Fan vs. Liquid Cooled

[zelek]

I admit...I'm a complete rookie when it comes to snowmobiles so try not to laugh at this one.

Last weekend I jumped on my brother-inlaws liquid cooled Polaris 500 XC and couldn't believe how much more snap it's got than my brothers fan cooled 550 XC Super Sport. What's up with that?? Is it geared different?? I thought the extra cc's in the 550 would make it the other way around.

[Sergeant Slabber]

This has nothing to do with your question since I'm a snowmobile novice as well, but I see that you're from Hawley. Just wondering if you know any of the Omberg's?

[fishkab]

Zelek, The liquid cooled motors have much greater tolerances and thus much more horsepower for the same number of cc's. First choice for me is liquid.. Much more power especially when pulling the otter. Fishkab

[zelek]

Nope...don't know any of the Omberg's. We've only lived here for three years and aren't real plugged in to the community yet. Weird schedules and daily commutes do that I guess. There are a few guys from Hawley on the DL forum who'd probably know them though.

[Sergeant Slabber]

Yeah, I was just curious. They've been around there forever. If you take 10 out of town twards DL and hang a right on 34, they are the first place on the left. They own Ross-co Grain Elevator Company. If you have any questions about sleds, they could definetly answer any of your questions. They're into it big time! Take it easy!!

[Little John]

I haven't looked up up the specs on the two machines that you mentioned but from what I know about sleds and engines; liquid cooled sleds tend to be slower, simply because of all of the extra weight that you're carrying. You have all of the coolant, water pump, rear mounted radiator etc. Now with that being said, a water cooled machine will run more efficiently in varying temperature ranges because it regulates it's own temperature. An air cooled machine is generally lighter and quicker, provided it is set up for the temp. you're running in...Let's not forget about about gearing and how the clutches are set up too...As for the tolerances being different, I'm not sure what that means??? Maybe piston, valve, etc clearances are slightly different because of the wider temperature extremes??? But if both engines are at normal operating temps, I would still expect an air cooled machine to be quicker. But I'll take the extra weight of the water cooled sled for my fishing needs.

[hanson]

A fan sled is going to get its butt handed to it by a liquid cooled sled of equal displacement every single time you race.

That 500 XC is a heck of a sled. It does not surprise me that it surprised you.

Fans are just not meant for performance. You have to remember that the fan is driven by the engine itself and therefore decreases your overall power output. Look back into snowmobiling history and the performance sleds of the early 70s were all free-air (f/a) motors. They didn't even have a fan but rather larger cooling fins on the cylinder heads. During the mid-70s, the manufacturers were switching from f/a to liquid on all of their race sleds. A liquid could cool the motor better which allowed the manufacturers to squeeze more hp out of them.

More hp = higher cylinder head temp = higher demand for cooling.

Fans don't run very well in warm air temperature either since you are trying to cool the engine off with warmer air.

[Little John]

I guess I stand corrected and the extra 60-75 pounds of weight is overshadowed by the increased horsepower. I'm not a sled performance expert. I just was going on what I was told by my Canadian sled guru's. I did buy a standard track liquid cooled sled two years ago and don't like how heavy it is and how easy it is to get stuck in deep snow or slush. But it is very fast...

Now I'm in the market for a long track 2-up machine for ice fishing use only. So which one will be better in the snow and slush, a fan or liquid cooled machine? What about the even heavier four strokes??

[hanson]

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Now I'm in the market for a long track 2-up machine for ice fishing use only. So which one will be better in the snow and slush, a fan or liquid cooled machine? What about the even heavier four strokes??

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John- 2 words... Arctic Cat Bearcat Well... maybe thats 3 words. Oh well. Bearcat is at the top of my list! Jim Hudson runs a Bearcat and I've seen it in action. Very nice sled! Most of the big shot Ice Team (Genz & Bro & company) guys are running Bearcats as well.

Concerned about weight of the 4 stroke? I'm not sure if I'd worry about it. You can drive them off of the trailer in reverse but may end up in some trouble if you "bottom out" in deep slush. Hopefully the wider track will save you if you really get into that kind of a slush problem.

[lots of luck]

Quote:

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I admit...I'm a complete rookie when it comes to snowmobiles so try not to laugh at this one.

Last weekend I jumped on my brother-inlaws liquid cooled Polaris 500 XC and couldn't believe how much more snap it's got than my brothers fan cooled 550 XC Super Sport. What's up with that?? Is it geared different?? I thought the extra cc's in the 550 would make it the other way around.

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I am not familiar with Polaris, but I do know I had a liquid cooled 1994 Arctic Pantera 550c.c. (rated at 80 h.p.) and a liquid cooled 1998 ZL 500c.c. (rated at 97 h.p.). The ZL 500 had the reed valve assembly on the intake also. Much more snappier and powerful.

Arctic Cat's Z570 (fan cooled) are only rated at 70 h.p.

Liquid cooled is where the power is from my experience.