Air-cooled vs liquid-cooled.

[avgas]

The reality is that it's not worth worrying about... as far as reliabilty is concerned, water cooling has proven sufficiently reliable that after a billion odd cars produced, they're still using it.

In all honesty i can both dissagree, in an enclosed space water cooling is the best thing since sliced bread.
But air cooling in its defence did not get a fair trial - the classic i can think of it the VW. How effective would a harley be if the Engine was sheilded behind a big wall and go no air?
From electrical cooling perspective, they use both (well oils instead of water obviously), but still a great number of electrical cooling paths a air and work well.
Its one of those annoying things where time will tell. Lets see the ratio of GSXR1000's vs GSXR1100's in 50 years time.
As for me, i think both have disadvantages - i'll ride either.

[Ixion]

Yes but try making decent fins to work on a water cooled bike. Also water cooled bikes are only as good as the pump (in most bikes water pump = bad quality as you know), oil convection cooling only fails when the law of physics fail.

I never trust those things. Look how many bikes break the speeding laws. Stands to reason some of them will break the physics laws too.

[Forest]

In all honesty i can both dissagree, in an enclosed space water cooling is the best thing since sliced bread.
But air cooling in its defence did not get a fair trial - the classic i can think of it the VW. How effective would a harley be if the Engine was sheilded behind a big wall and go no air?
From electrical cooling perspective, they use both (well oils instead of water obviously), but still a great number of electrical cooling paths a air and work well.
Its one of those annoying things where time will tell. Lets see the ratio of GSXR1000's vs GSXR1100's in 50 years time.
As for me, i think both have disadvantages - i'll ride either.

The VW engines rely on big rubber seals to form an air box for the cooling system.

Works great until the rubber bits start to perish.

[Timber020]

In all honesty i can both dissagree, in an enclosed space water cooling is the best thing since sliced bread.
But air cooling in its defence did not get a fair trial - the classic i can think of it the VW. How effective would a harley be if the Engine was sheilded behind a big wall and go no air?
From electrical cooling perspective, they use both (well oils instead of water obviously), but still a great number of electrical cooling paths a air and work well.
Its one of those annoying things where time will tell. Lets see the ratio of GSXR1000's vs GSXR1100's in 50 years time.
As for me, i think both have disadvantages - i'll ride either.

The VW had something like 65 years of fair trial, and its times since gone. Its past technology, and better things are now here.

In 50 years your going to be more likely to find a working typewriter than a 2008 pc, but its hardly a reflection of which is better. Simplicity is a big advantage when it comes to long term longevity, an axe vs a chainsaw, gramaphone vs a cd stacker stereo.
But we cant live in a world based on nostalgia, there will always be people that wish we still made mk3 cortinas, 1932 indians or p51 mustangs.
Liquid cooling is the better technology, its so common because it works so much better than the alternatives.
The GSXR's left oil cooling when it proved to be holding it back in developing a better machine. If they had stuck to the simpler technology they would have been left behind, much like an American motorcycle company which is now being dragged kicking and screaming, along with its customers, to the realities of evolution and modern times. (water cooling coming real soon to a Harley near you)

[scumdog]

(water cooling coming real soon to a Harley near you)

Not in MY gargre sunshine but yeah, I know they're on their way, noise and air pollution regulations are too hard to meet with an air-cooled engine.

[Edbear]

The VW had something like 65 years of fair trial, and its times since gone. Its past technology, and better things are now here.

In 50 years your going to be more likely to find a working typewriter than a 2008 pc, but its hardly a reflection of which is better. Simplicity is a big advantage when it comes to long term longevity, an axe vs a chainsaw, gramaphone vs a cd stacker stereo.
But we cant live in a world based on nostalgia, there will always be people that wish we still made mk3 cortinas, 1932 indians or p51 mustangs.
Liquid cooling is the better technology, its so common because it works so much better than the alternatives.
The GSXR's left oil cooling when it proved to be holding it back in developing a better machine. If they had stuck to the simpler technology they would have been left behind, much like an American motorcycle company which is now being dragged kicking and screaming, along with its customers, to the realities of evolution and modern times. (water cooling coming real soon to a Harley near you)

Unfortunately, nostalgia ain't what it used to be! Well put! As much as we may like simplicity it won't last forever.

