Volcom86 Posted September 29, 2019 Report Share Posted September 29, 2019 Hi guys, Bit of history on this motor... Cosworth full long-block with a 2.6L stroke crank. ACL bearings 99.75mm Cosworth Pistons Cosworth Rods Mains pinned Closed Decked Full original Cosworth heads casts and all the Cosworth running head gear. Cosworth oil pump - I am under the impression it is a 12 mm pump in a 10 mm body with 2 shims... Made 350kw on 21- PSI on E85 on a aggressive ignition timing and I had this motor pulled apart a few months later as i started to notice shimmer in the oil... Pulled it apart just in time!!! Bearings were on their way out!!! Old Motor 3rd gear pull on ACL bearings Cold starts i was seeing very close to 100 PSI oil pressure At idle I was seeing low 50 PSI oil pressure at warm idle... WOT pull 80 - 85 PSI oil pressure https://www.dropbox.com/s/2vr7djxl16lo4mr/3 gear final tune1.llg?dl=0 Now that i have a fresh engine and the only difference between the above and now is we used Kings Bearings instead of the ACL ones. Car is making a healthy 375-kw with 25-PSI with less ignition timing... However I have noticed the oil pressure is some what 10 PSI lower then the old motor was producing ... At idle and in the higher RPM range... Now this is on the same oil on both engines.... HPR 10w-50 Full synthetic Cold starts I am seeing very close to 95 PSI oil pressure Idle oil pressure between 38 PSI - 45 PSI once warm WOT pull 73-75 PSI WOT pulls 2nd to 3rd https://www.dropbox.com/s/ciba3ixc2p3dzni/cruise 1.2.llg?dl=0 Oil Pressure sensor is in the same location as always and running a stock oil cooler so no change. Is this something to be concern about? Quote Link to comment Share on other sites More sharing options...
oversteer Posted September 29, 2019 Report Share Posted September 29, 2019 Cut your oil filter open and look. Those pressures aren't that bad/low, what were your bearing clearances ?, the question is has it changed since this motor was in, any decline ? You of course used a new oil pump after previous bearing failure ?? Quote Link to comment Share on other sites More sharing options...
JMP Posted September 30, 2019 Report Share Posted September 30, 2019 I'd 2nd the bearing clearance question Quote Link to comment Share on other sites More sharing options...
Volcom86 Posted September 30, 2019 Author Report Share Posted September 30, 2019 Yes we have cut open the oil filter and all looked normal few microscopical elements as to be expected after its full run in... Oil pressure has not changed since started... Seems like they are a ted on the looser side... Mains were from .0011 - .0014 Rods - .0021 - .0022 Quote Link to comment Share on other sites More sharing options...
oversteer Posted September 30, 2019 Report Share Posted September 30, 2019 If it hasn't changed it should be fine, however I would consider your bearing clearances tight for a high-ish hp performance motor, cosworth assembled long block would have been looser. Quote Link to comment Share on other sites More sharing options...
Brad Burnett Posted September 30, 2019 Report Share Posted September 30, 2019 How high are you reving the engine? If only going to 7-7500 rpms, then you should be fine. But if your winding it out to 8-9k then you may have some concern. You typically want roughly 10psi for every 1000 rpm. Ive built many subaru engines. Most would be around .001 on the mains and .0015-.0018 on the rods. Did you reuse the oil pump from the first motor? Did you inspect the internals of the oil pump? Quote Link to comment Share on other sites More sharing options...
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