Explain differnce between air cooled and water cooled
Grand HDF Member
Joined: Jul 2007
Posts: 4,007
Likes: 126
From: Manassas, VA
Besides the look factor of a radiator (which is a large consideration), it's adding another system to the bike that needs maintenance and/or could fail - catastrophic failure is a possibility.
Keep the bike simple and easy to work on.
Keep the bike simple and easy to work on.
Cruiser
Joined: Jan 2008
Posts: 213
Likes: 1
From: The Suncoast (FLA)
Much in life is either a trade or a compromise.
Air (and oil) cooled motors are typically lighter and less complicated, lacking radiators and thermostats, water pumps and water. Therefore less maintainance, less to fail. But they suffer from hot spots. Areas that don't have cooling fins and less exposure to moving air when going slow. They can get very hot and lose HP as a result and suffer excess wear in the hot spots. Air cooleds also warm-up slower on cold days and while cold is when a motor suffers the most wear and generally (although many will argue) are not expected to live as long as a result. It is also difficult to cool any motor at extreme speeds. Even the sport bikes with radiators need bigger radiators for racing to keep from overheating.
Compromise. If you go real fast, you had better not wear your tassles!
The best power-to-weight ratios, least moving parts etc. are found two-strokes motors. Like chainsaws... but that's another thread.
Air (and oil) cooled motors are typically lighter and less complicated, lacking radiators and thermostats, water pumps and water. Therefore less maintainance, less to fail. But they suffer from hot spots. Areas that don't have cooling fins and less exposure to moving air when going slow. They can get very hot and lose HP as a result and suffer excess wear in the hot spots. Air cooleds also warm-up slower on cold days and while cold is when a motor suffers the most wear and generally (although many will argue) are not expected to live as long as a result. It is also difficult to cool any motor at extreme speeds. Even the sport bikes with radiators need bigger radiators for racing to keep from overheating.
Compromise. If you go real fast, you had better not wear your tassles!
The best power-to-weight ratios, least moving parts etc. are found two-strokes motors. Like chainsaws... but that's another thread.
Last edited by Sundog; Jan 8, 2010 at 12:05 AM.
Road Captain
Joined: Apr 2009
Posts: 610
Likes: 5
To add:
Water cooling also allows tighter tolerances and there for higher performance. As well as has been mentioned water cooling will always have advantages over any aircooled motor. The extra hardware needed is a small price to pay from all the benefits gained.
Water cooling also allows tighter tolerances and there for higher performance. As well as has been mentioned water cooling will always have advantages over any aircooled motor. The extra hardware needed is a small price to pay from all the benefits gained.
Outstanding HDF Member
Joined: Jul 2007
Posts: 3,143
Likes: 71
From: Wichita, Kansas
I understand the basics of what it is so I get that on liquad cooled it is like a car has some version of a radiator. Sometimes I am not super clear on what I am asking sorry. In my defense I always understand it in my head.
...
I don't understand why it is a big deal.. That is what I am trying to understand. From everything I have read and seen over teh years it is something that gets people really in an uproar. So that is what I am trying to understand is why is air cooled better.
... I don't understand why it is a big deal.. That is what I am trying to understand. From everything I have read and seen over teh years it is something that gets people really in an uproar. So that is what I am trying to understand is why is air cooled better.
Air-cooled engines are the essence of a Harley, some say. (When the V-Rod came out, I couldn't believe the uproar and anger over the use of liquid cooling. One old-timer I know said he would never buy another Harley because of this. So he buys a Honda VTX.)
What we would loose or gain if Harleys were ever liquid cooled. I am sure there is a reason and I would like to understand it. Because I doubt anyone would get really upset if Harley offered a new color paint so there has to be a major impact if this every changed. So what is that impact?
There is much to gain with liquid cooling. Liquid-cooled engines are higher powered, quieter and their emissions can be more easily controlled, because a liquid-cooled engine is more temperature-stable and is built using tighter tolerances.
If Harley wasn't under the EPA gun, you would probably never see an air-vs-liquid debate.
Last edited by F4Phantomsphorever; Jan 15, 2010 at 04:29 AM.
Road Master
Joined: Dec 2007
Posts: 889
Likes: 1
From: Long Island, New York
My eye starts to twitch everytime I see that Harley jug of coolant at the dealer. I had to break down and but a bike with fuel injection but I will be damned if I am ever going to ever buy a water cooled Harley. Just my opinion from a stubborn middle aged fart!
Is that the two things it would impact ? The sound of the bike and the look by having to add the radiator? Is there anything else it would impact? I am not trying to be a smart *** I just want to understand it. The reason I ask if because I have seen threads on this board where people said they wouldn't consider a bike still a harley if they went liquid cooled. That seemed like really strong statement so I want to understand why this seems to be a line in the sand.
Horsepower: it takes extra power to turn the waterpump and push that coolant through the system, that power is taken away fron the wheel.
also factor in added maintenece costs, Checkign coolant, replacing blown/swollen hoses, radiator damages *pin holes,cracks etc* as well as the possiblity of freezing the coolant in the winter, messy clean ups etc
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Road Warrior
Joined: Apr 2009
Posts: 1,800
Likes: 414
From: Ellensburg, WA
Bring on the water cooled baggers. W/lowers the radiator will be pretty non de-script. The cooler running and ability to build more power, easily, is a big plus to water cooled. Have you ever heard a v-rod with engine work and a good set of dual pipes? wouldn't know it was water cooled. As far as problems with water cooled systems, the metrics don't have any more problems than air cooled. Would you rather drive a Corvair or old VW, or a Cadilac?
Last edited by 1plumr1; Jan 14, 2010 at 05:23 PM.
Road Master
Joined: Dec 2007
Posts: 889
Likes: 1
From: Long Island, New York
I would rather ride an air cooled Vtwin just the way I have been for all of my adult like. This radiator talk is making my eye twitch again....