I have read several articles in different bagger magazines that promote the use of quality, correctly sized (for appropriate flow), oil coolers with thermastats. Here is one article that says the opposite. So right now I have seen 4 articles for, and heard of one article against.

Don't get me wrong, I don't think your bike can't live without it. Mine came with one (stock 103), if it didn't I probably would have put one on anyway.

Everybody is free to do what they want I guess, but I have never seen the advice on any engine, bike, auto, or marine that says "Hotter is Better", so I'll be keeping mine cool.

 

Do a simple google search for "Harley Davidson optimum oil temperature". Here's just one of many. None are pro or con re: oil coolers, but rather they deal with "what is the best temp".




Harley-Davidson Manufacturer Motorcycle Oil Specifications

Ten Questions and Answers About Motorcycle Oil For Your Harley-Davidson



The Following Information was provide by
Harley- Davidson Service, 3rd Floor.


1. Why should I use Harley-Davidson Motorcycle oil?

This is the only available motorcycle oil specially developed for Harley-Davidson motorcycle engines. It is also the only available oil tested for two years by our engineering staff on engine dynamometer stands in Milwaukee and motorcycle track tests at Talladega. And in other tests, Harley-Davidson has found it to be superior to other oils.

2. Can I use aviation oils in my Harley-Davidson?

We do not recommend this, because these oils do not contain an important additive that provides good wear protection of the Harley-Davidson engine.

3. What viscosity grade should I use in my Harley-Davidson?

The recommended viscosity grade for use in all temperatures is SAE 20W50 Harley-Davidson Oil. The SAE 50 grade is satisfactory in ambient temperatures of 60 deg to 90 deg F, and the SAE 60 grade is appropriate for ambient temperatures above 80 deg to over 100 deg F.




4. At what temperature will Harley-Davidson Motorcycle Oil
break down?

This oil has been designed for use at temperatures up to 300 deg F for extended periods with no significant breakdown.

5. What oil temperature is best for my Harley-Davidson?

A good oil operating temperature range is 200 deg to 240 deg F. Water condensation and acids tend to build up in the oil if the temperature is consistently below 180 deg F, and oil thickness can become marginal at temperatures above 300 deg F.



6. Does Harley-Davidson Motorcycle Oil do anything besides
lubricate engine parts?

Yes. Besides lubricating engine parts and preventing wear, it protects the engine from rust and corrosion, keeps the inside of the engine clean, cools engine parts and "seals in" combustion pressures, prevents foaming, permits easy starting and quick oil circulation, and reduces friction and power loss.

7. Is it true that oil never wears out?

No. All motor oils wear out. During normal use, the oil molecules undergo a chemical reaction with oxygen and begin to break down; additives in the oil become depleted; and contaminants like water, gasoline, soot and dust get mixed in with the oil. Therefore, your motorcycle oil needs to be changed at the interval recommended by Harley-Davidson.

8. Can I go longer between oil changes if I put in a new oil
filter?

No. The filter keeps the oil free of solid matter, but it doesn't remove water, gasoline or acids. Also, it can't pinch-hit for additives that become used up. Follow Harley-Davidson's recommended intervals for oil and oil filter changes, and don't expect a new filter to extend the life of the oil.

9. Is it okay to mix Harley-Davidson Motorcycle Oil with a
different brand?

Harley-Davidson Motorcycle oil is compatible with other petroleum oils. However, mixing with another oil will reduce the superior engine protection of Harley-Davidson oil, so this should be done only when absolutely necessary.

10. Does it help to put in a can of additive with each oil
change?

No. Just as you wouldn't add sugar to a bottle of soda, you shouldn't use additives with Harley-Davidson Motorcycle oil. It already contains the right additives in the correct amounts to last between recommended oil changes. More additives won't help. In Fact, they might upset the oil chemistry and create problems you wouldn't ordinarily have. Use Harley-Davidson Motorcycle Oil and forget the extra can of additive. It's money down the drain.

 

I aint going to say anything but this......Read the notes/fine print in the instalation instructions for the oil temp gauge kit.

From the HD web site.

