Ok, thanks everyone, it sounds like the oil temps on my bike are nothing to worry about. I just didn't know how far apart the ET and OT were gonna be. Sounds like OT is about 30 or so lower than the ET.

 

I wish my bike ran that cool.

 

Very interesting.......I guess I'll put my fairing lowers back on during the hot summer months.

 

with worrying about engine temp and oil temp readings. I believe this is far too much info for the average rider and the quest for a bike that runs cold will always be elusive. I'm not concerned with 260 degree oil temp and god knows what the head temp is at any given moment. HD has been making air cooled engines for over a century and that was with crude and unsophisticated oils and they ran quite well. I can't believe how obsessed we have become with all these gadgets that give us info we really don't need (or understand) I've had liquid cooled bikes that ran just as hot as my RK in the summer.

 

Just reading that MoCo is bringing out a water cooled RG Ultra for 2012. Wonder what ET and OT on this will be.

 

I just read back through this thread and I didn't get out of it what you did. Sounds like you have interpreted exactly what you wanted to hear. I've been closely monitoring my temperatures for a couple years while developing cooling systems and I can assure you that there is no way to convert ET to OT, just too many variables.

 

oil will be lower. your eng temp is coming from a sensor located on the heads which is the hottest part of the bike.

 

I pay no attention to any of it. I buy good synthetic oil and forget about it. My engine hasn't melted yet. If you have an oil cooler...you should be good to go anywhere.

 

Watch Guy, you are 100% right!

 

ET (Engine Temp. measured on the front head) and OT (oil temp., usually measured in the pan) are very different readings, and Fabrik8r did a good job of describing the relationship. I've monitored both for over a year on my '07 and have seen as much as 100° difference between the two, and like Fabrik8r said there is no way you can infer one from the other, except that on my bike at least ET will always be higher than OT. Well, I suppose maybe if you were in a strong wind and let the bike sit for 20 min. the head might cool fast enough to settle below OT at some point in time, but that would be a rare event. ET fluctuates much more rapidly, and IMO is the best measure for real-time engine temp. OT is a slower movement and will generally stay lower than ET, usually considerably so.

What engine configuration do you have? The 103's I've seen run hotter than 96's, more than would seem warranted by a displacement and compression increase alone. My 96" with 255 cams and lowers runs 225-235° ET on the highway in this 95-100° weather, but at 60° it will barely tip 200°. This bike runs cooler than most for some reason, and oil temps stay sane too, rarely >205° with 230° being the highest I've seen in 4½ years (gridlock traffic in summer). What makes it even more odd is that I run stoich in the cruise range (14.6:1) and around 14.0 at idle, which by conventional thinking should make the bike run hot as hell. This summer has been the hottest on record here and ET hasn't exceeded 290° yet, OT at 220° a few times, but that high only in heavy traffic. If I had EITMS working, which I don't, it would kick in at 290° ET, so it would be a rare event. EITMS is available for the '07 but only on one firmware version, which I had at one time but currently don't. Other models will activate at different ET's, but I understand it is generally 285-290°.

I believe a critical component to engine cooling is an oil cooler, and I have an HD cooler installed here. I wouldn't want to ride without one, but I've seen a few 103's that run hot like yours even with a cooler.

HD claims that lowers can actually help cooling when the bike is moving, but they can trap air when stationary. MKguitar has made the same observations, but others claim they make their bikes run hotter. I find that they help with cooling on my bike, though not as much as MKguitar has observed, as I've had them installed for 3½ years and have found temps to be a tad cooler (maybe 5°) while moving. When stopped I have seen no changes. I think with their wedge shape they scoop more air and drive it into the engine, and they might even improve flow at the cooler.

Depends on the year-model. My '07 would activate at exactly 290° ET, but based on reports here later models can be different. I don't know if it varies from bike to bike within year-models, but I doubt it.