Subject: [FlyRotary] Re: oi/water Exchanger [FlyRotary] Re: fluidyne oil cooler

 

I was considering the idea when I was planning my installation and one big question kept popping into my mind: which side of the rad do you put the interchanger?

 

-From the standpoint of the coolant temp at the radiator, it makes essentially no difference.  The total heat rejection requirement remains the same, and it will take the same coolant/air delta T either way.  What I’ve seen, they are generally plumbed in on the return side of the rad to get better heat rejection from the oil, and the piston guys like to have the engine run a bit hotter for better efficiency. This may not be true for a rotary.

 

I’d guess the best place to plumb it depends on the balance of your system.  The oil/water delta T is generally going to be 20-30F, and the oil can run that much hotter than the coolant, so no matter.  To put a fine point on it, you could see which way you get more power from the rotary – a little higher oil temp (interchanger on the coolant out side), or a little higher coolant temp (interchanger on the coolant return side).  Which ever way gives you more power out (if any) will result in a couple of degrees lower rad temp.

 

Al