urgent -oil pickup problem at the track

[mini64]

any ideas please:

engine that ran fine for a couple years at the track but then was parked for over a year. Recently properly pre-lubed and started again. oil pressure good. Out on the track the pressure goes away on right hand corners. this was never a problem for this motor / oil pan package before. short of the pickup falling apart or oil pan baffling falling apart, are there any other ideas why this would happen? I've swapped out the oil pump just in case but no changes. pressure will be fine but drop to almost zero in under a second during the corner, then come back up almost as quickly after the corner. if i over fill the motor it will be fine for 3-4 laps till it has blown out all the extra oil into the catch tank then problem happens again. thanks in advance - trying to salvage a race weekend!

[JJDraper]

Sounds too simple, but low oil level fits the symptoms - has your dipstick/tube shifted down?

Jeremy

[rgh0]

Assuming the car has run that track and corner in the same way before OK then it does look like something has changed inside the sump to affect the oil pick. The high oil level temporarily fixing the problem indicates the same.

It could be a bunch of issues - different type of oil, different response of oil gauge ( you may always have had and just did not know) , bearings worn and more oil staying in the head, rings worn more blowby causing more loss of oil into the catch tank, sump baffle broken or come loose or gate stuck if you have swinging gates, blockage or breakage in the pick up somehow.

What sort of pick up and baffle arrangement do you have ?

Maybe the only way short term to salvage the race weekend is to back off and maybe change your line for this corner until you reduce G loads sufficiently for the problem to go away. If the engines bearings start to rattle after the oil pressure loss, back off quick as they will only last a few seconds in that condition until you sieze a big end- been there done that.


cheers
Rohan

[Elan45]

You've not told us anything about your pick-up arrangement or baffles. or whether your engine has a screw in or press-in type pick-up. Do you have a swinging pick-up mod?

I would suggest that your problem has nothing to do w. the storage time, but more to do with cracks forming in your baffles that have finally broken, leaving you unprotected.

As much as it will pain you, I would load it on the trailer. Better to do it now rather than after you've spun a bearing or worse.

Roger

[mini64]

Once again I have to say this is a wonderful website! I pulled the pan to check it out and found nothing wrong. I'm going to say its just past it's prime, blowing out oil from blow by. Compression is considerably down from last time I checked, not that I am consistent with checking. We trailered it for now. Got third in qualifying before parking it though.

[denicholls2]

Another possible explanation: Driver improvement increases G-loads in cornering.

Before you parked it, would you have qualified third?

[bill308]

Still no detail on oil pickup, baffles, gates.

Is it a standard, centralized screw in (rope seal-type), or side mounted, pressed in (lip seal-type) pickup?

Bill

[Elan45]

I have always had a problem w/ oil slosh in RH corners in my S3-SS. Back in the 80s, I made a windage tray for it but that didn't do much to help. When I had the pan off in 2011, I did some measuring and determined that the press in pick-up pipe was at least a 1/4 off the floor of the pan. I never had any faith in that style of pick-up and it being that far off the floor, it was pretty useless.

So, in 2011, I modified that pick-up by spring loading against the bottom a funnel shaped one from an earlier screw-in pick-up. I brazed the funnel to a steel sleeve that slides on the press in tube. But now I have the car in Florida and it seems that Lotus type twisty roads are few and far between for a good test. But a stock press in pick-up system is pretty poor.

Roger

[mini64]

sorry if I wasn't clear at the beginning. I've raced this car for over 20 years now with more or less the same pan pickup/baffle/gate design. So I was looking for an explanation apart from the baffles failing. I think those that responded hit it on the nose - tired motor in one way of another causing increased internal pressures to blow out too much oil.

to answer the curious - I use a custom pickup that mimics the old funnel type located in the center, pan baffles and gates on either side of this with a windage tray on top that slopes down in as many directions as possible towards the pickup hole, cranks scraper and a pan extension to the left for a bit more capacity. A bit of crude fabrication work but it has worked well. Below are a couple photos from a different motor of mine: