<VV> How MUCH Phosphorus and Zinc?

[Eric S. Eberhard]

Well -- maybe not.  But all things were equal except one cam (which 
was NOS) ... they were Clark's which have been before and after this 
fine.  And the mechanic is the same guy.  And they were inter-mixed 
(one cam went round, it was replaced, and I broke it in with Mobil 1 
... then another was rebuilt and I used Mobil 1 immediately, then 
another was rebuilt, and I listened to the mechanic's whining about 
breaking in with synthetic, and ... flat cam ... and then replaced it 
and broke in with Mobil 1 and it was fine.

I agree the zinc is to spec'd -- but the cam mfg claim this is the 
problem (could not be their cams!) -- so I look for high zinc and 
phosphorous ... but it could also be luck, this is a sample of 5 
which convinces me on some level, but does not rise to the level of 
absolute proof.

I will say my 80 Toyota truck (bought new, always used Mobil 1) has 
240k on it, several pickups used for towing horse and car trailers, 
all senior citizens well over 100k (and the turbo diesel gets hot!) 
... I have had nothing fail on them ever in the engine.  A/C 
compressor ... something else!  I also use synthetic in the 
transmission (Mobil 1 too) and change it every 50k ... still going!

Whatever works for you.  E

E


At 03:44 PM 3/18/2010, BobHelt at aol.com wrote:
>In a message dated 3/18/2010 3:28:12 P.M. US Mountain Standard Time, 
>flash at vicsmba.com writes:
>And from my reading, lack of
>zinc is what causes the rounded cam problems.  I had two engines go
>flat on the cam lobes in less then 8000 miles.  Both were broken in
>the "traditional way" using 30 wgt dino oil of the mechanic's
>choice.  When I tore them apart and put a new cam in, and on a third
>engine I rebuilt thankfully once, I broke them in with the Mobil
>1.  It says on their site it is safe for break in.
>
>Well it could have been the oil that was the problem, but also a 
>very possible cause were soft lifters or even bad cam lobes, not 
>properly hardened. You will probably never know for sure but my 
>guess is that it wasn't the oil that caused your problems. And as I 
>said, the presence of zinc and the amount is not required or spec'd 
>in today's oils.
>Regards,
>Bob Helt


Eric S. Eberhard
(928) 567-3727          Voice
(928) 567-6122          Fax
(928) 301-7537                           Cell

For Metropolis support and VICS MBA Support!!!!    http://www.vicsmba.com

Fun personal pictures:  Includes horses, dogs, Corvairs, and 
more.  http://www.vicsmba.com/ourpics/index.html

However, most new pictures are on Facebook.