Let's throw in some actual user experience, then.
When I took the head off my B engine, it had serious valve recession and
extreme cam and lifter wear (several cam lobes were worn down almost 0.2
inch). This was a non-smog high compression Gold Seal engine from the late
80s, with around 85K miles, almost all on Castrol GTX 20w50.
So, I am convinced that current formulations of the factory recommended
lubricant are inadequate for tappet protection. The service manual no longer
applies.
--
Max Heim
'66 MGB GHN3L76149
If you're near Mountain View, CA,
it's the primer red one with chrome wires
on 9/24/09 6:04 AM, Steven Trovato at strovato@optonline.net wrote:
> Yes, can't disagree with that. Once again, the only thing I was
> trying to do was explain how a manufacturer could claim two API
> specifications without "making a mockery of the system". As for my
> actual opinion on the ZDDP issue, which I have not actually stated
> yet, I look at it like this. Maybe there is a problem with low ZDDP
> oils and maybe not. I have read dozens of opinions and I still don't
> know. My personal decision is to use Castrol Syntec 20W-50,
> "formulated for classic cars". Castrol states "The level of Zinc in
> the new Syntec 20W-50 is a minimum of 1200 ppm, which will provide
> excellent anti-wear protection for the cam and lifters in a
> flat-tappet cam engine." The only downside to this seems to be that
> it costs a lot more than the Castrol GTX I was using. And it was
> hard to find. Maybe there's a real issue here, maybe not. Risking
> major engine damage (whether the risk is real or imagined) versus a
> few extra dollars, it seemed foolish to just ignore the issue. As a
> wise fellow named Paul Hunt once said, we are on our own, and have to
> make our own decisions.
>
> -Steve Trovato
> strovato@optonline.net
>
>
> At 04:12 AM 9/24/2009, Paul Hunt wrote:
>>
>> The whole point is that there are many claims out there, some are
>> undoubtedly correct, some are confused, some are incorrect and some
>> are downright lies. How are we to know which are which if not for
>> actual experience? We are on our own, and have to make our own decisions.
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