That video is simply mislabeled. That's the twin-cooled system complete with water pump and no oil cooler.

 

Yup, not what we're talking about.

 

Sorry, but you are wrong. If you look at the models you will find they are separated by Water Cooled and Air cooled by the models themselves, I just made it easier for people. Your 80 degree is the 27 degree C we are talking about. For the record the water cooled bikes have an ambient air temperature sensor, the air cooled bikes do not, so that input to the ECM is not used. This would not be the first time HD had a mistake in there documents just look at the video posted above as a perfect example! That video is of a water cooled bike NOT an Oil Cooled version, yet it clearly states Oil Cooled.

My concern is from real measured temperatures in the M8 Stage I equipped bike running in 75 - 78 degree ambient air temps. With engine temperature running in the 330 + range (as already documented) the oil is going to be close to that number. If I had to guess (which is all I can do for now) I would bet that it's within 25 - 30 degrees of engine temperature. If correct, that would mean oil temperature of 300 + degrees F which is no good for normal oil as it will break the oil down in short order. Also if the oil is that hot in the oil pan the oil leaving the head from cooling it is going to be much hotter. Look up the specifications on any engine oil and your going to find those temperatures are not good for the oil and should be only run for short times. A full synthetic would be a much better choice and if the temperature readings come true the only oil I would recommend anyone use in a M8 engine, after break in.

Now remember the test conditions were riding in town at 35 - 45 MPH on level ground with NO traffic in 75 - 78 degree ambient air temps. and 60 - 75 mph freeway speeds in the same conditions. Both test are going to be rerun once the engine if fully instrumented with oil temp in pan, oil temp at the head cooling exit and cylinder head temperature on both the front and rear heads.

This information is necessary so we know what is going on for sure. One needs to understand that 75 - 78 degrees is nothing for So. CA temperatures and traffic is another big deal out here. To sit stuck in traffic for a 1/2 hour in 90 + degree temps is very common. Now think about what's going to happen once you start increasing the power output of the engine above a simple Stage I or running in higher ambient air temperatures.

 

Wow, ok.

Steve, all fairing bikes with radios have an AAT because it is the sensor used to display ambient temp on the radio.
If the bike has an AAT, EITMS uses it...
If a bike does not have a radio (non fairing bikes and the FLHTP police bike without radio) EITMS uses the ET sensor instead.

It has nothing to do with water verses air cooled. The service bulletin is correct as it separates models by fairing and no fairing. Or more specifically, radio/no radio.

The rest of the stuff you said is pretty interesting but I don't think the sky is falling. Can't wait to see some data one day.

 

Steve,
As the owner of a 2014 FLHTK (Twin Cooled 103) I have to disagree with your statement concerning ambient air temperature sensors. All of the Rushmore bikes with a fairing and the Infotainment radios should have an ambient air temp sensor located on the left side of the frame neck. This sensor is used to display Air Temp on the Vehicle Information Screen and to activate the EITMS at temps over 80 degrees. I know this sensor has nothing to do with engine temps and is strictly ambient air temp. Just by removing the sensor from it's retainer on the frame neck and placing the sensor on top of a hot rocker box, you can 'fool' the bike's EITMS into thinking that the ambient air temp is above 80 degrees. This will cause the EITMS to become Active providing of course that the other criteria (idle, speed, run time) have also been met.


LP you obviously type faster than me.

 

You really are clueless for someone who thinks he knows everything. ALL fairing equipped Rushmore models have an ambient air temperature sensor & it is used for EITMS.

 

What you say is correct but maybe not clear.

1. Technically there are 2 pumps in the system.. A feed and scavenge pump.

2. The feed pump, feeds both the motor and the oil cooling system.

3. Motor side oil goes through the oil filter before the motor.

4. oil in the motor is picked up by the scavenge pump and returned to the oil pan.

5. Oil the flows through the oil cooler and heads then back to then oil pan and is not filter..(don't need to be)

6. All oil fed into the motor filtered. (pretty much the same as #3)

You can say that eventually all oil will be filtered as the oil that passes through the pump can either go to the cooling system or the filter but that really isn't as important as saying all oil going into the motor is filtered..

 

Well this is interesting as all get out. Can't wait to see what more questions (or answers) the engine oil temp data brings!

 

Yeah I thought my initial question was a simple one to answer. I was wrong.

 

Well the ambient weather conditions have cooled since the last testing. It was about 10 -15 degrees ambient cooler than before and windy. Previous testing was in the mid to upper 70's and today the testing was in the low to mid 60's. Engine temperatures over the same test coarse ran about 35 degrees cooler today. That said the oil temperatures were tested and recorded and the results were what I was afraid of. Sump temperature ran around 250 - 260 on the high side and around 230 at freeway speeds. The oil return from the heads was where i was concerned and it was 265+! The weather is suppose to warm up first part of the week so I will repeat the testing again when we are back into the mid to upper 70's and see where it goes, but I would imagine with the engine going back up 35 or so degrees that the oil will follow closely behind. Oil is just not going to live long at these temperatures, so it will be synthetic oil from now on in the M8 engines for us, once the testing is completed.