<VV> Conventional, Synthetic Blend, Full Synthetic

[RKHenry]

For my turbocharged Corvair, I think that there's no other choice. The oil
really gets cooked in the bearing area of the turbo and an oil that can
stand up to that is essential. When I overhauled the turbo I found out what
can happen with conventional mineral oils--they just break down into coke,
clogging everything. 

For similar reasons, I think that synthetic is a better choice for any
air-cooled engine because of the temperature ranges that it can encounter.
Finding piston rings glued into their grooves is also convincing.

Switching to Mobil-1 after break-in was complete and after trying other
oils, I found that with synthetic, gas mileage improved by 10%, oil mileage
doubled (about a quart in 1,700 miles), and I calculated at the time that
those improvements could pay for the added cost of the Mobil-1. Preserving
scarce, valuable Corvair parts from wear would be another advantage, though
I have no direct evidence of improved engine life.

I had a couple of occasions to open the rocker box for repairs (dropped
valve seat and again for failed valve seals). The engine had been scrubbed
clean as a whistle during overhaul but during break-in it accumulated a
heavy patina of varnish all over the rocker area. After a few thousand miles
of Mobil-1, the synthetic had cleaned up most of that varnish. I'm
convinced.

I did find that the "high-temperature" valve gaskets that Clark's sold me
softened into sticky goo. I replaced them with ordinary valve gaskets from
my local parts house and they works fine. No sign of other seal
deterioration with synthetic. The vibration damper at the rear has seeped
slightly since day one but it was already worn and I probably should have
replaced it when I replaced the rear seal.

I'm also using synthetic gear lube and synthetic grease I bought from
Clark's. No problems.

So I've also decided to run my non-collector Saturn on Mobil-1 as well. It
just runs better. I don't add oil to the Saturn, I just change it when it's
down a quart--about 5,000 miles.

I haven't tried other synthetics in cars but I fly with AeroShell 15W-50
semi-synthetic and get similar results there. I advocate synthetic
lubricants for almost all applications.

An engine which is being held together by varnish and dirt which might be
dislodged by synthetic oil ought to be overhauled anyway--to preserve the
valuable parts if for no other reason. Continuing to run a gunked-up engine
will accelerate wear on these hard-to-find parts. If dirt is keeping oil
from going where it's not supposed to go, it's probably also keeping oil
from going where it's supposed to go.

Bob Henry

> -----Original Message-----
> From: virtualvairs-admin@corvair.org [mailto:virtualvairs-
> admin@corvair.org] On Behalf Of Vukas, Robert
> Sent: Friday, January 07, 2005 12:17 PM
> To: virtualvairs@corvair.org
> Subject: <VV> Conventional, Synthetic Blend, Full Synthetic
> 
> What do any of you know about introducing synthetic blend oils or full
> synthetic oil to our collector cars? The rumor mill would tell one that
> through the years an old car would have its' seals cleaned out and leak
> in a big way if synthetic oil was introduced to the system. The false
> seals would give way to big trouble. Now, my car friends are telling me
> that if one continues with the process that eventually the engine would
> seal up again,in time,with the continued use of  synthetic oil.
> 
> My question is this: Is it worth using synthetic blend or full synthetic
> oil in our collector cars for the added protection?