This time of year, I see a lot of people wanting to make sure that their bike does not overheat. If you own an American bike, and it's not a V-Rod, you've got an air-cooled motor. Most of our metric bike friends on the road, and the V-Rod, have water-cooled engines. As basic as this sounds, either water and air or oil and air must cool your bike's engine. Why? I'll tell ya. Because you are being propelled down the road by an internal combustion engine. Combustion (the explosion) of your fuel (gasoline) moves the pistons in your motor, which generates heat. Then on top of that, the movement in close proximity of the internal components of your motor (rods, pistons, gears and the like) creates friction, which generates more heat. If you don't control the heat associated with these mechanical functions, all this metal stuff in your motor will just melt together and you'll end up cursing on the side of the road. Not good.

If you were reading closely, the common cooling feature found in either water-cooled or air-cooled engines is AIR. Air is the common denominator that cools your motor, whether you have just oil running through it, or oil and circulating water (anti-freeze coolant) flowing though pockets inside your crankcase. The ultimate goal is to dissipate the heat generated in your motor into the atmosphere.

If you've got a water-cooled engine, you?ll be sporting a radiator somewhere on your machine. Normally it's a rather ugly, but required, piece of gear aptly named because it radiates the heat captured in the water that's circulating through your motor. A typical radiator is composed of thin circuits of compressed tubing through which the water or "coolant" flows. Air passes by the radiator fins and the heat energy is dissipated into the atmosphere so the coolant can once again flow into the motor to cool the hot cylinders. If your vehicle is sitting still and no air is flowing through your radiator, heat will build up and you?ll overheat your motor. To alleviate this condition, vehicle manufacturers place electric fans in front of your radiator to assist with the flow of air to keep the cooling process happening. Flowing air is the most important component to transfer the heat. If you?ve got no airflow through your radiator, you'll overheat.

Your American V-Twin is a time-honored, incredibly good-looking design, which incorporates an air-cooled motor. Confused yet? Yes, air does cool your motor, but it's also the oil in your motor that is circulating and dissipating the heat being generated. Most V-Twins have only a 3-quart capacity of oil that circulates in and out of the motor. If you're a quart low on oil, you've reduced your cooling capacity by about 30%. That's why it is very important not to run your bike low on motor-oil; even more so when it's hot out. The oil is also flowing at a relatively low pres sure in your motor. The oil pump, depending on the oil temperature, generates only 5 to 15 pounds of oil pressure. If your oil is extremely hot, you'll lose oil pressure, which results in engine damage. Sounds like you need an oil cooler, right? Well, not so fast. I'm still trying to get to my point here, bear with me.

Air is the key to cooling your V-Twin. That's why your motor has large fins all around the cylinders, which add more surface area. This additional surface area that you see on your Harley-type motor works just like a radiator on the water-cooled motor. Air passes over the fins when you're moving and that cools your engine and it's components, including the oil circulating from your oil tank into your motor. If you've got an oil cooler, it will add an additional "radiator" type contraption to your oil circulation system to dissipate the heat stored in the oil.

As much as you'd like to run out and buy an oil-cooler, I'd advise you to keep your wallet in your pocket. Now I'm finally getting around to my opinion regarding why I think you should skip putting an oil-cooler on yo

 

Why do you suggest opting out in not putting on an oil cooler?

 

I put a Jagg 10 row on my bike 2 years ago, very happy with it.
this summer, a friend put a Jagg 10 row on his 07 Ultra, he's happy

Donny Peterson believes in them, not everyone agrees with his opinion but he's got a LOT more experience than I ever will...

just my opinion....

 

?? post ends before he says why,,bummer

 

Maybe because the post was written 5 years ago?

 

This guy dosent live down in Yuma like me. My Ultra is running way too hot im in the market for one. Any suggestions?

 

best thing you could do for that Ultra is take the lowers off

 

My wife and I ride Dynas. No coolers on either bike while we made our way across the South from Southern California to North Carolina and back...then to Canada in mid summer.
Had 20w60 synthetic oil in both and both bikes ran great in 110 degree heat for days.
I don,t think an oil cooler makes a big difference, if any on a HD.
Yes, you have more oil circulating in the motor but who's to say the cooling is just as good with a properly topped up oil reservoir and good quality clean oil (clean to a degree).
More lines and connections to leak down the road also.
Why does'nt an oil cooler come stock on all air cooled HD bikes?
Cause it's good like it is, that's why.

 

Somewhere in this forum there is a post, with numbers, showing the difference in engine temps with the lowers on and off. It's in one of the several thousand 'Lowers - on or off?' threads.

The engine ran cooler with the lowers on. It seems they direct more air toward the engine. I believe the rider feels more heat with the lowers on.

 

You will never get an air cooled system to work as well as a liquid something like 75% less ability to remove heat.
Oil coolers only do so much after all only one HD has oil cooled head the rest the oil to the head lubes but doe so little cooling not worth looking at.
There is a simple way to make your oil cooler work better when in slow traffic or stopped . That is the time it is just about useless .
Low cost takes a short time to install and works.
http://bigskyfan.tripod.com/id10.html