Sportster Models 883, 883 Custom, 1200 Custom, 883L, 1200L, 1200S, 1200 Roadster, XR1200, and the Nightster.
Sponsored by:
Sponsored by:

Explain differnce between air cooled and water cooled

Thread Tools
 
Search this Thread
 
Old Jan 7, 2010 | 11:34 AM
  #1  
lizdc's Avatar
lizdc
Thread Starter
|
Elite HDF Member
Joined: Nov 2009
Posts: 3,938
Likes: 23
From: MD just outside DC
Default Explain differnce between air cooled and water cooled

Ok I am going to show that when it comes to how engines work I have little information. I do know that harley's are air cooled not liquid cooled. I also know this is important to many of you.
Can you guys explain the differences to me. I didn't want to hijack the thread about a liquid cooled sportster to get understanding of this.
I love to understand how and why certain things work. This is esp true of my bike. I have been on the back of a liquid cooled cruiser before but have never ridden one.
Any info would be helpful.
 
Reply
Old Jan 7, 2010 | 11:42 AM
  #2  
michaelmartin's Avatar
michaelmartin
Road Captain
Joined: Jun 2009
Posts: 574
Likes: 3
From: Toms River, New Jersey
Default

Air cooled is when the engine is cooled by the air as you ride. That's why in traffic or on slow runs, you can run hot.


Liquid cooled is when the engine has a radiator and a anti-freeze/coolant keeping the engine at a correct temperature, like your car.
 
Reply
Old Jan 7, 2010 | 11:43 AM
  #3  
Flatlander's Avatar
Flatlander
Road Warrior
Joined: Jul 2006
Posts: 1,416
Likes: 0
From: East Central Illinois
Default

Not being a smart@ss Liz. But how detailed do you want. The basic difference is that water cooled is like most cars. Has a radiator and hoses and a water pump pumps coolant through water jackets in the engine and through the radiator. As the coolant goes through the radiator it is cooled and goes back through the engine, where the cooled coolant (cool isn't it) reduces engine temps and picks up heat and runs back through the radiator. Air cooled (like your harley) has multiple cooling fins, when air passes over these fins it dissipates the heat-Pulls the heat from the engine(air cooled). Generally liquid cooled engines run cooler and therefore have the ability to produce more power per cubic inch than air cooled.
 
Reply
Old Jan 7, 2010 | 12:14 PM
  #4  
lizdc's Avatar
lizdc
Thread Starter
|
Elite HDF Member
Joined: Nov 2009
Posts: 3,938
Likes: 23
From: MD just outside DC
Default

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. 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?
 
Reply
Old Jan 7, 2010 | 12:22 PM
  #5  
will227457's Avatar
will227457
Road Master
Joined: Sep 2006
Posts: 1,037
Likes: 4
From: SF BayArea
Default

Originally Posted by lizdc
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. 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?
Guys like that classic air cooled look, and sound

think of it if HD came out with a water cooled 1200cc engine you'd have a V-rod.....
 
Reply
Old Jan 7, 2010 | 12:34 PM
  #6  
oinker02's Avatar
oinker02
Banned
Joined: Jan 2009
Posts: 1,551
Likes: 6
Default

The reason you will soon see more HD's watercooled like the V-Rod is tightening EPA mandates....You can kick n scream all you want, but it's coming.

The reason is that watercooled engines tend to run at a more stable temp and can be tuned to run cleaner. Air cooled engine temps swing from hi to low depending on your speed and the outside air temps so they are hard to tune cleanly.

The upside is you can expect more power per cubic inch and an engine that will run longer tween rebuilds.
 
Reply
Old Jan 7, 2010 | 12:35 PM
  #7  
lizdc's Avatar
lizdc
Thread Starter
|
Elite HDF Member
Joined: Nov 2009
Posts: 3,938
Likes: 23
From: MD just outside DC
Default

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.
 
Reply
Old Jan 7, 2010 | 12:42 PM
  #8  
Maimas's Avatar
Maimas
Road Warrior
Joined: Feb 2009
Posts: 1,661
Likes: 0
From: East Northport, NY
Default

I think the reason people state that it wouldnt be a Harley, is because its what differs Harley from many metric bikes. Same reason why you wont see a gear indicator on an HD.
 
Reply
HD Forum Stories

The Best of Harley-Davidson for Lifelong Riders

story-0

7 Times Harley-Davidson Chucked Tradition Out the Window

 Verdad Gallardo
story-1

7 Surprising Harley-Davidson Products that Are Not Motorcycles

 Verdad Gallardo
story-2

8 Best Harley-Davidson Motorcycles Ever

 Pouria Savadkouei
story-3

10 Worst Harley-Davidson Motorcycles Ever

 Pouria Savadkouei
story-4

Killer Custom's Jail Break Is The Breakout That Refused to Blend In

 Verdad Gallardo
story-5

Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?

