What pressure is the oil pressure relief valve to be set at?

From recent testing by a builder of oil pumps, 3 shims = bad, 2 shims = a bit too high, 1 shim = ideal, no shims = still more than enough to achieve enough pressure. Thankfully, if someone forgets to put any shims in they will be OK.
 
Madnorton said:
From recent testing by a builder of oil pumps, 3 shims = bad, 2 shims = a bit too high, 1 shim = ideal, no shims = still more than enough to achieve enough pressure. Thankfully, if someone forgets to put any shims in they will be OK.
Click to expand...
Do you happen to know why shims are specified for Norton but not Triumph?
 
DennisMo said:
Thanks
Dennis
Click to expand...
According to the workshop manuals, 45/55psi. I assume that this is with one shim but do not know for sure. Since the pump is a gear pump the pressure is quite low at idle and the OPRV is doing nothing until the RPMs come up quite a bit.

I've seen gauges show a max of 60 and a min of 0. Of course, it not really 0, as the same bike with a oil pressure switch set to 4-6 PSI shows that there is pressure.
 
When I rebuilt my engine at 80,000 kms (850MK3) I changed the piston, spring and shim, there was only one and knowing its history it had never been disassembled.
On first start-up, we checked the oil pressure, both hot and cold, and it was OK.

What puzzles me is that on the Andover Norton part-lists for ordering one, they say you need 2 for the 750 and 850 commandos !
 
Great information everyone :) was quite curious about this subject myself, next thing on the Commando to deal with in the morning so a timely question an info :)
 
MKIII No shims and the piston has a nice rattle when you shake it ... On start up the oil pressure gauge runs around to 100 psi . It will take about 10 miles to start dropping pressure . Once hot i have 50 psi at 4000 rpm . Idle at 1000 is 20 psi .
 
andover-norton.co.uk

13.1762

PRESSURE RELEASE VALVE KIT COMMANDO
andover-norton.co.uk

I am using the SRM-06.6195A Oil pressure release valve for Norton Twins.

Norton twin Stainless steel pressure release valve 1960-75 | SRM Classic Bikes

shop.srmclassicbikes.com shop.srmclassicbikes.com


I believe they are factory set at 60 psi. And that is what it shows when I first start it up on my pressure gauge.
It comes down some when the engine is hot which depends of the ambient temperatures of the day.
 
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