This topic has been beat to death on other lists (the Healey list for one).
The consensus is Valvoline VR-1 racing
still has adequate ZDDP. Besides that, there are some specialty brands that
still have ZDDP, or you can go with a
synthetic like Redline, or use an additive. Some swear by diesel oils like
Shell(?) Rotella. Castrol may still have
some ZDDP in the 20W-50 oil, but the oil companies have been kinda coy about
revealing what's really in their stuff.
Dunno about aircraft oils. Light plane engines are usually hydraulic
lifter/pushrod engines, so the oil would need
some extreme pressure additive (and no cat to worry about). OTOH, A/C oils
are formulated to handle the lead still in
avgas and all the blowby from the sloppy clearances in big air-cooled engines
(Mobil 1 for A/C didn't fare well).
Generally they aren't recommended for automotive use, but might be OK in an
air-cooled bike.
Bob
On 6/26/2011 11:24 AM, David C. wrote:
> OK, I have a 1986 BMW R80RT (motorcycle) with pushrods and solid lifters.
> Any recommendations for oil for a vintage
> engine (I have been using GTX 20W50). Aero oils?
>
>
>
> John Miller wrote:
>>
>> For older engines, especially flat-tappet pushrod engines but really any
>> engine with a lot of bits that slide on each other under high pressure,
>> it can be a very bad thing.
> _______________________________________________
>
--
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Bob Spidell San Jose, CA bspidell at comcast.net
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