GT6 Spitfire oil pressure gauge readings?

[karls59tr]

What kind of oil pressure reading should the gauge show after a hard run? What is considered too low a reading...one that would indicate a serious problem? Same question for the GT6.

 

[dklawson]

Well... there are the technical answers and the feel good answers.

As you have seen, after a hard run the pressure will be lower. The grade of oil you use and engine temperature all affect this as does your idle speed. I believe the hotrod guys (not Triumph guys... just regular gearheads) used to say minimum 10 PSI at idle and 10 PSI for each 1000 RPM up from there until your relief valve opens. The Spitfire/GT6 oil pressure warning switch doesn't come on until about 5 PSI so if you see it... you really have problems. Personally, I would like to see 30 PSI at idle but on hot summer days I am sure our car will hover closer to 25 PSI with a 1000 RPM idle and 20W50 oil. You can improve that by having an efficient cooling system and perhaps adding electric fans.

I am sure others will have their own preferences and observations on normal oil pressure. I have never seen any factory limits for these engines. Hopefully someone will post those numbers if such values exist.

 

[3798j]

This from the Haynes Triumph GT6 & Vitesse workshop manual:
Note: Low oil pressure in a high-mileage engine at tickover is not necessarily a cause for concern.
Normal oil pressure at 2000 rpm.........40 to 60 lbs.

 

[Andrew Mace]

And Jay's quoted numbers are about the same for a Spitfire engine. It'll look just that much better (closer to the 60 psi) in warmer weather with 20W-50 in the crankcase. I also concur with everything Doug said!

 

[number6]

One thing I've found is that individual gauges are not all that consistent. I installed new smiths gauge in my 79 Spitfire and on start up pressure is in the 80's. Thinking that was very high, swapped it for an older gauge I had and on start up
never got above 60. After a hard run low side was 20 and 30 respectively
Number 6
79 spit, 67 rover 2000tc 69 mgc sunbeam harrington 04 jag x type