vintage liquid versus air cooled engines

john221ex said:

Also noteworthy is that one of the most durable motorcycles still retains air cooling: BMW.
John

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I guess the past 25 plus years of water cooled bikes haven't proven to be durable. :think:

Okiewan said:

Don't be throwin' in fact, we like the "big business" excuse for everything.

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Now thats a quote I'm going to remember! ;)

The air cooled bikes dont cost too much to rebuild but, has alot less power then a liquid cooled.

John221ex, I don't want any water cooling on my bikes either, but an air cooled 125 noticeably loses power when it gets hot.Even 250s will lose power,if you run them very far in deep sand, or long slippery uphills.

I haven't desert raced in several years, but they always used to run us through about six miles of deep sand wash. My 250 Elsinore would be totally fragged by the end of those washes. Just didn't have quite enough zing to get up and ski on top of the sand, like the open class bikes could. Had to plow through it.

Commando, I hear you, but I ran in exactly those conditions and never had an issue. Of course, the Pentons and KTMs had huge fins, which probably helped a great deal.

Badgerman: I guess you like fooling with water leaks, hoses and paying for $500 radiators. I would rather ride.
Unless you are a pro rider, I bet you are no faster on your overpriced water-pumper than I on my XR. Try thinking for yourself instead of just buying into whatever hype comes along. This sport is far more susceptible to that than is prudent.

Okiwan: ditto.

John
As a Porsche guy myself, I think if porsche were able to keep air cooling for the 3.4l 996 engine, they would have. I think they cited emissions, fuel economy, consistent output and durability etc for going to watercooling. Don't forget that even the mighty 959 had water cooled heads way back in 84.

As someone who has owned a big bore/cammed 912, I can tell you for sure that it ran better when the oil temp gauge was pointing cooler.

On a side note - as I'm only 28, I am on the young side of those old enough to remember a starting line full or aircooled bikes. Is it me or were they much louder than watercooled 2 strokes? I remember cowering in fear of my neighbors' 83 Maico 490.

That was just the Maico 490. A beast of a machine. Mufflers may have improved a bit, but the bikes were not really louder. However, I have seen a line of MX bikes in the old days with some having no muffler attached at all.

old bikes are way loud, my 1982 rm125 with dg pipe and silencer is insane i can hear it over a train.

john221ex said:

I guess you like fooling with water leaks, hoses and paying for $500 radiators.

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Never had a water leak and have never bought a radiator in 35 years of riding.

john221ex said:

I bet you are no faster on your overpriced water-pumper than I on my XR.

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I’ll bet you are wrong. :rotfl:

john221ex said:

Try thinking for yourself

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Try thinking about this. Why do you suppose an engine loses power when it gets hot? Now……..when it gets hot and starts losing power, what do you suppose is happening, internally, to all those moving parts that come into contact with each other (hint, friction and heat are related)? So…..don’t you think that it is good to have the best, most consistent cooling system that you can for your engine?

There’s nothing wrong with an XR250. I own one myself as they are great trail bikes (they also run hotter than hell if you ride them hard). However, to go off claiming that the entire riding public is misled and are only lining the OEM’s pockets by wasting their money on water cooled bikes is crazy :think:

Commando, I hear you, but I ran in exactly those conditions and never had an issue. Of course, the Pentons and KTMs had huge fins, which probably helped a great deal. NOPE! Its because they handled the sand better! Ain't no way an aircooled bike is faster, more reliable or cheaper to operate!

Old dirt bikes were a lot louder than modern bikes, in part because the cooling fins radiated a lot of sound that the water jacket muffles. Plus the fins themselves vibrated, making a ringing sound. most of the factories, at least on street 2 strokes,put little rubber wedges between the fins to help cut down on the ringing.

I don't know what part of the Arizona desert you guys were riding in,in the early '70s but I can only remember a few Pentons(no KTMs yet)running desert races,and they were not competitive, in the sand, or elsewhere(great woods bikes, I'm sure!).Huskys, Maicos, Bultacos,Ossas,YZs, and Elsinores were all in the hunt.I remember a couple of fast AJSs, and one guy on a Greeves 250 with leading link forks, that used to smoke all the other 250s for a while.Suzuki and Kawasaki did not have real dirt bikes yet.All the 250s had trouble with getting hot in the deep sand.Only a few of the courses were really all that bad,or they would have had a racers rebellion on their hands.

I'm a vintage guy,and I'll keep my air cooled bikes, thank you very much. Y'all can have your liquid cooling. I don't know about maintainance cost, reliability(seems like I see as many DNFs as ever)Big Bidness, and all that other stuff, but I do know that a modern, liquid cooled 250 is a hell of a lot faster than any air cooled 250 I ever rode! :)