Unfortunately the vast majority of the "modern" day re-produced crap is
hardly fit for purpose anymore.
During the last twenty odd years that I was building engines I carried out
a modification to the cam followers, this tended to overcome the problems
encountered.
The metal to-day is no longer top quality steel from Sheffield, and I dare
say that in to-day's political correct madhouse it would be illegal to use
cyanide during the hardening process anyway.
Regards.
David.
>
> -----Original Message-----
> From: Rich C [mailto:richchrysler@quickclic.net]
> Sent: Thursday, May 10, 2007 7:28 PM
> To: BJ8Healeys; healeys@autox.team.net
> Subject: Re: Valve job
>
> Hello all,
>
> Another victim of lifter and cam lobe failure was shown to us last evening
> at our monthly Southern Ontario pub nite. A good friend's 100M fitted with
> a
>
> new Dennis Welch cylinder head which came complete with valves, springs,
> guides, etc. The camshaft was fresh at the time of assembly and all cam
> followers were in excellent condition. It has been on the road for 3
> seasons
>
> and 12000 miles. Valvoline 20w50 has been used all along and changes were
> regular. This car is very carefully maintained.
>
> To me it brings a number of points to mind:
>
> 1. Three years ago when the engine was being gently broken in, would there
> not still have been sufficient amount s of ZDDP in the Valvoline oil?
> 2. What are the spring rates of the Welch head assembly?
> 3. Not all lobes or cam followers eroded at the same rate. Some are almost
> still okay while others (#5 especially) are completely broken down.
>
> This is getting scary, but I think all avenues should be carefully
> explored.
>
> Rich Chrysler
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