Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing plus 8 oil pressure

I am not happy with the (apparent) oil pressure on my new plus 8 engine. It is about 35psi when warm at 3000rpm, and that is just OK. The problem is the apparently zero pressure at idle when hot.
I believe the pump is inadequate and I'm looking to fit the new front cover and crank driven pump (John Eales http://johnealesroverv8.co.uk/3.html.) I believe my crank is suitable.
Has this been fitted by people here, and if so what difference did it make?
Thanks
Terry

Are you sure it's not the gauge/sensor?

Good question - maybe I should get a new gauge first. I tend to believe it because the high pressure is more or less as expected. The engine doesn't rattle at idle, so there is oil to the hydraulic lifters. Oddly, my car has no oil pressure warning light or switch (I think they are set for about 7psi on other Mogs).

Anyone know a good place to get sender/gauge?
Terry

I would default to Brands Hatch Morgans or Melvyn Rutter in the UK....of course there may be/are others....no link.

when I say sender/gauge I have made a small error. I should mention that it is a mechanical gauge so the sender part is a bit of tubing

There is no sender switch showing low oil pressure, and no oil light. I don't know how common this is in Mogs (1982 plus 8). Has my warning light been abandoned by a previous owner ?(when fitting a new dash)

I've always believed the +8 has fairly low oil pressure.

Lack of oil pressure when hot, can be a issue with some oils and ones for modern engines are certainly thinner. You've not said what you are using, so what? Probably can be ruled out, but best to check.

Oil lights are almost useless. If the oil light illuminates while driving, with most cars, it's a 'change the engine now, as you just wrecked the current one' light. Far too low a pressure. I changed the light on Woodstock for a 25psi switch, if that lit, the engine might yet still be saved.

35 to 40psi is ok for a standard engine. It is possible to put in an uprated relief spring which will take it up to 50psi from memory. Key thing is to keep the oil clean, I used to change my annually even when only doing low miles.

I upgraded my timing cover from an uprated SD1 type with tadpole pressure release and direct distributor / timing gear oil feed for an early serpentine timing cover with distributor. The serpentine oil pumps are crank-driven and raise the pressure to circa 50 psi at 3000 rpm. Raising the oil pressure on the early pumps increases the wear on the distributor / timing gears as the oil pump is driven from the end of the distributor.

Fitting a serpentine timing cover will require the slot for the crankshaft pulley woodruff key to be machined longer.

Hope this helps Terry. Regards, David.

Terry, what Oil are you using, viscosity can change dramatically with some oils when an engine gets hot and then loss of pressure can occur. I have used Fuchs 5-40w Pro-Race Ester Fully Synthetic in my 4l +8 and this was very stable across the heat range and in fact the engine ran at about 5 degrees cooler, however I was advised to use a 20-50w Synthetic as makes quieter running when hot, and now use Valvoline 20-50 fully synthetic, pressure is up a bit but not as good on temperature. If you can find a fully ester synthetic 20-50 then you will get good results.

You say your engine is new, so no pressure at hot tick over is odd, sounds like the gauge, and/oil combo.

Let me know how you get on.