When the 24 hour Le Mans spitfire engines were prepared they were built
with -40 main bearings and -30 big ends, the reasoning being that undersize
bearings have a small circumference therefore less drag. So the problem
isn't anything to do with the size of bearings, just the materials and way
the bearings are made. Virtually all bearings now made are the cheaper to
manufacture "Glacier" type where aluminium powder is pressed into place.
Unfortunately the surface of these has a habit of falling off when they are
stressed ie subject to high revs and high shear forces. Vandervall bearings
which were specified for all Triumphs from 1961 have a cast surface, lead
over copper, and this will not come away when abused. The whole position of
which bearings where which became very murky in the mid nineties when both
Glacier and Vandervall were owned by AE (formerly Associated Engineering)
and the subsequent purchase of AE by Federal Mogul has probably made things
worse. There are I think in theory three manufactures of decent bearings for
Triumphs, Vandervall - but they must have a stylised VP on the back,
Glacier - but only with an LC (for lead copper) on the reverse, and an
Israeli manufacturer (King?) sold as heavy duty versions. All these bearings
have a dull lead finish to the bearing surface, all shiny ones are the
poorer quality. Any engine that is going to be subject to high revs must
have the decent bearings fitted, the only problem is finding them.
John Kipping
----- Original Message -----
From: <WEmery7451@aol.com>
To: <fot@autox.team.net>
Sent: Sunday, June 02, 2002 4:00 PM
Subject: 0.020" Crankshaft Rod Journels
> Dear FOTers,
>
> I know that everyone is very busy preparing for the mid-June blowout.
Don't
> worry about it if you do not have time for input to this issue at this
time.
>
> I looked into building up one rod throw with chrome to get back a standard
> size crank, like I use to do years ago. If not feasible, I asked for the
> crank to be taken down to 0.010" under (actually to 0.011"). It came back
> with 0.021" under size rod throws. Have any of you on the list
successfully
> raced with cranks under these conditions. Kas's little black book does
not
> recommend it.
>
> According to my machinist, who builds V-8's for his brother's stock car,
the
> pollution laws have trashed all chroming and nitrite processes in
Pittsburgh
> by outlawing the use of lead. Everything has to be sent to Louisiana. He
> also said that all rod and main bearings have become inferior due to the
> elimination of lead. Some of the bearings have recently improved after
they
> corrected a flaking problem.
>
> Any input will be appreciated. Good luck at Mid Ohio.
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