[TR] Oil Pressure 102

[Bob]

On Friday 14 November 2008 23:55:51 John & Pat Donnelly wrote:
> In speaking of oil pressure, all the TR's I've seen tend to have lower oil
> pressure as they warm up. Now I understand that heat causes metal surfaces
> to expand, and so I can understand some pressure drop. But I've seen a
> 30-40 lb drop running from cold to hot. Is such a drop indicative of a
> "worn" engine? What should be expected? My modern car has an oil pressure
> gauge, but it doesn't vary by much. Why do TR's?
>
>
>
> Does running at a higher than recommended 70 PSI cause problems? Why the 70
> PSI and not something else?
>
>
>
> It was mentioned in previous emails that internal engine air pressure would
> affect oil leaks at the rear seal. If your car "leaves it mark" via the
> rear seal should internal pressure be suspected?
>
>
>
> Thanks!
>
> Johnnie
Johnnie,

Before I had my 3 engine rebuilt by Matt Bates down at the Triumph Rescue, 
that is how the 3 engine's oil pressure would be.

Starting up from cold, it would be 75 pounds but after the temp ran up to  the 
middle, at idle it would be around 10 maybe getting up to 40 at 3000 rpm.

After the rebuild, the pressure is the most constant I have ever seen in this 
engine. It is 70+ at 1000 - 3000 RPM. 

I have the idle set to about 800 - 900 and even in the dead of summer the 
pressure never went below about 65 at idle.

I am running Brad Penn 20 -50 racing oil + 1 bottle of STP 4 cyl oil treatment 
as advised by Matt.

The engine was broken in with Brad Penn 30w break in oil with the same oil 
pressure readings.

I rebuilt the engine in the 4 as it required a bit less effort and using the 
same oil and treatment and its readings are only about 5 - 10 pounds less at 
idle than the 3. But it never goes below 55 or 60 at speed after warm up.

Both engines have the stock oil filter with no oil coolers. Stock cooling 
systems with a 165 degree thermostats.

Bob