dry sump tank filling up sump overnight? 1

[roadracer55]

I'm still building my car, with a chevy v8 and moroso dry sump system. Since Moroso recommend that the tank is fitted "slightly higher" than the pump inlet I wondered if the oil from the tank could leak through the pump into the sump.

Obviously if enough oil gets into the sump from the much larger tank you could "hydraulic" the engine when starting it, right?

Moroso confirmed that indeed oil can leak back overnight, and this is why they recommend that the pump is primed before starting the engine each time!

On a road car this isn't practical, but there are many road cars with dry sump - porsche/corvette/etc - so do they have a solenoid-operated shutoff valve perhaps connected to the ignition circuit? or some other solution?

Or of course, is this theory and not practise - and very little oil leaks down through the pump..

Any comments/suggestions much appreciated!

 

[evelrod]

From a practical point of view...on my drysumped cars of the past, I had a simple ball valve that I could close when needed. I also had a "Remove Before Flight" banner pinned to it because so often I find my head up my arse where I cannot see all that well! My current two race cars are wet sumps so the problem is moot.

For a street dry sump, all I have is my 1948 Norton and it too has a shut off valve (with the same red flag precaution) as it will drain back 'overnight'. The drain back problem was never too much bother on the bike, but once on a Pantara with a 24 qt. tank...I never took the chance and installed the ball valve from the 'get-go'!

Rod

 

[roadracer55]

thanks. yeah, i'm going to put a shut-off valve in, and run a cable to the dash. Just so I don't forget I've wired in a switch that cuts power to the ignition if the valve is shut!

 

[mrbike]

Harley V Twin oil pressure problem with tank - I have just built a new Evo 1340 motor but it's hell bent on blowing the oil tank dipstick sky high. W-H-Y????I've read here that could be too much oil in tank - well I have left 2" from top of tank for expansion and the bikes only been running on the bench so it not oil overflowing into the return or breather tubes in tank. The tank is an aftermarket round type fitted to a Softail. Have just dissasembled the nose cone to check timing gears and breather and all are OK. Have also fitted 1 way breather to bottom engine crancase hole to stop oil sucking back into sump, 2 ng higher up breathe vents to tank.
Stupid question - wht are the tank cap/dipsticks not vented to release pressure in tank?

 

[JDana]

mrbike,

I believe you wanted to start a new thread, not add to this one.

You do so by "going back a screen" to where you see the list of threads in your topic of choice, then scrolling to the bottom where you can "start a new thread".

It looks suprisingly like where you did post, but that was actually a reply to this thread.

I hope this makes sense

 

[swall]

My '52 Indian has a spring loaded ball check valve on the oil pump outlet to prevent the sump from filling when the engine is not running. The oil tank is mounted high and you have gravity feed to the oil pump, so no loss of prime. It is a simple and "idiot proof" design.