[T3] Hothe's numbers

[Jim Adney]

On 2 Jul 2012 at 23:00, Keith Park wrote:

> I find sometimes things loosen up a bit, I occationally find a valve at
> ,.007 or .008, maybe its different temps but the cam in this engine has over
> 150K on it as it was in the previous builds, I know its worn, I can see it
> up in there when I drop the sump plate and it did go thru some time with
> less ZDDP before we knew that it had been taken out.

Your experience is not typical. The usual wear area, where things get 
hot, is at the valve/seat interface. If you think about it, wear here 
will make things tighten up. This is what happens normally and this 
is why skipping valve adjustments is a bad idea. (Tight valves lead 
to problems, while loose valves don't.)  

While there will always be some wear at the cam/lifter interface, 
which makes things loosen up, this should always be minor compared to 
the valve/seat wear.

I had loosening valves with the second engine I ever built. Turned 
out that I had bought "Made in W. Germany", plain brown box lifters, 
which were known to be too soft. That was in about 1975, so I can't 
blame the oil. Friends here explained the problem, Berg agreed, and 
the Rockwell hardness tester at work confirmed it all. New, correct 
hardness, lifters fixed the problem. YMMV.

Now I tend to reuse OG cams, with lifters I buy from Berg or 3-part 
Brazilian Eaton lifters that Berg confirms are correct. I haven't 
bought any lifters in years, so I'm not sure what's good these days.

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