Oil Pumps

[Mike Wattam <MikeWattam@domain.elided>]

Hi Al

The oil pressures you describe on your Stag are normal, 40/50 cold and
15/40 hot.

Don't worry that your pump is not marked Hobourn Eaton, they are made by
Associated Engineering anyway and usually have an AE symbol on them !!!

I'm afraid oil pumps, bearings and oil pressures is a complex subject.  You
should only get concerned if there is a distinct change in the behaviour of
the guage, such as a drop from 40 hot to 20 hot at speed.

In general terms, higher pressure in a fixed system indicates a low flow,
and vice versa.  If I had a Stag with a very high oil pressure, I would
really worry.  I have known engines (e.g., Rover V8) that go on for years
with zero at idle and 20psi under load, yet producing 250hp plus.

This is why oil pressure guages are an almost complete waste of time (waits
for flood of replies).

Mike Wattam
Trumph Stag Register.