Oil coolers...

I have seen some of these mounted on Nortons and other air cooled bikes that look like they are doing more harm than good in that they are blocking airflow to the head and cylinders. That is where the majority of heat from combustion is being dissipated through the valves and rings. Look where the majority of the fins are on the engine. Very little of the "cooled oil" is going to that area. I've also seen tool bags mounted to the forks that do a pretty effective job of blocking air flow to the head.

I have an Lockhart Oil Cooler that was made for the Norton 750/850 around 35-40 years ago. In order to prevent the oil from staying too cool, I installed an inline thermostat from JAGG. It is a unit that is smaller than a pack of cigarettes that begins to open around 185 degrees(f) and is fully open at 195 degrees. Based upon my research with some oil engineers (I guess that is what you call them) with the type of oil I use, it is about the optimal oil temperature for my application.

I would NOT use an oil cooler without the benefit of a thermostat, or at least an oil temperature gauge and manual by-pass valve to compensate for cooler temperatures.

http://www.jagg.com/by-pass.htm

I have been running my Lochart oil cooler on my Norton for 36 years now and have had no problems with it, I mounted mine just under the steering head where the frame joins and is above the front gaurd so it gets clean cool air all the time, I run my oil lines along the under side of the frame and are well hidden.

When I brought my Norton new and for the first year ran without a oil cooler, during summer when stopping at lights the Norton would idial to high because it was running hot, but after putting the cooler on I never had any more problems with it getting to hot, it also runs so much better at high speeds when oil is cooler, remember these motors were made for cooler weather over in England so running a oil cooler in hot climate countries would make sense to me, I run my cooler all year round even in winter.

I do my oil changes at 2,500 miles and have never had any problems with moisture in the oil, if I throught that my motoer was running too cool in winter all you would have to do is put a cover over the cooler, but I have never done this as I haven't had any problems with the running of my motor.

So I beleive the oil coolers make a big diffrents to running I have run a oil cooler on all my British bikes and when my 650 Manxman is back on the road it will have a cooler mounted as well.

Ashley

Thanks to Steveyacht for pointing out a clean thermostat control solution.

When I was looking for one of these either it was not around or I did not look hard enough when I was looking. I will be picking one up for the Nourish Weslake build.

I ran a Lockhart on my 850 Mk2a back in the 70's but only because I ran a Drouin blower with 10 psi boost. It was a tidy little package and if I recall correctly it sat right up under/behind the steering head.