Need some help - loosing oil pressure at high rpm's

[madmaxx]

[quote=madmaxx;1276563]Thanks. I let you know. Not much progress hope to look at it this weekend. My mentor pointed me towards some interesting information with respect to bearing clearances, oil viscosity shear etc. I also stumbled across some bearing info on the mains which lead me to believe don't know for sure as builder don't have info or won't supply that it may have larger bearing clearances than "usual" when built.

I have no way to measure accurately as I don't trust plastigauge, my guess is the mains are .0025 to .003 as opposed to .002 to .0023. Found a graph on bearing clearance and oil leakage. For every .0005" oil leakage is .5 gpm per main. It was in dart big block main clearance. I know mine isn't a big block but still relevant on increased bearing clearance and oil leakage.

Oh with my new $ gauges which are hyper sensitive drop happen linear from 4 to 5.5k rpm. Not step change, delay was in the dash gauge.

Reducing pressure drop across the plumbing is great but I bet I would just move the drop to a higher pressure. Like 65 psig to 59 psig.

Solution may be heavier weight oil or oil that doesn't shear as easy. Remember we are only talking 6 psig.

This emphasis the need for a builder like blykins who supplies a complete build Manual eliminating the guess work.

With oil warm, 60c, coolant at 80c pressure drop only 1 psig.