Hi all, Does anyone happen to know at what pressure the Oil control valve opens in a dual-relief case? This is the valve which limits the max oil pressure, once hot, as opposed to the relief valve, which bypasses the cooler, when the engine is cold. I've fitted a random sender & gauge (from my random ACVW parts stash), which reads around 3bar max, when hot, increasing to a little over 4bar during warm up. I'm not bothered whether these figures are accurate or not...I only keep an eye on whether the gauge is reading 'different' from normal. That said, I'm just curious to know how (in)accurate the reading actually is... Cheers Paul
As far as I'm aware, the relief valve pops off at 3bar/42psi. Your oil pressure shouldn't go higher than this.
My new engine seems to sit around 45psi max when running .. so I agree. A good thumping cold start at -3 C and I got over 105PSI once or twice with a 26mm pump with the old engine. Even if the plunger lifts the pump can build up some pressure before the treacle moves.
On a link note, yesterday I set off from home all running well country roads then on to mains, I have a VDO oil pressure sender 0-5 bar with indicator dial in cab. Anyway oil pressure was up and kept going up the faster I went showing 4 bar at 40 mph. Not happy, slowly ran back home cancelling the appointment, every thing else ok have oil temp dipstick and cylinder head temp both fine but worried headed for home. Underneath this morning took out and checked both control valves, oil control a bit scored so polished with wet and dry but generally ok, not stuck both dropped out easily but not slack, took her for a test run, no change. Only thing to do check pressure sender, luckily have a 0-10 bar VDO sender in the cupboard so swapped them out and all is now A ok albeit reading half value but better than paying out £60 on a new one. That little episode had me worried but it looks like the dial in the cab was reading mains volts and not the sender output as the sender was knackered. A bit of a head scratcher that I hadn't heard of before so just letting you know. 73 bay Devon by the way 1600 twin port, had her 27 years and never come across anything like it before. 10 psi per 1000 RPM sounds pretty good to me
