Oil starvation issues SBC HELP?

[joespanova]

Originally Posted by carl hinkson

If your using a cheap bore gauge with rigid fingers your not going to get a correct clearance. Not to many guys can afford good bore gauges to check bearing clearances.

Here is a thread on different bore gauges.

http://www.performanceboats.com/gn7-...learances.html

Carl , as a machinist for the last 35 years and in particular at a major airline ........we don't use / have any "cheap" bore gauges.

[Mike Taylor 3601]

If nothing else try 10550 pump or another that uses 5/8 pickup tube,it fixed a couple engines for me.
That Ultimate II is still good pan that stroke with alum rods shouldn't have any windage issues,we ran that same pan on 9,500 and 10,000 rpm engines with that long of stroke and aluminum and steel rods.
Is pan like Moroso made it?It hasn't been modified or left anything out of it ?
Not overfilled on oil?

I remember first time we used one of those pans we like to never got it on the engine and got in the car and had to pull it for some reason and we thought crap this is going to be bad, with engine sitting right side up it falls off engine,when engine is upside down that pan is virtually impossible to get off or on,so if yours goes off and on with engine upside down may have parts missing.
If remember correctly has teflon coated tray that is practically solid no holes or louvers,and it directs oil it catches into the kickout,only part of pan you can see bottom is area where pickup/pump sets and rest is hidden by windage tray.
with 30wt. and HV pump .0025-.003 clearance should'nt cause issue,those clearances and that pump you should have 60-80lbs oil pressure cold and probably 50-60lbs with 170-190 oil temp idling and when rev should go up,if drops instead it is cavitating from pick up clearance too close or far away,or 3/4 pickup or windage.

Don't assume anything is right out of the box.

Mike Taylor 3601

[joespanova]

Mike this pan hasn't been modified. The 10552 c pump is whats in there now with the .750 bore/ tube.
I had a HV55 with a .625 bore...............same problem
It may well BE the vac pump. I'm going to reduce vac , baffle the pump and very likely add an accumulator.
Moroso changed the Ultimate 2 apparently , because mine has a big kick out with tubes going through it ( 3 ) and a SCREEN not a baffle..........and it came this way new in 2001 or so.

[pmrphil]

Did you have the pressure drop problem on the first run also, or just the second? What kind of pressure did it carry on the first run? Where is it starting to drop (RPM, gear, how far down the track, etc.) and how far does it drop? From what to what? As much detail you can provide will give everyone looking more to see and quite possibly touch on something someone else has seen.

[joespanova]

Originally Posted by pmrphil

Did you have the pressure drop problem on the first run also, or just the second? What kind of pressure did it carry on the first run? Where is it starting to drop (RPM, gear, how far down the track, etc.) and how far does it drop? From what to what? As much detail you can provide will give everyone looking more to see and quite possibly touch on something someone else has seen.

I dont have a data logger...........I can't answer that question
.'
All I can share is that it dropped after the second pass. Historically that symptom equates to damage. I trailered it after that.
From what I can conclude "
A tray is better that a screen
I may need to reduce vac
I will baffle the pump as best I can
I may very well add an accusump / accumulator

[L79racer]

What crank is in your motor? I had a very similar problem. ruined motor twice. Kept loosing pressure. Thought it was aerating oil. Tried more, then less oil. changed pump, pickups, restrictors no restrictors etc. Finally got new crank and it solved the problem. I had an eagle crank that was crossed drilled from 2006. Machine shop said that they didnt do that anymore. New eagle crank and no more problem. Sounds crazy but everything else in motor was exactly the same.

[Peter Ash]

A good read on cross drilling crankshafts in high rpm engines.

http://rehermorrison.com/tech-talk-5...calls-part-ii/

[joespanova]

Originally Posted by L79racer

What crank is in your motor? I had a very similar problem. ruined motor twice. Kept loosing pressure. Thought it was aerating oil. Tried more, then less oil. changed pump, pickups, restrictors no restrictors etc. Finally got new crank and it solved the problem. I had an eagle crank that was crossed drilled from 2006. Machine shop said that they didnt do that anymore. New eagle crank and no more problem. Sounds crazy but everything else in motor was exactly the same.

Its a BRC 4340 3.48 crank.
Its not cross drilled.
It seems like the answer is:
Std pressure pump.
A well thought out windage tray / pump baffle.
Reduce vac pump vac level.
and for me anyway , adding an accumulator just because.
I'm pretty sure the first 2 are the "focal point" for any good SS engine.