Oil coolers only work as designed while you are moving, getting stopped in stop and go traffic they will have a very minimal impact, if any on the temps. That being said, if HD really believed the stockers needed them for survival, they would have installed them. Millions of bikes out there running around without them.

Yes, if you build the engine, then it is definitely a consideration, or if you just want the peace of mind. You mentioned the gauge, that is air temp and doesn;t have a thing to do with engine heat. If installing an oil tempgauge, mount the sending unit in the oil pan, truer readings. HD recommends mounting in the line to the cooler, this does not get any hot oil unless the emgine temp gets above 185 degrees, so it will stay on the bottom until the oil thermostat opens, then the gauge will climb like crazy. Mount the sending unit in the "spare" hole that has a plug in it in the front of the pan using a 3/8" by 1/8" bushing.

 

Amen to that.

 

Other than over-revving the biggest cause of Harley engine failure is lack of proper lubrication. Harleys may be called air cooled, but the oil helps with cooling. The Evos could get away with out an oil cooler better than a twin cam because the twin cam has the jets that hit the bottom of the piston and draws a lot of heat. There are a lot of engine builder out there that have either not taken this into consideration or choose to ignore it. This heat goes right into the oil. All things being the same between an Evo and a Twin Cam the twin cam will have a higher oil Temperature. The higher oil temperature will denegrate the oils ability to lubricate and this will give you a greater chance of engine failure. All the twin cams that we build get Jagg oil coolers. A lot of the high performance automobiles came through with oil coolers and they are water cooled not air cooled, what does that tell youThe customers that do not want one get a lecture about the dangers of not having one. In closing this is our opinion and ours alone there are people that do and donot agrre with it and that is their right.

 

I heard that the MoCo engineers recommended an oil cooler but Willie G nixed it because it looked ugly.

I put one on - IMO best $$$ I spent (only in high temps does it get above like 180-190 degrees). I even have the MoCo fan kit - now that is a bit on the ugly side - would not recommend the fan.

 

This topic comes up every few weeks. I still haven't seen any convincing evidence that adding an oil cooler improves either the performance or longevity of an engine. I suppose if you lived somewhere like the desert southwest it might be something to consider.

What I don't ever see addressed is the additional risk you take by running oil lines and connections to a poorly protected device sitting exposed and vulnerable towards the front of your bike. Seems to me you have to figure in that downside to whatever plus you feel the oil cooler will provide. Damage any of those parts and you will have real problems!

A good synthetic oil and SERT is probably much more advantageous.

I understand an oil cooler will drop the temperature several degrees. I just haven't seen the evidence that really impacts on the longevity of the engine IMHO.

 

I agree the cooler is unecessary.Tune it right and it will last a long time