I recently purchased a rebuilt 2.0 litre air cooled engine for my 82 westy.
Engine runs fine the problem is when I restart it after a few hours of down
time you can here engine knock until oil pressure builds up up(i do monitor
the L/O guage).  Oil pressure is good in all ranges even after reaching
operating temperature she never drops below 10psi. I didnt notice this
problem until I replaced the cold start injector,  because now she starts
right up. I'm using castrol 20w50 an live in southern California, current
temps are 40s-70s. Does anyone have this problem? Is it the pressure relief
valve?
Andy