Engine longevity: air/oil vs liquid cooling.

[Holocene]

Do the newer liquid cooled engines tend to last longer than air/oil cooled engines Suzuki used to use? Assuming all routine maintenance is followed?

[shpielers]

Assuming they're both being ridden the same?

Oil cooled bikes have higher tolerances because they heat up/cool off more and the metal needs more room to expand/contract. So I'd imagine that helps them with longevity a bit. Water cooled can eke out more power though. Not actually sure which should last longer, definitely interested in anyone who has a knowledgable answer as opposed to my "...der..."

[TRPUT]

Suzuki - and plenty more - still use air-oil cooled engines. You have to remember they were designed that way. It's not a water cooled engine without the water cooling. Tolerances, metal type and thicknesses, gaskets, oil passages and capacity etc. are part of the design process. There are plenty of oil-air cooled engines with a reputation for being "bullet proof" - the Kat being one of them, the BMW flat twins, the big Moto Guzzi Vs ... Air-oil cooled engines have less to go wrong. No water pump, additional plumbing and seals, radiators, thermostats ... Internal corrosion is not an issue. In the extreme heat of outback Australia, air-oil cooled engines are the preferred choice of many because they can handle the heat. Engines designed to operate within a smaller temperature range can struggle when the cooling can't achieve that - ie extreme heat or cold.

In a way, it's a little like diesel vs petrol. Diesel engines are a lot heavier and a lot more robust than similar displacement petrol engines to cope with the higher compression ratio. They can then burn crap, less refined fuel, haul heavier loads, gain better economy and still easily outlast a petrol equivalent.

Water cooling allows better control of operating temperature within reason. This therefore allows tighter tolerances, more accurate fueling and higher combustion efficiency ... theoretically - more power and better economy.

Longevity??? In a like vs like comparison, because each was designed to be what it is - there is probably little difference. But with that additional cooling system in water cooled engines, there will be more maintenance to prevent / cure over-heating, leaks, corrosion, electrolysis ...

[arsenic]

In the KR member world a water cooled engine wouldn't last nearly as long as an oil cooled engine. They need maintenance, which costs money. Some of the jury rigged mechanical what not that goes down here an a daily basis would not work on modern technology.

[Holocene]

Some of the jury rigged mechanical what not that goes down here an a daily basis would not work on modern technology.

haha that describes my whole bike.

[TRPUT]

I actually like the Moto Guzzi Stelvio. Apart from a batch of faulty rockers in about 2011, these motors are known to run 400 000 miles untouched. Air-oil cooled, longitudinally mounted V-twin with the heads sticking out in the air (no plastic in the way of a 30 minute valve adjustment), easy throttle body synching, shaft drive, massive fuel tank and generally quite basic. To me, less to go wrong is a good thing.

[KAT TOY]

In the KR member world a water cooled engine wouldn't last nearly as long as an oil cooled engine. They need maintenance, which costs money. Some of the jury rigged mechanical what not that goes down here an a daily basis would not work on modern technology.