When we ran Legends Cars, the factory had a dual cooler setup, the engines (Yamaha FJ1200 motorcycle) had a 2 stage pump.

One stage was excluxively for an oil cooler that the bike had.

The factory (600 Racing, factry for the Legends, not Yamaha) was marketing a dual cooler (2 seperate units) when we started that kept the oil seperate (the "cooler" side of the pump returned the oil to the pan).

I didn't notice a significant change in oil temp from having the lower cooler hooked up, to having it bypassed (the one time I tried it, due to damage to the lower cooler, from a mishap in practice ), the factory setup mounted it upside down (Setrab, plate and fin Model# 910-6).

Excellent cooler, others mounted it in different places with (claimed) great success (and the fittings not pointing down).

This leads me to believe a significant portion of the cooler core was filled with air on that one. \:\(

By the time I had that figured out (kind busy with other stuff) I was running a Fluidyne tube style, with the oil coming in on one end (on the top) and out the opposite side bottom to the mains, with an oil line (dash 3) to the cams out the top, opposite of the oil coming from the filter (oil cooler in).

As a tube style cooler it was kinda odd, so here's a pic.



As I swiped tht from the Fluidyne site, here's the link to that page: http://www.fluidyne.com/pl_legends.html

It was the best setup I actually tried, with the line to the cams it was self purging, as the air had somewhere to go, and with the small line to the cams, the mains got the lions share of the oil (as they should).

FWIW the factory came up with progressively larger coolers, including multi pass ones.

The hot setup when we stopped being a dealer was a "920 3 pass", I wanted to try one but we were selling them faster than we could get new ones (people were upgrading) so I never got the chance to try them.

They sure looked impressive. \:\)

Point being, in my admittely limited experience, plate and fin, with the fittings pointed "down" is not the way to fly (air lock city \:\( ).

However they don't seem to care if the fittings are sideways, or pointed up.

My, what a steep learning curve. Erik II#5155