[Dohmer]

I think your point is that liquid-cooled engines are better. That's a flawed argument.

Better than what?

"Better at managing heat". Okay, but where?
"Better at managing heat in the engine". That's true, but so what!

They are "not" necessarily better (or worse) than managing the heat that the rider feels, although they might be different.

Liquid cooled engines do allow designers more freedom to design the engine, so it's easier to increase rpm, horsepower, etc. etc.

But not everyone (and I suppose almost none of us considering we're in the Indian forum) wants a 200mph plastic machine that sounds like a sewing machine.

There's no "better". A boxer (aircooled) engine is different from the vtwin (aircooled) engine which is different from a liquid-cooled v-twin which is different from all other engine configurations.

The fact that BMW for its entry into cruisers chose an air-cooled power plant shows that the rumours of air-cooled's demise is greatly exaggerated.

It's my understanding that BMW is running a very small run on this platform. I believe that as the Bagger generation dies off so will the big air cooled platforms. Younger generation is efficient minded. And air cooled doesn't fill that space. Just me

 

[GaD57]

Kevin Cameron is probably the most knowledgeable person out there writing about all things technical concerning motorcycles and engines. Follow this link, and there is more than enough to keep your attention for days, and I'm pretty sure that the water cooled vs. air cooled subject is discussed:

Kevin Cameron | Cycle World

www.cycleworld.com

 

[zee]

It's my understanding that BMW is running a very small run on this platform. I believe that as the Bagger generation dies off so will the big air cooled platforms. Younger generation is efficient minded. And air cooled doesn't fill that space. Just me

Time will tell. There are plenty of young people who move into cruisers. Like I said, not everyone wants a machine designed to go 200mph. Some of us prefer torque, quiet engines and simplicity over HP and loud engines.

 

[Gaebril22]

Eh most cruiser bagger guys seem to think if they aren't insanely loud they're doing it wrong... most water cooled engines are quieter anyway. That's why all the baggers complain they sound like sowing machines.

 

[zee]

Eh most cruiser bagger guys seem to think if they aren't insanely loud they're doing it wrong... most water cooled engines are quieter anyway. That's why all the baggers complain they sound like sowing machines.

Exhaust, not the engine. The cruiser guys want to hear the exhaust. Air cooled engines are not loud.

 

[Max Kool]

Air cooled engines are per definition louder than water cooled engines, because they lack the sound insulating water jacket.

(ask any Porsche owner)

 

[K2V2]

If you want better performance, you want a liquid cooled engine. Period.

 

[K9F]

If you want better performance, you want a liquid cooled engine. Period.

Shall we start a two-stroke versus four-stroke thread? 😇😎

 

[Demolition Man]

 

[Dohmer]

View attachment 618813

Sven you need cold one to help wash it down

 

[reinie]

The Harley Davidson Nova project had a radiator under the seat mostly to keep it hidden. I would imagine the hot air was to be exhausted out behind the rider somewhere.

 

[Demolition Man]

Sven you need cold one to help wash it down

Okay,......

 

[Kruzn]

We have our air-cooled 2015 Roadmaster trike, water-cooled '97 Honda Valkyrie and '02 Boss Hoss V8 Trike. The amount of heat coming off the engine is about the same between the RM and the Valk. But if you want HOT, try wrapping your legs around a Chevy V8 in heavy traffic on a 90 degree day! Especially when the fan kicks on on that giant radiator!

As far as performance goes though, we have never had any over-heating issues with the Valk or the Boss, regardless of conditions and the engines never lose power or do anything weird when stuck in traffic on a hot day.

The same cannot be said for the air-cooled 2015 RM. A couple years ago we got caught in stop-and-go, rush-hour construction traffic on an off-ramp and the connecting street. There was no where to get out of the traffic short of pulling over on the shoulder. With no air moving over those big cylinders, the RM got very hot. I started shutting it off intermittently but was concerned about repeatedly cranking the starter. When we finally got free of the traffic we came to an uphill stop sign. As I attempted to pull out of the stop on the uphill grade, the RM stalled. It started back up, but labored hard while cranking. I was able to flog the throttle to keep in running, but it was extremely down on power. I actually thought I had burned up a cylinder. After we got out into the country again, with air moving over the engine, it regained it's power. The engine had obviously overheated to the point where performance was severly affected. A very similar situation happened to us years ago on an air-cooled 1980 Yamaha XS1100. Had to pull over out of the traffic and let it cool down before it would run right again.

Don't get me wrong, we love our RM! But in certain situations water-cooled is superior to air-cooled. After the over-heating experience on the RM we do our best to avoid getting stuck in traffic when riding it. Of course we try to avoid that on the water-cooled bikes too, but more from the comfort aspect and just traffic aggravation, not because of over-heating concerns.

 

[Tile]

I might add that my Raider is almost as fast as the M109R. Slightly larger displacement (113 vs 109), much longer piston stroke, and being air cooled, it doesn't bake my thigh.

There are a lot of factors that go into horsepower. Yes, cooling is one of them. But for air cooled engines, add enough heat sink and the heat transfer is accomplished without a fan blowing the heat on the rider's leg.

Regarding the 111 and 116, I understand removing the cat improves rider comfort. That was one of the first mods I did to my 116.

I'm a torque addict, so longer stroke is my choice.

I also had a Yamaha stroliner 1800 , never got so hot

 

[Dave H]

All arguments aside, this is an unvarnished reality.
1. The Challenger is by far the tourqueiest thing I have ever been on.
2. The Challenger is the least hot bike I have ever been on.

My opinion is that it never gets as hot so it always has less heat to shed.

 

[Dohmer]

All arguments aside, this is an unvarnished reality.
1. The Challenger is by far the tourqueiest thing I have ever been on.
2. The Challenger is the least hot bike I have ever been on.

My opinion is that it never gets as hot so it always has less heat to shed.

To my observation water is not allowed to achieve high operation temps with design therefore lower temps out. Also heat kills

 

[splitt]

The one thing that I think is an advantage in the Challenger is the way they exhaust the radiator heat downward instead of back towards the riders legs and other sensitive areas when the fan kicks on.

 

[reinie]

I think the Gold Wing has two side radiators that vent hot air out the sides away from the rider.

 

[GreatWhite]

I also had a Yamaha stroliner 1800 , never got so hot

A past ride would get so hot gas would be boiled right out of the carb and stall the bike. The fuel pump would continue to feed the carb flowing gas all over the right side of the engine until you turned off the ignition, cooled it off- a Yamaha Roadstar Midnight Star Silverado (what a mouthful). Never forget about it in Dallas and in Maob. Damn hot days.

 

[Baron58]

Air cooled engines will still be made and sold as long as people are willing to buy them. Yes water cooled is better for all the reasons previously mentioned. But the analogy is this. V Twin engines are what air cooled is to water cooled. V Twin engines are less efficient, produce less power per cubic inch or cc than modern inline or opposed engines. But they still sell to the aesthetics and vintage V Twin feel and vibe.
Air cooled V Twin engines have the classic "hot rod" vibe thus their appeal. I know someone who traded in a 2018 Goldwing and he loved that bike, for a Roadmaster, and he was looking for that classic hot rod V Twin vibe. He still missed the superior power he had from his 1800 cc water-cooled engine, but since he doesn't go 150+ MPH anymore he likes cruising on is Roadmaster.