My comments below apply to stock Rover V8s as installed in TR8s, SD1s and
3500Ss.
----- Original Message -----
From: "Susan and John Roper" <vscjohn@huntnet.net>
> Actually, 8-10# at idle at operating temp would be quite acceptable.
Rovers, SD1
> and later(Ihave no recent experience with pre-SD1 stuff) will not make 30#
at idle
> unless there is something unusual in the oiling system.
Not true, unless you mean that SD1 and 3500S dash panel gauges are
inaccurate. Dead stock SD1s will sit right around 28-30 psi within about 15
seconds of startup. I currently have this on an unrebuilt engine with
around 150k miles on it. This is with the specified 20W50 oil.
> A 3.5L TR8 engine that I
> recently sold would make 25# at cold idle, stock 70k engine, but at
normal temp it
> was down to 10 as expected.
Better take a poll on this one. Just about everyone with a V8 on the
Rovernet mailing list would be very concerned to see only 10 psi at idle,
and every buyers guide for production Rovers would advise you to walk away
from a stock Rover engine with those readings.
> Be cautious about using high viscosity oils. The gear
> drive has known limits and attempts to make the system produce high
pressures can
> lead to failure.
Rover has always specified 20W50 for this engine, and I've never seen a
specialist recommend anything else. Even using 10W40 will have a definite
effect on your oil pressure. You will see lower oil pressures, especially
at higher temperatures. Also, since we all know that the oiling system of
this engine is a bit marginal, it makes more sense to use an oil that leaves
more of a film on the moving parts for the next startup.
It's the attempt to increase the oil pressure that put a strain on the oil
pump drive, not the oil. It was designed for 20W50. Personally, I use the
oil specified by the OEM, and my oil pressure within falls right in where it
should.
> The system is designed to move volume, not make pressure.
This is true. It is designed to move 20W50 at reasonable volumes through
oilways designed for that oil. My impression is that the oil pressure will
drop with a thinner oil because it squirts through those 20W50-sized
openings with less resistance than 20W50 does, but I don't know that you
would gain anything in volume and the oil will provide less protection when
it gets there.
> My experience with bottom ends for the race car carefully assembled with
components
> properly machined, flow restrictors in the heads, relieved passages in the
block,
> and a pressure regulator on the relief valve resulted in some very high
cold idle
> pressures, which dropped below 20# at temp. John
It's important for everyone reading this list to bear in mind that a lot of
the numbers tossed around on this list are for decidedly non-stock engines.
There is a definite mix in the readership of this list of people coming from
a stock engine perspective (like me) and mechanical wizard hot rodder types
(like maybe John). As soon as you modify these engines from stock, the oil
pressure and other readings may change, but they are only normal for that
engine or other engines modified in the same manner. What's optimal for a
racing engine most likely isn't normal for a stock engine.
By the way, who is this Bozo Larry Hoy who started all this controversy,
anyway? ;-) ;-)
(Lots of smileys, Larry...)
Glen
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