[T3] HD valve springs

[Jim Adney]

On 15 Apr 2012 at 19:29, Keith Park wrote:

> OK, Im about to remove the inner springs from my Berg heads as the valve
> seats have been sinking in since I got it and Im told that I don't need them
> since Im never winding this out to the redline.

If that leaves you with standard stock springs, then that's a 
reasonable thing to do, but it may leave you with weaker than stock 
springs, in which case you should remove both springs and replace 
them with stock springs.

Stock springs have always worked just fine for me up to the rpm limit 
of the FI, which is about 5k. I agree with Brian that dual springs 
with a 110 cam seems pointless.

A friend who knows about these things has told me that NO valve train 
likes to run above about 3500 for very long at a time. Short bursts 
are fine, but sustained runs lead to reduced lifetime. I'm just 
guessing, but I suspect that valve stem lubrication fails above some 
speed. For short times, the oil that was in there will work, but 
isn't getting replaced, and it's getting driven out.

I know the next question is gonna be, "How long can those short 
bursts be?" I don't know, but I suspect it would be something like a 
minute or so at a time.

-- 
*******************************
Jim Adney, jadney at vwtype3.org
Madison, Wisconsin, USA
*******************************