FWIW- We've had some problems not getting our rings to seat in on our 1300
Spitfire using synthetics. Redline recommends running with mineral oils
until smoking stops. However, That's a judgement call which we made too
early last year. DEFINITELY run a MINIMUM of 500-1000 miles before changing
to synthetics.
Mark Haynes
'62 HAN6
> -----Original Message-----
> From: Michael Dietsche [SMTP:mdietsche@yahoo.com]
> Sent: Monday, March 15, 1999 9:50 AM
> To: Bkitterer@aol.com
> Cc: MG List
> Subject: Re: Oil and Oil coolers
>
> This pretty much agrees with conventional wisdom out here in Oklahoma
> (where we don't bother to marry our cars -- we just shack up with
> them). Sump oil temp above 200 is desirable, with preferred range
> around 220-230 for small engines. The reasoning is that colder temps
> don't fully dissipate the entrained acids and other blowby compounds
> that wind up in the oil, and these compounds are damaging to the
> engine. It's true that conventional oil deteriorates at these temps,
> but that's why you change oil regularly. The newer synthetics and
> blends are much more temp-tolerant and can run hotter with less
> deterioration.
>
> Oil coolers make sense if you are running hotter than this with
> conventional oil, esp. in the summer. This problem might show up as
> low pressure after a long summer drive, with the viscosity of the
> conventional oil not able to hold up to prolonged high temp running.
> Some folks use an oil cooler, but screen it off in the winter to keep
> the oil from running too cold when the weather is cool. Also
> available are oil cooler thermoststs that only send oil to the cooler
> matrix when it's above a preset temp (about 180 or so -- this is
> sensed outside the sump, where it has already cooled down some from
> the sump temp). With the new synthetic oils I don't think an oil
> cooler is such an issue unless you are running VERY hot, and then you
> probably have other problems anyway.
>
> I've had excellent luck with the Quaker State blended synthetics in
> all my older vehicles. QS's lubrication engineers steered me away
> from their pure synthetic in any car older than 1980, unless I was
> changing all seals on an engine rebuild (same for tranny and axle).
> But they said their semi-synthetic blend could be run with no seal
> problems, and it is very temperature tolerant. As far as rebuild
> theory, I like to run the first 500-1000 miles on a good conventional
> like Valvoline (it's known for its detergent action), then switch to a
> semi-synthetic blend thereafter.
>
> MD
>
> ---Bkitterer@aol.com wrote:
> >
> > For what it is worth,
> >
> > From "The RV Handbook", 2nd Edition by Bill Estes, 1998(?)
> >
> > "Oil temperatures in RV engines usually run 250F to 270F during
> sumertime
> > driving and may exceed 300F on grades in hot weather. . . . Engine
> > manufacturers say that temperatures up to 285F are within their design
> > parameteres."
> >
> > Bob and Annice
> > 1960 Sprite (Mk IV in disguise)
> >
>
> ==
>
> Michael B. Dietsche, P.E.
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