casper50 Posted July 17, 2018 Report Share Posted July 17, 2018 Since I've been driving the coupe I've had weak oil pressure readings. Really weak. I even changed the oil to straight 30wt as that's all that I could find here. I bought a new oil pressure relieve valve spring from Andy B and just installed it. It's now too high. Will have to change oil again. When warm I'm getting 30lbs idle at 450-500 rpms and when driving anything over 35 mph it's at 70lbs. The photo shows the spring that I put in on the right, the one that I took out in the middle and the short one is an extra that Andy sent since he said that it could take either. the original that I took out is shorter and looks to have been streched. Still didn't do the job properly. 1 Quote Link to comment Share on other sites More sharing options...
Merle Coggins Posted July 17, 2018 Report Share Posted July 17, 2018 That spring on the right looks to have a bigger wire and more coils. Also, the coils are so close together it looks like it wouldn’t take much compression before it coil binds. And the left one is certainly too short. Could you put a washer, or 2, between the original spring and the plug and try it that way? That’ll increase the spring tension for you and should increase the pressure setting. 2 Quote Link to comment Share on other sites More sharing options...
Dodgeb4ya Posted July 17, 2018 Report Share Posted July 17, 2018 The oil pressure relief valve spring generally only controls (limits) max oil pressure at higher RPM's once engine is completely hot. At a slow hot idle on the flatheads the oil pump is not generally capable of pumping enough oil thus bypassing oil to the sump via the pressure relief valve and spring. Oil type, weight and grade can affect the pressure regulation as most already know too.? Quote Link to comment Share on other sites More sharing options...
DJ194950 Posted July 17, 2018 Report Share Posted July 17, 2018 9 hours ago, Merle Coggins said: Could you put a washer, or 2, between the original spring and the plug and try it that way? That’ll increase the spring tension for you and should increase the pressure setting. Not to sure about this but adding washers where used in hydraulic oil systems on equipment I used to work on, but-- my Plymouth repair manual 1949-54 says- DO Not add washers/ball bearing under the pressure relief spring to attempt to raise oil pressures. Try a new spring that matches your original. Different springs where available by color, red=light spring, medium is unpainted and heavy spring is green. I doubt replacements are painted at all but not sure. DJ Quote Link to comment Share on other sites More sharing options...
casper50 Posted July 17, 2018 Author Report Share Posted July 17, 2018 there's no ball bearing in my relieve valve. Quote Link to comment Share on other sites More sharing options...
DJ194950 Posted July 17, 2018 Report Share Posted July 17, 2018 3 minutes ago, casper50 said: there's no ball bearing in my relieve valve. That was something mentioned in the repair manual. I never used a ball bearing for that purpose and Not used in the stock relief valves in these motors that I know of. ? DJ Quote Link to comment Share on other sites More sharing options...
casper50 Posted July 17, 2018 Author Report Share Posted July 17, 2018 okay understand it now. Quote Link to comment Share on other sites More sharing options...
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