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GJF GJF is offline
Slantnose from HELL
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Join Date: Dec 2004
Posts: 809
This is a good discussion, I too used oil restrictors until my last engine, and found during the tear down, very odd signs of dramatic wear on rockers and cam lobes. The wear detail on the rocker shafts were worn beyond use, as well the rockers. The cams had abnormal wear on the lobes, the lobes were whithin spec but looked as if there was lack of oil. There were no grooves or failures just extreme wear. This motor had about 80,000 on the top end. So with this current motor I used a GT3 pump and ran -6 lines from the case to the oil towers and no restrictors. I have 6 bar @ start-up and 3.5 bar after warmed up at idle. I also see 6 bar at speed. There are no extra shims under the relief springs (although I did plan on putting some if the oil pressure was too low) and I am running twin turbos with gravity drains to the timing covers. Monitoring the valvetrain while during valve adjustments have shown nicely polished lobes and rocker pads. I would have to say I will never use oil restrictors again. If the oil pressure was too low then a simple shim under the oil pressure relief spring to bring the oil pressure to where I want it. I wouldn't say this is a good bases but one to add.
87 911 Carrera platform
Twin Garrett's, Big Valve, Xtreme Cylinder Heads, JB Racing cylinders and machine work, custom JE pistons, GT2 EVO cams, GT3 oil pump, modified 3.2L intake, 80mm TB, custom Intercooler, equal length headers, DFI, KEP Stage 2 custom twin disc, G50 custom gear set, LSD, Tilton trans pump, Fluidyne cooler
Old 03-23-2008, 12:34 PM
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