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Re: Low oil pressure and different types of relief spring?
Posted: Sat Dec 23, 2017 11:01 am
by Jon Tilson
What i would want to see especially if I didnt trust the absolute gauge reading is the oil pressure building to about 3k rpm and then going no higher as the relief valve opens.
The numbers I would want to see on a sound motor would be no lower than 20 at hot idle and maxing out at 60 psi.
I would try a different gauge of you can.
Jonners
Re: Low oil pressure and different types of relief spring?
Posted: Sat Dec 30, 2017 11:03 pm
by gmsclassics
Thanks Jon, tried an alternative gauge and that gave identical results.
Thinking about the early Jag XK engines that were fitted with a screw adjuster that effectively tightened up the PRV spring so you could set the pressure the spring released at, I dismantled my pump again and fitted a washer below the lower end of the spring. Seems to have worked as the hot pressure at 2650 rpm (60mph in top overdrive) is now 55psi, rising to a peak around 60.
Seeing as I also appear to have at long last managed to seal all the leaks around the pump and transfer housing, I think I'll leave it at that! Pity it isn't as easy as on an XK engine where all it takes is removing a domed nut from the underside of the pump to access the spring - 10 minute job!
Geoff
Re: Low oil pressure and different types of relief spring?
Posted: Mon Jan 01, 2018 2:37 pm
by Jon Tilson
That soubds totally like a result. If you get that sort of pressure then there cant be much wrong internally and the jackshaft side thrust witll be acceptable.
Good job.
Jonners