If I may branch off and address viscosity:
One of the comments that is commonly made about Rollie Free
is that he ran a very low viscosity oil, like 10 wt (or
maybe less?), and one also hears about racers pre-heating
the oil, to avoid running the engine for a time to get
the oil up to temp. I also suspect Rollie wasn't concerned
about getting hundreds of flat out miles from the engine,
just enough miles for that year's meet.
This raises a few questions.
How significant of a power loss difference is there between
running lighter or heavier weight oil?
The Vincent, having roller bearings on the crank and relying
on oil flow, not pressure, is this a more favorable environment
to run a lighter oil, ie can a plain bearing motor cope with
such a light wt oil?
What weight oil would you say (guess?) is the 'norm' for land
speed racers, either overall or separating out bikes from cars?
For whatever reason, I had this perception that all, or most,
land speed racers were running as light a weight oil they could,
and this comment of running 50 wt stood out.
SFD
Thomas E. Bryant wrote:
> List,
>
> I guess I am missing something here! I am "old fashion", I still use
> Pennzoil 20w/50 Racing Oil. My last two engines have run over 250 miles
> flat out without any bearing problems. Should I be using something else?
>
> Tom, Redding CA - #216 D/CC
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