Had one of my heads apart--one intake valve out--and while rummaging thru all my pack-rat crap I came across one chevy intake PC seal. Soooo.......

I look at it and slide it on the valve stem--perfect fit!- -just like the chevys I used to put these on--Sooooo......

I put it on the guide top--again, a perfect fit! Soooooo....

I put the valve back into the guide and trial fit this seal again......Perfect fit! Sooooo............

I leave it there and put the spring and retainer together and then compress the valve wayyyy past where stock would be--no fouling! Soooooo........

In my turbo motor I am building--these would be prudent,,,,No?????

Any first hand experience running these before????

I think valves in an aircooled motor run significantly hotter.. could be a problem?

I know that t1s came with them stock.

what it means that VW chose to leave them off the t4 I don't know.

Never seen a T4 with valve stem seals other than a little POS that looks like an injector o-ring. Never seen any on a T1, and I've been working on them since 1960. Howya gonna get oil to the stems with seals on 'em? The Cap'n

We don't run them unless we DLC coat the valves.

With DLC basically the valves could run with no oil and almost be okay!


The stuff kills friction in its tracks!

QUOTE (Cap'n Krusty @ Jan 17 2005, 07:40 PM)

Never seen a T4 with valve stem seals other than a little POS that looks like an injector o-ring. Never seen any on a T1, and I've been working on them since 1960. Howya gonna get oil to the stems with seals on 'em? The Cap'n

well the guides are bronze?? ( looks more like brass, but straight brass would be wayyy too soft for any application of this sort)--just like what all the V-8 guys use--self lubricating-they never really have issues unless real out of the world valve lifts and side loads are used... throw swivel feet into the picture and even more side load is taken away...

If not--they are the exact same diameter as the bronze ones in a chevy V8--could easily use those. ( Wonder if Porsche / VW ripped these off the shelf for ease? )

I know there are heat issues--but only really with the exhaust ones--those can be reamed for a little more tolerance stem to guide wise--this would prevent siezing--

I am just theorizing aloud----

I am sure someone here has actually done testing on this--it makes just too much sense..it would be too beneficial to keep the internal pressure rise at a minimum. Especially seeing as how most engines last only 80k-100k ( Hopped up that is) So if they would last up to this point..hmmmmmmm

I also am up and up at the V8 guys using a vacuum pump to put about 14 inches of vacuum in the block--they have reported a HP rise of up to 35 more!!!!

QUOTE (Jake Raby @ Jan 17 2005, 08:09 PM)

We don't run them unless we DLC coat the valves. With DLC basically the valves could run with no oil and almost be okay! The stuff kills friction in its tracks!

Jake, is that the stuff that is sprayed on pistons and the like and then baked in an oven to cure it???

Or is it a more involved process??

Hell no!

All that home applied shit don't work...

This is a VERY involved casiciam process..
http://www.aircooledtechnology.com/coatings_2.htm

The parts you see in those pics cost 1128.00 to have coated!

QUOTE (Jake Raby @ Jan 17 2005, 08:36 PM)

Hell no! All that home applied shit don't work... This is a VERY involved casiciam process.. http://www.aircooledtechnology.com/coatings_2.htm The parts you see in those pics cost 1128.00 to have coated!

HOLY SHIT!!!

From what I have seen so far its worth twice that in what it allows us to do!