Normal rod and main bearing clearances only drip oil when supplied by a 30 psig charged oil (prelube) pressure pot, with engine off..
A big oil leak will show up instantly with a 30psig prelube pot.. You would hook the pot up, turn it on and try to see where it comes pouring out of.. that’s where your problem is.. same as trying straight 50w oil, if it doesn’t raise your pressure you’ve got a massive internal oil leak..without rod and main bearing clearances it’s a swag…(scientific wild ass guess)…
Just to clarify, the reason for trying this would be the increased pressure needed to overcome the bearings, therefore revealing a potential leak somewhere else? If it doesn't leak anywhere but the bearings at 30psi then those would likely be the issue, correct?
Sounds like a decent plan to me! Do you guys have any suggestions for a pump that's decently cost effective? Not sure if a usual hand pot could build 30psi.
When you wrote, “I replaced the head jets, O-rings, and that tiny…….”
Are you referring to the camshaft oil restricting orifices…?
Yes - I tried to pay extra attention to vital o-rings.
Bill, I've seen some of Steve Morris's stuff - guy builds some crazy engines!
Yes, “I replaced the head jets, O-rings, and the tiny…..”.
Or Yes, “I replaced the head jets’s o-rings, and the tiny….”
The sprayer will bird shows would be more economical than what I use..Mine is similar to a pressure brake bleeder without the rubber bladder because it holds 6 quarts if you fill it up..
If I was doing it. I would be interested in obtaining a higher cold pressure than your 10psig running pressure.
For instance if you turn your pressure pot on and you instantly get 30psig on your engine’s oil pressure gauge and it holds steady while the oil in the sprayer tank slowly flows through the engine rod and main bearings and oil jets, then I would say your pump can’t pump..
But however, if your oil pressure gauge never indicates any thing over 10psig and the oil in the sprayer tank quickly drains out the engine’s sump, a new oil pump is not going to correct what’s wrong…
You’re looking for instant sprayer tank oil flow and rapidly falling sprayer tank pressure. And a leak or leaks so big your engine’s oil pressure gauge can never get close to the sprayer tanks feed pressure.. It really doesn’t matter the starting pressure..good tight bearings don’t leak much, your watching for how fast and how soon oil starts coming out of the sump. Even the cam shaft restrictor jet’s oil has to pass through the camshaft bearing journal’s first..this all takes several seconds before any considerable amount of oil starts flowing out the sump.. A big leak or leaks will leak instantly..
The 50w oil was just a suggestion you could try to determine if your oil pump and/or your rods and mains are worn out. The 50 weight should give you a higher initial pressure until it get hot, it’s really a lot thicker than a 10winter rated oil when cold.
It’s hard for members to initially determine your engine experience and no one wants to be condescending. When you post “everything looks good or fine” when someone asks about your clearances, we first assume you’ve checked them and they are “good” or “fine” and within the service manual’s specifications.
The 70w oil usually is used in nitromethane/alcohol engines that suffer from, as willbird indicates, structural stability as well as from oil dilution from fuel contamination..They burn that much fuel in 4 seconds and need whatever cushioning may be available from big clearances and very thick oil.. Most of that type of engines get their oil changed every pass..
PS I would not hook the pot up to the scavenge port that feeds the transmission. Engine supply port only..
