I think this is the kind of failure ZDDP is supposed to help prevent. I
doubt Mobil 1 has a lot of ZDDP in it; it was basically 'outlawed' in
all but 20W-50--since very few modern cars use that weight and even
fewer have flat tappets--and I don't think I've even seen M1 in that
weight.  It doesn't sound to me like you did anything wrong with your
driving habits; just a bit of bad luck maybe. My last rebuild I got a
DW 'gun-drilled' cam, which I hope helps prevent lobe wear.
Decades ago, Mobile made a 'Mobile 1' for aircraft and it was an
unmitigated disaster; it didn't scavenge the lead in 100LL and the lead
gunked-up rings (esp. in 'big block' Continental engines). I heard a
few unscrupulous aircraft owners got new engine rebuilds if they used
it, even if they didn't have a problem (a rebuild on a big Continental
can run $50K or more). In the piston aircraft community, it was gospel
that you used multi-vis oil only in the winter, and straight
100W--equivalent to 50W motor oil--in the summer and because it
supposedly left a thicker film of oil on the moving parts (most piston
aircraft have hydraulic lifters).
Bob
On 4/27/2020 1:41 PM, Wayne Schultz wrote:
> Hello everyone, I recently completed a rebuild of the engine in my
> Healey 3000. At 48K miles i noticed metal during an oil change. I
> dropped my oil pan and found even more metal and a silver ring in the
> block that lined up with a cam lobe. I had been using Mobil 1 for
> years and always had good oil pressure and a very quiet motor. I
> pulled the motor and upon teardown I found one bad cam lobe and
> several lifters that had mild pitting. I thought about how I used my
> car and came to conclusion I, rather than the oil might be theÂ
> reason for the cam failure. I drove my car every couple of weeks in
> nice weather. This is just enough time for the oil to leave the cam
> and lifters to drain into the pan. This meant the next time I started
> the engine the cam and lifters might have been metal on metal. My new
> lifters are short bucket lifters with a drain hole to lubricate the
> cam lobes. Now using VR-1 20/50
>
>
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