Oil pump shim

[Rawze]

(05-20-2017 )slowpoke Wrote:  just fired it up after it letting it cool and same thing started, if i let it idle at 600 rpm pressure actually comes up to 38psi, increase idle to 850 pressure starts to drop down weird. Well i guess i'll wait till i go down the road and see what happens when it gets heated up, just don't know what else can dump oil pressure then return to normal. If pressure is good going down the road then i'm going to try a thinner synthetic, maybe.

If mine went haywire like that after doing a mod to it, I would find out why. Perhaps your shims are in the wrong place,.. or have gotten lodged where they should not be. Not worth the entire engine failing to go monkeying around like that without knowing 120% what you are doing. Besides that, anything much above 45 PSI peak or so, and you are looking at the fly-wheel housing having high risk of leakage on an older engine. To fix it, you are looking at removing the tyranny and doing a lot of work to replace that FWH gasket if it fails because you are pushing oil pressure up so high.