In the past I have used the oil cooler from a Buell Ulysses on my touring bikes. They really seem to work well. So I am considering mounting one on my 2017 RGS. The only thing I haven't decided is whether to cool the oil going through the engine, there by bringing the oil temperature in the pan down or to hook it up as a secondary cooler for the heads to lower the temperature of that oil before it cools the exhaust valves in the heads. I have been told that the best place to put it would be where the oil is exiting the heads and going into the pan, but I think the plumbing would be a little excessive. So like I said, I'm looking for feedback or opinions, preferably with some reasoning as to why you would go that route.



oil cooler 2

This is what is looked like on my '09. In later adjustments I got it to set in a more vertical position.

 

hey SC, particular problem trying to address or just a proactive feel good thing? why not just use the HD Fan assist cooler? I like the idea of the oil being cooled down (up to 50 degrees they claim) in slow or stopped traffic before it gets to its destination of cooling the heads/exhaust valve area, etc. wife and I have 60000 miles with them using just HD360 around 4K OCIs, and while I don't know what oil temps are I have confidence that it's performing its intended purpose very well..also like the KISS principle and less is more without addt'l clutter, points of potential failure, etc

 

Check out Love Jugs I have the Mighty-Mites on my RGS, I like them.

 

Less is more......i see other things that need a little help.....here in new england 1-2 months if u sit in traffic might help a bit....i just dont do traffic. The rest of the time it would just be extra crap to go wrong . Ie leak.. todays oils can handle the temps in the small amount of mikes most put on before oil changes

 

I had an interesting discussion with a HD tech recently about oil coolers. Due to the Vegas heat (which is similar to your AZ heat), I asked about swapping out the factory cooler on my 2019 SGS for a HD fan assisted cooler, and he said no, that it is better to go with the deeper pan that adds another quart of oil. I haven't thought about it enough to form an opinion, mostly because I don't have experience with either method.

Don't shoot the messenger.

 

Jims ForceFlow Cylinder Head Fan.

 

I do have the fan assisted oil cooler. When Steve was monitoring the oil temperatures on his M8 the oil coming off the rear head was in excess of 300 degrees with 70 degree ambient temperatures. I would like to see less than that.

I have used Jason’s FCS on a couple TwinCams. The TwinCam heads have a tunnel that allows air across the top of the head from a fan. The M8 doesn’t have that so I’m not sure the fans would be ad effective. If I was going to do that I would probably do one fan between the cylinders.

I live in the Phoenix area of Arizona. We experience 100+ temperatures from June into September, sometimes getting to 115-120 F. Since my M8 motor is oil cooled, I surmise that the cooler the oil is going into the heads the better job it will do of cooling them. Even synthetic oil will eventually break down if subjected to high heat long enough. Just trying to make sure that doesn’t happen.

 

From Steve's tests and reports..fan assist cooler made a huge difference..but yeah, you're environment is brutal so can understand wanting to do all you can

The weather has warmed back up to the same as the first round of testing. Now the bike is equipped with full instrumentation and recording of the ECM data along with the Front Cylinder Head temperature, Rear Cylinder Head temperature, Oil Sump temperature and Head Oil Return temperature. I saw slightly less Measured Engine temperature on this ride than I did in the first testing, 351 F the first time and 340 F this time. The ride was in-town running posted speed limits with light to no traffic, for about 18 miles.

Conditions:
Ambient temperature during testing upper 70's
In Town riding with little traffic but normal stop lights
Speed limited to posted speed limits (35 - 45 mph)

Results:
Measured Peak Engine temperature = 340 F
Measured Peak Oil Sump temperature = 267 F
Measured Peak Head Oil Return temperature = 290 F

So for me, its change the oil to full synthetic and wait for the fan assisted oil cooler to come off back order. Once the new oil cooler arrives I will install and test again.
-------------------------------------------------------------------------------------------------------
New test data with HD Fan assist Oil Cooler, same test ride as before.

Conditions:
Ambient temperature during testing low - mid 70's
In Town riding with little traffic but normal stop lights
Speed limited to posted speed limits (35 - 45 mph)

Results:
Measured Peak Engine temperature = 302 F
Measured Peak Oil Sump temperature = 201 F
Measured Peak Head Oil Return temperature = 240 F

 

Oilbud makes a cooler for the M8 now. Much more surface area than stock coolers. Granted I do not live in your area but even with the weather here in Komifornia is 100 and I am in traffic I dont see temps over 235 read from the oil tank on my cvo breakout. Extremely efficiency cooler.


https://www.harleyoilcoolers.com/pro...ouring-bagger/

 

Seems like HD anticipated your exact needs when they offered the extra capacity oil pan https://www.harley-davidson.com/stor...pacity-oil-pan.

They even reference that its for "…. for the rider that tours in extreme temperature conditions …. “.

Personally, more fans or plumbing generally results in more leaks or failed components down the road. Keep it simple by just adding more cooling effect for extreme conditions by circulating more oil. Seems like HD anticipated your exact need.

Note: just realized you have a 2017. I don't believe HD makes an extra capacity oil pan for the M8. Maybe there's an aftermarket extra capacity oil pan??