Do the concourse guys take points off for synthetic use?
JR
----- Original Message -----
From: "Bob Spidell" <bspidell@pacbell.net>
To: "healeylist" <healeys@autox.team.net>
Sent: Thursday, September 09, 2004 6:59 PM
Subject: Re: BJ8 Oils?
> Jon,
>
>
> re:
> "Be careful with modern lubricants in your transmission and O/D they seem
to
> have a lot of sulfides which are very bad for any yellow metals ie. brass,
> bronze etc. They can cause the yellow metal to be eaten or dissolved and
> can then clog the small passages in the O/D."
>
>
> I don't believe you should make such a generalized statement about "modern
> lubricants." I know this is true for hypoid gear oils, the sulfur coming
from the EP
> (extreme pressure) addititives (you can smell the sulfur). Never used it
in a Healey
> gearbox, never would. I don't believe engine oil has any sulfur-based
additives,
> most use star-polymers for viscosity improvers and zinc for anti-scuffing,
added to
> either synthetic or mineral base stock.
>
>
> re:
> "Which is why a 30W non-detergent is originally called for ..."
>
>
> Called for by whom? My Bentley reprint of "The Complete Official
> Austin-Healey 100-Six and 3000 1956-1968" manual calls for the same
> oil to be used in the engine AND gearbox; listing several brands of 40W,
> 20W-40 and 20W-50 (lighter weight multi-vis for lower temperature
> ranges). My Dad's BN2 manual calls for 30W non-detergent ... of course,
> they didn't have (much) multi-vis in 1954. Looks to me like the Austin
engineers
> learned a few things over the years.
>
>
> re:
> "... so small particles would settle out and not kept suspended to get in
the way."
>
>
> I don't buy the "particles-settle-out-is-a-good-thing" theory. If your
gearbox
> is making big chunks of iron letting them settle out won't make much
difference--
> you're hosed. I figure the minute particles of brass suspended in the oil
won't
> cause any problems, after all brass is a soft metal--effectively its own
bearing--and
> soft, finely ground metals (lithium, molybdenum, etc.) are used as fillers
in the best
> greases. Letting your gearbox sludge up because that's what they did in
1950 doesn't
> make sense to me ... what happens when a big chunk of sludge goes on
walkabout
> and enters your O/D valve port? Besides, the small brass screen and the
magnetic
> washers in the O/D should get any small flakes of iron or steel ... what
happens when
> you've sludged-up that screen and the oil can't circulate through it to
the washers?
>
>
> MT90 is a full synthetic and doesn't contain any sulfur compounds. The
RedLine
> people discuss their technology at length on their website. It hasn't
dissolved my
> gearbox yet, but I've only had it in for 4 months and 5,000 miles ;)
>
> As for using synthetic in the engine, the Crower comment is the first I've
seen to
> indicate that syn has lower shear resistance. They are a well-known and
credible
> manufacturer of cams, bearings, cranks, etc. so I figure they know
something.
>
> As often as we (should) change our engine oil synthetic doesn't seem like
the right
> call in the engine.
>
>
> bs
>
> ********************************************
> Bob Spidell San Jose, CA bspidell@pacbell.net
> '67 Austin-Healey 3000 '56 Austin-Healey 100M
> ********************************************
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