fabricator and he did the crank work at Roush but was an expert at most of the engine stuff. He pretty much gave me the green light on buying the used Cup stuff that I've purchased in the past year.

So now you guys are back in the #1 chair as far as keeping me headed in the right direction on my engine builds... you've got big shoes to fill!

That's Jim in the 0 car at the Hales Open show in WI and also him in the "W1" car also at Hales...

RIP Jimmy....