The V8 Owners Forum -

I have come across a Rover v8 oil pump base and two pressure relief springs in my spares box.
The two springs are a different length so assume one is a high pressure spring, but which one?
Would I be right in thinking that the longer one, would be the high pressure one?

If you measure the diameter of the actual wire in both springs and if they are the same then the longer one will give a higher oil pressure. Provided of course the spacing of the coils is similar in both.

Thanks for that Devonman.
Just for future reference, spring wire diameter is 1.28mm and the free lengths are 71mm (standard spring) and 80mm (high pressure spring).

i dont think that is correct. the standard spring is longer at 81mm and uprated is shorter.... measure the resistance and ask me how i know!

Blimey, you have dug this up from the past. The installed effectiveness of the relief valve spring depends on the preload due to the compression of the spring as it is installed. True, a shorter spring is stiffer but allowance has to be made for the initial installed force on the valve piston.