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Oil cooler control

Oil cooler control

Oil cooler control

I'm trying to come up with a slick (and cheap) way to control oil flow thru/around a cooler on an air-cooled motorcycle.

When the oil temperature reaches, say 190F, I want to gradually switch the flow thru the cooler.

I found a self-contained temperature valve that will close/open with temperature. I could use one in the line from the oil pump to the filter and slowly close it to force oil thru the cooler when it's hot. To keep the cooler out of the loop when cold, I would have to use another (reverse-acting) valve in the cooler line. The problem is that these valves are $132 each. By the time I added the extra plumbing, parts cost would be near $300 ($150 if I used only one valve).

I could also add a temperature switch with a 3-way solenoid valve, but it would not be much cheaper. Besides, I don't like suddenly switching oil flow at 3-8000 RPM.

Does anyone know of a 3-way, self-contained, thermal valve? Know a way to plumb up a carburetor choke control? Anything else that might work?

The oil line is 3/8" (1/4" NPT fittings). Pressure is under 50 PSIG and temperature could reach 250-300F. Heavy vibration and exposed to the elements.

Appreciate any suggestions.

        . . . Steve

RE: Oil cooler control

Why not use a blind over the cooler?

Or a radiator thermostat (by the way your oil sounds too cool, I'd expect to see >212)

Or a memory metal valve?


Greg Locock

RE: Oil cooler control

Normal (high) temperature in the oil tank is about 200F. Since the oil is coming from the pump, you're right, it will probably be at a higher temperature.

A radiator thermostat is too large, unless you know of a small one.

What's a "memory metal valve"?

Thanks for the response,

       . . . Steve

RE: Oil cooler control

You can buy oil thermostats.

I used them 20 years ago on air cooled VW's.

They were made by the same company that made the oil coolers used by BMC on MGB's and Mini Coopers. As it was about 20 to 30 years ago, I have forgotten the name, but I am sure you could find it by Google


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RE: Oil cooler control

Look at this site. I have used their products in an industrial application with out fail. They do have temperature/pressure activated valves but not in the size or temp. range you have stated. Of course my catalog is outdated. You'll see their into racing too! and thats a good thing for you.


Good luck


RE: Oil cooler control


Follow this link for some info. I have dealt with this compmny with good results, some of their stuff is fitted to my 850cc trials car. They manufacture and distribute MOCAL products and are very well respected in UK.


Hope it helps.


RE: Oil cooler control

I purchased the Mocal sandwich-type adapter with the built-in thermostat for the Harley. It looks like it will work out just fine. I'll let you know.

RE: Oil cooler control

IRS / Serck Marston in the UK do a Thermostatic valve for O/C applications, I think you may be able to by thru' Industrial Radiator in Denver for the USA. These valves are cheap, small and work just fine.

RE: Oil cooler control

Serek was the one I used on the VWs. I put it after the full flow filter I adapted, and before the cooler, so it sometimes bypassed the cooler, but never the filter

pat   pprimmer@acay.com.au
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