"NOTE: When installed in combination with an oil cooler, gauge will not read accurate temperature until the vehicle has reached operating temperature and the thermostat has opened."

The MOCO does not put oil coolers on all their CVO bikes. I have a 03' that didnt come with a oil cooler.

If you use a good synthetic you will not NEED a oil cooler. The modern synthetics are still working just fine and have no appreciable break down at even 300*F....and if your bike is seeing oil temps that high something is seriously wrong anyway. Here in NYC in mid Summer we see day time temps in the high 90*F range with very high humidity....and PLENTY of stop & go traffic. I have the HD 2" oil temp gauge installed on my FLHX in place of the useless ambient air temp gauge, and even in dead stopped traffic inside the Lincoln Tunnel the oil temp in the sump/engine never got above 255*F, and I have double and triple checked the temp gauges accuracy with two other thermometers and it is spot on.

Here is my opinion for what its worth......If you insist on using a oil cooler, just make sure you get a high quality unit, and you will not have any "issues" with the oil not getting hot enough to burn off the condensate or reaching its intended viscosity. Using a cooler is a good idea if your planning on staying with petroleum based oils. If your a fan of high quality full synthetics....a oil cooler is not needed in 90% of the country. If your in the South West (I wish I was) and your regularly seeing ambient temps in excess of 100*F then I would get one....even with synthetic in the engine.

 

There is a big difference between an 03 and an 07 IMO. Is your 03 fuel injected? Leaned out to pass EPA?

 

Yes....and yes, but still no stock oil cooler. I have added a HD Screamin Eagle Stage 1 intake, a set of V&H Big Radius pipes, and a SERT. The bike never ran real hot, but it didnt cool off any after the install and dyno tune......it just flat out hauls *** now.

 

I overheated my bike half way through a 3000 mile trip last year when we got stuck in heavy traffic near LA. Oil temp gauge (Macewn) pegged out past 300. The rear cylinder base O-ring started leaking from that. That was all I needed to convince me. After the O-rings were replaced on both jugs under warranty, I installed the cooler.

 

Still no matter what, these oil coolers MUST HAVE air flowing across the heat exchange/core to dissipate heat from the oil. So if your sitting still or moving very slow.....the cooler is doing next to nothing.

I live in the NYC Metro area, and the traffic around here has to be seen to be believed. What 90% of the people in the country would call heavy bumper to bumper traffic we call a normal delay.....and twice a day...at the Am rush then at the PM rush it will just get totally out of hand, and I will not travel at those times if I dont have to. Just riding a bike around Manhattan is a piece of cake....its on the highways and bridge/tunnel choke points and toll booths. I been riding full size motorcycles since 1980....so I think I know a bit about traffic and the air cooled engine.

I would never tell someone who will regularly see "Heavy Traffic" with their bikes not to buy a oil cooler, but there are other options. you have to figure out what you want to cool off. If your looking to keep the engine temps down....yes a oil cooler will help, but you could also buy the HD cooling fan and/or activate (I forgot the acronym the MOCO uses for it) the rear cylinder shut down. On the 08-09 Touring models the rider can toggle it on and off on the fly. From 07' down, the bike has to go to the dealer and let the service dept down load this option....I think its free the first time, either on or off. After that you pay. That is what I would call a active engine cooling system.....the oil cooler is passive.

Personally I think actual engine temps, and more so combustion chamber/cylinder head temps are what are the most critical.
Anyhow.....a oil cooler cant hurt unless your taking too many very short trips and the condensate dont burn off. Or....one of the lines springs a leek.

 

Sure seems to be lots of differing opinions on this. I have read the magazine with the article from Donny as well. I have also contacted Fatbaggers for their opinion on this issue because they are selling their Baggers with Jim's 120 engines with the Chin Fairings installed and backing the bikes with a full 3 year warranty. What they told me is that they found through their testing that a Oil Cooler was not necessary so that is why they are not installed on the bikes they sell. They said they have bikes all over the country and are not having problems with the engines.

 

hmmmmmm..............100% of my harley is black.

 

too hot of oil can be bad for your engine...but too cold of oil can be just as bad if not worse....oil gets thick and is slow to transfer heat from bearings and all moving parts......must have a balance..