Dry Sump Plumbing Options

[JeffR 51]

Where is the best location is in the oil supply plumbing for an oil cooler?

1. In the scavenge return hose to the tank?
2. In the pressurised output from the pump before the oil filter then into engine?
3. In the pressurised output from the pump after the filter then into engine? (this is the way I've connected mine).

Reason I ask is that I've noticed with my set up (#3) the oil pressure drops from 55-60 psi at high(ish) revs by about 10psi as the engine speed increases, then rises again as speed decreases.

 

I suspect that the cooler is allowing partially aerated oil into the engine and the degree of aeration increases with engine speed and lowering the pressure.

[petert 553]

In the scavenge return line between pump and tank.

[Sandy 189]

Unless you're doing endurance, cooler probably isn't needed if you're running 5-7 litres in the tank. Try without and see what the temp does.

[petert 553]

Sandy has a point. I tape mine right up in winter but it runs 90+ in summer. It really needs to run at 100-105.

Edited November 23, 2015 by petert

[JeffR 51]

If I fit it in the scavenge & the tank, I'll need a new cooler in AN12 size (-10 now) or could I still use it with reduced fittings?

 

Tank has 12 litres of oil & temps still get to 110-115° doing 6-7 timed sprint laps. Wouldn't running without the cooler send that higher?

Edited November 23, 2015 by JeffR

[petert 553]

Best to still run the cooler then. I used a -10 cooler with reducers, in the -12 line. It works fine.

[Rippthrough 98]

You get better cooling in the line to the engine from the tank, but also extra pressure drop, which can be an issue - but you shouldn't be getting much aeration in there unless your tank design isn't working very well.
I'm running on the scavenge lines on the buggy because the oil cooler is oversized anyway and I can't afford the pressure drop the cooler + pipework would bring into the feed line.

[JeffR 51]

Fitting the cooler in the scavenge return to the tank seems the way to go. If getting the oil up to proper operating temp becomes an issue, I can blank some or all of it depending on weather conditions.
Hopefully I can get it done before Phillip Isl on 13th Dec.

Thanks everyone for their input.