I haven't tried it (yet), but my cam grinder (Crower) and the local
parts house
highly recommend Kendall GT-1.
Their 20W-50 has a zinc content of 0.11-something percent, which is
pretty high. The
stuff I saw on the shelf is SAE SL, but newer lots may be SM.
I use their 30W in my lawnmower--it's green (literally), which is kinda
neat. Dunno about
the 20W-50.
FWIW, the parts guys say it's better than Valvoline VR-1, and a bit less
expensive.
Gary,
You didn't think you could end this thread THAT easily, did you? ;)
bs
Editorgary@aol.com wrote:
>Thanks to everyone who responded, including those who sent me links to
>treatises that would have made good engineering PhD theses. Here's what I
>believe is
>the general consensus.
>
>ZDDP (Zinc d...d...phosphate) is an important additive for our engines since
>it works with molybdenum additives to protect the wear surfaces on tappets and
>cams in classic engines. However, it isn't needed in modern engines with fuel
>injection, roller rockers, etc. and reduces the life of catalytic converters,
>so the API is no longer allowing it to be added to oil for general passenger
>car use. That means that any brand which is now API approved in the long run
>will be harmful to a tappet engine.
>
>However, Castrol GTX 20-50 and Valvoline VR1 20-50, both of which are readily
>available still have the additive, though one respondent noted that he'd read
>that the amount in Castrol has been reduced. In addition, good quality oils
>for diesel engines, such as Chevron Delo, continue to include the additive
>since they don't have catalytic converters and some wear issues similar to
>tappet
>engines.
>Also, boutique oils such as Redline, Royal Purple, Torco, Amsoil, and
>Penrite, which are used primarily by vintage racers, still have the additive
>in their
>non-synthetic oil and have the weight range we should be running in our
>older engines -- though they're typically around $5 a quart. However, since
>you
>only change your oil once a year, maybe the extra $30 a year in return for
>good
>engine life isn't an unreasonable price.
>Thanks for your input.
>Cheers
>gary
>
>
>
***************************************************************
Bob Spidell San Jose, CA bspidell@comcast.net
'67 Austin-Healey 3000 '56 Austin-Healey 100M
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