<VV> Which OIL? Re: Doc opinion
RoboMan91324 at aol.com
RoboMan91324 at aol.com
Wed May 20 01:45:55 EDT 2015
People use dino oil in a newly rebuilt engine to hasten the break-in
period. It may not hasten break-in by much but this is debatable. Another
reason for using dino oil during break-in is that you will have a couple of
very low mileage oil changes. Notoriously frugal Corvair people hate to throw
expensive synthetic (syn) oil out when dino oil will do for break-in. Of
course, considering your catastrophic results, throwing away low mileage
syn oil would have been economical if it would have saved your engine and
allowed for a more pleasurable vacation.
Regarding syn oil being used in modern engines right from the factory,
those engines are not our engines. The materials and surface finishes of
cylinders, rings etc. on modern engines result in engines that are essentially
broken-in upon delivery. Unless people on VV who are smarter and/or more
experienced than I tell you different, I would break-in the rebuilt engine
with dino oil and then switch to syn. This assumes that you can perform the
break-in mileage as gently as possible. No fully loaded mountain climbing.
Your experience was the perfect storm that led to engine failure. The
heaviest vehicle to normally include a Corvair engine (an air cooled engine
notorious for heat generation); dino oil which loses viscosity and
lubricating characteristics at severely elevated temperature; an extra heavy load of
people and vacation supplies; running the UV uphill for an extended period.
Under those conditions, maybe the syn oil wouldn't have been enough.
Certainly, it would have helped.
There may have been other issues including timing. You may have had the
timing adjusted well enough to avoid knock during the several unloaded short
trips you referenced but was it timed to prevent knock at low speed, under
heavy load, uphill and with elevated temperatures. Did you have a knock
Lastly, you say the damaged parts included pistons and cylinders but you
did not talk about anything else. If the failure of those parts was due to
degraded oil, I would be very concerned about the bearings and even valve
guides, lifters, cam surfaces, push rods, rockers, etc. I know it is a PITA
to tear your engine apart unnecessarily but it is better than rebuilding
the top end and discovering a complete rebuild was necessary after
everything is "buttoned-up" and back in the UV. .... and during your next vacation.
You may have considered all of the above but, as always, I am writing both
to an individual as well as to benefit others.
'60 Corvette; '61 Rampside; '62 Rampside; '64 Spyder coupe, '65
Greenbrier; '66 Canadian Corsa turbo coupe; '67 Nova SS; '68 Camaro ragtop
PS: To answer your question, I use 10W 40.
In a message dated 5/19/2015 7:29:56 P.M. Pacific Daylight Time,
virtualvairs-request at corvair.org writes:
Date: Tue, 19 May 2015 16:54:01 -0700
From: "Bob" <bgilbert at gilberts-bc.ca>
To: <efki at verizon.net>, <james.f.burkhard at delphi.com>,
<frankcb at aol.com>, <corvairjack at yahoo.com>, <virtualvairs at corvair.org>
Subject: Re: <VV> Which OIL? Re: Doc opinion
Content-Type: text/plain; charset="UTF-8"
Now this is both interesting and timely. I am one of those under the
impression that you needed conventional oil for the first few hundred miles.
Are we now saying that I can put synthetic in a freshly built engine like
the 3.1 I am putting together for my UltraVan?
If so, what weight?
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