A brother wants to put an oil cooler on a 1974 XLH and do it as economically as possible.  Can he use a car's transmission fluid cooler?

Not sure why you would want to really? By the time you have sited it presumably under the front somewhere and then added some kind of grit guard over it and damaged the frame to fit all of it would it actually be of benefit? I dont think so...

yeah and if you mount it on the front of the cradle frame blocking the motor from more of it's natuaral engine coolant (air) then it will probably be about the same as far as just not messing with and oil cooler at all. Why does he want an oil cooler on an iron head motor anyway? Ambient temps never burn up motors only ding dong bike riders who don't understand where the RMP range should be in certain gears at higher speeds.

He used to ride Triumph's back in the day, and his had an oil cooler, so I'm sure that's part of it.  I think he checked out a cooler from J&P (which doesn't block air flow)  and I told him I'd see if anyone had re-purposed a transmission fluid cooler. As for the advisablity of it, that's not in my area of expertise.

I would have to ask the same question, why would he want/need the cooler.  The HD air cooled engine has been around and running just just great with nothing but air cooling for years and then someone came up with this idea of selling oil coolers.  I ride probably A LOT over 100° temps, and many times over 110° and never had a problem caused by engine heat.

You may also want to read some of the topic hear on V-Twin engine temps and some of the input... http://www.cyclefish.com/forum/topic/11/index/3634/1 />
However if he wants to do it, it won't hurt anything.  I don't see any reason an old trans fluid cooler wouldn't work.  As long as it has tubing for oil to run through and air blowing across it, it will cool the oil down some.

Yep, I ride in over 100 degree temps ALL the time and still don't run an oil cooler. I have many friends that do and really don't see where it helps all that much. As long as I'm moving the air cooled engine stays cool (enough), and when stopped the cooler doesn't help because there is no air blowing across the fins and coils anyway!

I could see it having some effect if you also added a spraybar to the cooler system and had water injection system added to carbs, of course, to do this you would have to include spray injectors and a charge cooling system as well to cool the water going in the carbs...lol...so why not add a supercharger as well...lol...but then...do you really want to have water tanks as well?


I have seen a Harley with a volvo supercharger and full charge cooler system ...no idea what kind of gain it would have been apart from proving it is possible to do...the weight gain and wind drag would negate any horsepower gained...lol...Also he had to rake the frame for clearance to install a radiator in front of the engine...lol...

AZ yup lived in Phoenix for a year and a half and my first day there it was 112 degrees... YEEOWCH! heheh