Puzzling Dry Sump Issue

[JeffR 51]

My 405 race car is currently getting a full chassis rewire and data logging kit fitted to it. The company doing the work asked if when they've finished is it OK to start as they were concerned there appears to be no oil in the boot mounted dry sump tank.

I dropped over there today with the dipstick and sure enough-empty. They felt it may have slowly drained into the engine past the pump impeller and since the car hasn't been started for over 5 months, it seems a possibility. There are no external oil leaks.

 

I've fitted a T piece in the supply line immediately before the pump for oil changes so would it be wise to drain the oil out of the engine and refill the tank prior to starting, or will it be safe to turn it over on the starter with ign & fuel cut to pump it back to the tank?

 

So, has anyone else experienced this? Is it dry sumping 'anomaly' from not having run for an extended amount of time?

[camgti 56]

This may be a silly wuestion Jeff. Didnyou take a reading from the dipstick? If its flowed into the engine surely it would be at the bottom somewhat?

 

(U less theres no engine mounted dipstick?)

 

Very strange. Hope its not major!

[JeffR 51]

I should have been a bit clearer re, the dipstick. Engine is fully sealed, so no dipstick. I measured for oil in the dry sump tank.

[JeffR 51]

Thinking further about getting the oil out of the engine I will probably need to undo the return line & crank the engine to drain into a container then refill the tank.

I don't want to introduce air into the supply line (if it isn't already there) as it takes ages to prime.

[petert 586]

Gravity will pull oil into the sump, past the pump. The amount depends on the clearances in the pump. I generally have 1.5-2L in my sump after sitting for a few weeks. I have a drain in the middle of the sump, to ensure a complete oil change is achieved.

[JeffR 51]

That seems to be case that oil has slowly leaked past the pump and into the engine. It's the standard 'Slim Jim' pump as supplied with the Pace system. Uncertain of the clearances though-never measured.

Since there is a total capacity of 12 litres of which some will be in the filter, oil iines & oil cooler, what is the best, safest way to get it back into the tank? Plugs out and crank it over until oil pressure registers on the gauge or as mentioned in Post 4, drain the oil first & refill the tank?

[petert 586]

Remove the belt and cordless drill on the pump?

[petert 586]

Put a ball valve on the tank exit.

[JeffR 51]

Remove the belt and cordless drill on the pump?

Good idea. I've arranged with Chasers to drop over one day next week and do it.

 

Put a ball valve on the tank exit.

Might need to do this if the car is left unused for a while.

 

He said he can write some coded logic to the PDM, a/ give me engine protection if the pump belt was to break by limiting revs,

b/ no oil pressure at start up by killing spark.

Edited May 13, 2016 by JeffR

[Glos_pug 13 1 Cars]

Pretty normally tbh

[JeffR 51]

Pretty normally tbh

Have you fitted a tap to prevent siphoning or is it used often enough to not worry?

[Glos_pug 13 1 Cars]

No tap but we always check the level after a short idle run. We got a rod to check level in the tank 2cm below baffle plate. It does drop back to sump but once its set we kind of leave it.

[Glos_pug 13 1 Cars]

Oh forgot to say our tank is in the engine bay but it never goes empty. Only drops about an inch over a week.