allblowdup

I have a weird one. A crate lsx454 620 hp version with a dan olson jet boat oil pan. Oil pressure is fine cold and hot at idle and cruise rpms up to 4500. At WOT (5700) the oil pressure starts to fall after a second or two. It goes from 50+ to around 37 and kinda bouces around there. When you slow it down it does not come back right away but takes 4-5 seconds. One weird thing is that the dan olsen oil pan has a screw in dipstick about 4" long in the middle of the pan and it was left loose by accident. It came out and the weird thing is that at less than 4500 rpm very little oil would come out of it but at Wot it became an instant gusher and stopped as quickly when the rpms fell back below 4500. I am pulling the pan off anyhow to have a look but was wondering if anyone has any ideas what I should be looking for. I did have to remove tha factory windage tray but the dan olsen pan has one biult into it.

LSXNV

iTrader: (1)

I lost two engines that had a similar issue. What I ended up finding out was that the oil was not getting back to the pan quick enough and allowed the pickup to be uncovered. And the pan was not large enough to make up the difference with extra oil. We fixed it by opening up the oil drainbacks and using a larger oil pan. Bear in mind though this was in a traditional Pontiac.

Gray86hatch

iTrader: (83)

Look at your pickup tube the screen might be too tight. how many quarts do you have in it?

What pump do you have on it.

Tim

allblowdup

Pulled it apart last night. It holds 8 litres the oring on the pickup tube is good. I have 1/2" clearence to the bottom of the pan. I am thinking that windage could be causing it. I had to remove the factory windage tray in order to have room for the pickup tube. OIl pump is factory GM unit.

Gray86hatch

iTrader: (83)

Pick up tube is too far from the pan. Grind the tray to make it fit

Tim

thompson

iTrader: (4)

That is really common with high volume pumps, What pump are you running?

Gray86hatch

iTrader: (83)

The inlet side needs help.
I get my pumps and pickups from car shop inc and have no issues with oiling. They have tested theirs at the Texas mile and they are not running into problems.


Tim

allblowdup

Standard volume gm unit. 1/2 from the bottom I would think would be ok. The pan is deep. Definately know that the pickup was not getting uncovered from not enough oil. but ya i think the windage was wipping the oil to the sides.

427

iTrader: (3)

The pick up should be 1/4-3/8 max from the bottom. Do what you must to get the windage tray back in.
What kind of vents are on the valve covers?

Kurt

allblowdup

t has pan ovacs to the headers. I swapped out the oil pan last night to ct525 oil pan and was able to reinstall the windage tray then. The ct525 pan also has a biult in oil slosh tray in it. pickup is 3/8" away from the bottom on this one. If this doesn't fix I have no idea what will.
So what is the issue of having the pickup more than 3/8" from the bottom of the pan? Does it allow to much room underneath and allow a vortex to form letting it suck air from the top?

Gray86hatch

iTrader: (83)

What does the screen look like. Some of these pickups need help to get the oil in them

Tim

allblowdup

Well put the factory windage tray back on and the ct525 oil pan and no issues now. Thanks for the help guys!

Gray86hatch

iTrader: (83)

Good to hear.

Tim