[Ixion]

That is a good point. The increasingly onerous emission rules are easier to meet with a water cooled engine, simply because the engine temperature can be held fairly much constant, whereas an air cooled engine, the temperature will go up and down like mad. When designers are struggling to meet the rules, one less variable to have to deal with is a big thing. Air cooled engines CAN meet emission standards, but it's harder.

[Coyote]

And you've just reminded me that early Suzukis (TS250 for one) had rubber chocks wedged in the fins to shut them up a bit. Didn't seem to make any discernable difference when they were taken out though.

So that's what they're for! I've always wondered that after seeing a few bikes with them. They look dorky

[Coyote]

So are Buells reliable being air cooled, or are they not up to par with the Japanese yet?

Pretty keen on a XB12 S or R if I could ever afford it. Yet to test ride one though, was keen on a Monster till I had a go on one.

[xwhatsit]

whereas an air cooled engine, the temperature will go up and down like mad.

They also require a richer mix, right? Which would mean more unburnt fuel and gas out the exhaust.

[Ixion]

Traditionally, yes. Though the richer mix requirment is basically just because they can get honking hot. Lean mixture plus hot = BadThingsHappen.

But, modern air cooled engines have tackled this. For instance the new Lean Burn Enfields.

[Motu]

There are plenty of air cooled engines out there doing the hard hards in the industrial and agricultural worlds,working for their living,not as some playboy's toy.And I'm not talking lawnmowers,although they are a good example of KISS.When they have to run constant hours in cold,heat,dust with zero maintenance,forced air cooling has been proved to be cost effective....and being cost effective is how you run a business.I don't know if Duetz still do air cooled diesels,but they were top of the line,and very quiet too.

It's all funneling into emissions and ecconomy - if they won't fit through the small round hole,then they drop to the floor as failures.Doesn't mean they were bad designs....it's just that they ''failed to meet objectives''.

[Ocean1]

So are Buells reliable being air cooled, or are they not up to par with the Japanese yet?

They're forced-air cooled, a rather large fan, (thermostatically speed controled) means there's always an airflow appropriate to cooling requirements. On mine it seems never to run at cruising speeds, it often kicks in at low speed at the lights and usually at high speed for a minute when you shut down.

It's probably as accurate as you'll get with air cooling. Cooling is really an issue linked to energy output and combustion efficiencies, if you want maximum HP from any given displacement you're probably going to need liquid cooling because there's limits to the cooling surface area you can build into a small engine. It used to be common to riddle the fins of air-cooled bikes with holes, to up the surface area to help deal with extra HP. If, however, displacement is irrelevant then extra capacity is a good way to make power, and then the advantages of air cooling make sense, (at least to me).

At 100hp odd the Buell's reasonably low stressed compared to the big water cooled in-line 4s, but it does make at least the same torque, and that from very low revs. For me that engine is part of a package that's almost uniquely suitable for medium-speed performance. Fun at legal speeds, (or at least non-walk-home speeds) is important. I don't think the XB12 compares badly to the liquid cooled alternatives with regard to life expectancy.

[Coyote]

At 100hp odd the Buell's reasonably low stressed compared to the big water cooled in-line 4s, but it does make at least the same torque, and that from very low revs. For me that engine is part of a package that's almost uniquely suitable for medium-speed performance. Fun at legal speeds, (or at least non-walk-home speeds) is important. I don't think the XB12 compares badly to the liquid cooled alternatives with regard to life expectancy.

Sounds good. Worth taking one out for a test ride then.

I've started to value reliability a bit more than performance now after dealing with a less than reliable watercooled V4. I'm looking at getting an XR650 since of their rep for being bulletproof plus it backfires like a shotgun and wheelies easily

My Dad values reliability and had an XR500 when he was my age.... I'm turning into him

[xwhatsit]

XR500

Lmao, because that's the most reliable engine ever produced

All the issues with the XL250S/250RS motor, but twice the capacity!


The drilling of holes in fins interests me. I would've thought this would reduce heat transfer from the bore/head outwards?