All you engineers out there are gonna love this! Earlier this week I installed some oil cooler fans and a LeNale engine cooling fan to my 2011 Limited. You can see the install at https://www.hdforums.com/forum/touring-models/603524-engine-cooling.html

Today I did some testing to quantify how well the fans perform. These results are for the LeNale engine fan. I had a little trouble with my oil temp monitoring set-up so I need to repeat that part of the testing another time.

Here’s the test methodology used for the engine fan:
(Ambient temperature was 70 – 72 degrees F during testing)

1)Ride bike to get to operating temperature.
2)Connect the bike (Power Commander) to computer to read
engine temp through PCV software. The PCV displays the ECM
reading of the cylinder head temperature.
3)Run the bike at idle (1,000 rpm) with fan on to establish baseline
temp.
4)Record engine temp.
5) Turn fan off and continue to run at idle until the Engine Idle
Temperature Management System (EITMS) activates. The
system activates at approximately 290 degrees F.
6)Record engine temp and time.
7)Turn on fan.
8) Monitor and record engine temperature vs. time.
9) Turn off fan when engine temp stabilizes at lowest value attainable.
10) Repeat steps 3 - 9.

And here’s the test data:

With fan ON - 244.4 deg F baseline. Time (T) = 0 minutes

Turn fan OFF @ T+0
293.0 @ T+2 (EITMS activated)
Turn fan ON @ T+2
296.6 @ T+2’15”
276.8 @ T+3
262.4 @ T+4
255.2 @ T+5
249.8 @ T+6
246.2 @ T+7
244.4 @ T+7’30”
244.4 @ T+9 (temp stabilized)
Turn fan OFF @ T+9
266.0 @ T+10
293.0 @ T+11 (EITMS activated)
Turn fan ON @ T+11
298.4 @ T+11’15”
280.0 @ T+12
266.0 @ T+13
258.8 @ T+14
251.6 @ T+15
248.0 @ T+16
246.2 @ T+17
246.2 @ T+19 (temp stabilized)
End of Test

Summary:

I am very encouraged with the results and believe the addition of the fan was most definitely a worthwhile modification. Engine temps with fan running were 50+ degrees cooler than without. The engine temp would clearly exceed 300 deg F at idle with the fan OFF if I let it run to that point. With the fan ON the engine temp never exceeded 246.2 deg F.

One of the really cool things was to hear the EITMS disengage within a minute or two of kicking on the fan. That alone makes this mod worth it to me.

We’ll see how this works out when the ambient temps go up this summer, but regardless of the actual temps, it sure feels good to know that they’re 50+ degrees lower than they would have been without installing the fan.

EDIT: 1-27-2011 9:27 pm. I'm adding this to address a couple of responses I've gotten relative to running the bike down the road at speed. The purpose of this test was to simulate the effects of being stuck in traffic. Stop and go. Nothing more, nothing less. The relevance of this test, or the fans themselves, is nil if you try to apply it to a bike travelling down the highway at speed. My fault for not clearly stating the purpose in the original post.

EDIT: 2-23-2011, Re-ran the oil cooler fan test and here's the results... https://www.hdforums.com/forum/touri...test-data.html

 

Nice job!! Data is data, and your test shows the results clearly. Great write up!!

 

Great post, this past fall I had the 103 kit installed and may have to do something like this for the summer heat. Thks...........

 

Superb data! Any issues with hot knee when the fan is on?

 

Don't really know as I haven't used it in actual conditions yet but I don't think it's going to be too bad. Without the fan the heat from the engine, and it's a bit higher temp, radiates to your legs anyway. With the fan blowing there is more airflow towards your leg but it's diffused a bit by the intake system and the air cleaner... It's not a straight blast at your leg.

Even it's a little warm on my leg, I think it's a worthy compromise for the cooler running engine.

 

Good objective data and the evidence thereof--good job well done!

 

Great job and write-up. Is this with just the LeNale fan or are you using the oil cooler fans too?

 

Nice work! I’ve done my own fan project, so I know what you’ve got going on there. Don’t take this the wrong way, but knowing what I know about Twin Cam cooling, your results at idle at 70F ambient do not particularly impress me. Not to discourage you in any way but I’ve done this type of testing extensively, and you are going to see radically different results at 95F ambient, turning 3k RPMs. Keep your testing in alignment with real operating conditions if you want reasonably accurate results. Keep driving on with the project, its looking good.

 

I know the results will be different at higher ambient temps but these results are what they are for the parameters and limitations of the test I conducted. And although the results definitely point in the right direction, I understand that they are not all-encompassing.

As far as going down the road at 3,000 rpm's, the fan will not even be active at that point. My primary objective was to minimize the temperature rise while idling in traffic and that is where the fan will be active.

Let me assure you, there is no offense taken at your comments. Quite the contrary... I appreciate your critique. Nobody (even me, LOL) knows everything!!!

 

i can see how this fan theory would work, but you left something out of the equation. the test on your bike was done without the bike moving through the air. our motors were designed, obviously as air cooled motors, and any air cooled engine if it's sitting in still air will overheat. and yes, i was a mechanical engineer prior to retiring 9 years ago. get your bike out in the wind, that's what it was designed for.