 Verdad Gallardo
story-6

Harley-Davidson Reveals Super Cool Cafe Racer Concept

 Verdad Gallardo
story-7

Engraved Rebellion: Inside Bundnerbike's Glam Rock II

 Verdad Gallardo
story-8

10 Motorcycles You Should Never Buy

 Joe Kucinski
story-9

10 Things Harley-Davidson Needs to Fix in 2026

 Verdad Gallardo
Old Jan 7, 2010 | 12:43 PM
  #9  
oinker02's Avatar
oinker02
Banned
Joined: Jan 2009
Posts: 1,551
Likes: 6
Default

Originally Posted by lizdc
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.
There is no reason watercooling should change the exhaust sound of any Harley. As it stands now, the EPA has mandated that no motorcycle can emit more than 80db sound levels, so it's the EPA who is changing how scoots sound.....An air cooled scoot sounds no different than a watercooled scooter.

The radiator can be concealed quite well....Go look at the new Honda Fury to see how they do it.
 
Reply
Old Jan 7, 2010 | 01:38 PM
  #10  
SportyPig's Avatar
SportyPig
Ultimate HDF Member
Joined: Jul 2006
Posts: 6,478
Likes: 12
From: Nashville, TN
Default

Originally Posted by oinker02
The reason you will soon see more HD's watercooled like the V-Rod is tightening EPA mandates....You can kick n scream all you want, but it's coming.
I'll do my kicking and screaming in the voting booth, and out on the campaign trail, thank you. Remember Helmets used to be required in almost every state. Politicians understand votes.
 
Reply



All times are GMT -5. The time now is 07:12 AM.

story-0
7 Times Harley-Davidson Chucked Tradition Out the Window

Slideshow: Harley-Davidson built its reputation on nostalgia, but every so often, the company took a hard left turn into the future.

By Verdad Gallardo | 2026-05-20 11:18:19


VIEW MORE
story-1
7 Surprising Harley-Davidson Products that Are Not Motorcycles

Slideshow: The bar-and-shield logo shows up on far more than motorcycles, some of the company's most unexpected products have nothing to do with riding.

By Verdad Gallardo | 2026-04-29 16:50:35


VIEW MORE
story-2
8 Best Harley-Davidson Motorcycles Ever

Slideshow: Not every Harley gets it right, but these are the ones that genuinely earned their reputation.

By Pouria Savadkouei | 2026-04-15 14:23:21


VIEW MORE
story-3
10 Worst Harley-Davidson Motorcycles Ever

Slideshow: From the troubled AMF years to modern misfires, these bikes earned reputations for reliability issues, questionable engineering, or disappointing performance.

By Pouria Savadkouei | 2026-04-01 20:01:09


VIEW MORE
story-4
Killer Custom's Jail Break Is The Breakout That Refused to Blend In

Slideshow: Killer Custom's "Jail Breaker" build focuses more on stance and visual aggression than mechanical overhaul.

By Verdad Gallardo | 2026-03-18 19:20:32


VIEW MORE
story-5
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?

Slideshow: The Swiss custom shop has taken a Harley Softail and stretched it into something so long and low that it looks closer to a rolling sculpture than a conventional motorcycle.

By Verdad Gallardo | 2026-03-07 16:15:30


VIEW MORE
story-6
Harley-Davidson Reveals Super Cool Cafe Racer Concept

Slideshow: Harley-Davidson's new RMCR concept revives the café racer formula with modern hardware-and it may be exactly the reset the company needs.

By Verdad Gallardo | 2026-03-04 12:23:37


VIEW MORE
story-7
Engraved Rebellion: Inside Bundnerbike's Glam Rock II

Slideshow: A standard cruiser becomes an intricate metal canvas in the hands of a Swiss custom house known for pushing Harley-Davidson platforms far beyond their factory brief.

By Verdad Gallardo | 2026-02-24 18:19:44


VIEW MORE
story-8
10 Motorcycles You Should Never Buy

Slideshow: There is no shortage of great motorcycles to buy, but we would avoid these ten.

By Joe Kucinski | 2026-02-19 14:50:51


VIEW MORE
story-9
10 Things Harley-Davidson Needs to Fix in 2026

Slideshow: Harley-Davidson's challenges aren't abstract; they show up in dropping shipments, shrinking dealer traffic, and strategic decisions that aren't yet translating into growth.

By Verdad Gallardo | 2026-01-13 18:33:17


VIEW MORE