water pump for liquid cooled engine?

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crazykart

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Ok so I'm using a liquid cooled snowmobile engine now, and I'm going to want a way to pump the coolant through the rad and engine, simple enough. I've found one possibility, but was wondering if anyone had any thoughts or suggestions on other possible pumps.

I would really like a sealed mechanical pump that I can run off the jackshaft, but the problem with that is that when not driving it's not pumping.

Another thought is electric, but the prices seems to be crazy.

I would love to find something around $20 that can pump 300 degree coolant..but I doubt it. Anyone know of anything for a decent price that fits the bill?

Rotax engine, I believe a 440 Off a ski-door safari.
 

crazykart

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Yes, but no where near strong enough to push the kind of cooling I'm going to need. The cooling system relied on what's basically a free flowing restriction less "heatsink" on the bottom of the snowmobile that was cooled by both the air generation from the track, and the snow that it would be throwing. To then take that system to a restricted very large radiator would put a huge strain on the built in pump since it's not meant for restrictions. I'm mainly looking for a small auxiliary pump to help handle the load, and keep the flow high enough to keep the engine cool during the summer months. I'm one of those "better safe than sorry" kinda people lol.
 

Badot

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I'm not familiar with snowmobiles or designing water cooled systems, but I can't imagine a radiator would add much restriction unless it's too small...

As far as getting a cheap pump... I'm not sure how much I'd trust a cheap pump. Also, if the water really hits 300 degrees (I assume Fahrenheit) you're looking at around 60psi I think. It's not that it's not doable, it's just there's very few applications like that so it may be very hard to find anything that suits your needs.
 

crazykart

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The passageways of a radiator are pretty small, especially compared to the wide open spaces of the original heatsink style cooling system. The original water pump was designed for volume at low to no pressure, and little restriction.

The whole point of having something that can handle up to 300 degree Temps is to rather be safe than sorry. In an overheating situation the coolant can reach up to 300 degrees. Normal operating temp for the coolant should be between 150-195 degrees depending on the thermostat I use. I just want the pump to not fail if it goes into an overheat situation.

ML-Toys: no I had not even thought about those. Hmmm, 12 volt, rated at the right temps, high flow. Wither would work perfectly. Thank you very much!
 

firemanjim

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If there is only one thing you can say about MLTOYS, you can say,.... He ALWAYS has that Google fired up..... ! :lolgoku:
He IS good at posting good links/info...... :thumbsup:
 

ML-TOYS

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If there is only one thing you can say about MLTOYS, you can say,.... He ALWAYS has that Google fired up..... ! :lolgoku:
He IS good at posting good links/info...... :thumbsup:

Thanks, i always like to help doing research to help others out. There are times i think differently because i am not focused on it as much as the person seeking info. Sometimes you can get focused on a certain way and not be able to seek outside the box.
 

OzFab

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An electric pump may work but, the problem is the electric pump wil spin at a constant speed, the engine will not; a mechanical pump will spin at the same rate as the engine but must be run off the crankshaft or camshaft...
 

Denny

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Your over thinking things the wrong way! :mad2: Every sled I've had has always had a thermostat or restrictor plate in it, Polaris and Artic Cat. You need the thermostat to get the engine up to temperature. The factory water pump will push the water fine as long as you get the air out of the system. Good size radiator and you're good to go. :cheers2:

Denny
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crazykart

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Every sled Ive ever seen has also had this huge heatsink, with plenty of room for water to flow as well, and every radiator had these little itty bitty passages. Ive done some research and the hardest part about using a liquid cooled sled engine is the fact that they overheat quickly. The thermostat will stay in, thats no doubt, but I want something to be able to keep up with the flow as well. I want to be able to redline this, and hot it hard for long periods without blowing it from excessive heat. Believe me, overthinging it would be putting an ice cooling kit in it, or going nitrogen lol.

True an elec pump will spin at a constant rate... unless I make a voltage regulated switch on the throttle that will make it spin up as throttle is increased, but I think it would be just fine as ot would be basically an aux pump. Then again I have enough room on the output shaft to slide a pully in before the clutch driver pully, could run a mechan pump off that without it ever being disengaged Vecause of the clutch not spinning up.
 

Denny

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Those heat exchangers are not as efficient as you might think. They are pretty thick to avoid damage from rocks or Ice that may get flipped up. You need to look at total surface area, tubes and fins. A radiator repair shop could figure out the proper sized radiator for you.

Denny
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crazykart

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Ok, but you're comparing potatoes to pumpkins. I wasn't questioning the efficiency of the heat exchangers, or anything like that.

You would actually be suprised at how well they work though. Yes they are thick, in spots, mainly the exposed areas, but no more than 1/8" thick. This is all moot though.

The passages are about 1/2" to 3/4" square...plenty of flow. The passages of a radiator are around 1/8" to at the very best 1/4" square. It's like trying to fill up a 5 gallon bucket with a garden hose. If the hose isn't kinked it gets filled up quick. If you kink it you restrict flow.

The radiator or heat exchanger isn't at question here. What is at question is the ability of the built in small pump to be able to handle the added pressure and flow requirements to maintain proper cooling. Even then it's not at question because I would rather be safe then sorry and just add a second pump to help take the strain off.

What was at question is if anyone knew of any sufficient pumps as my research was bringing up the same things over and over.
 

firemanjim

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With the right radiator, you should not have a problem, as Denny stated. With the correct # of passages, and surface area, you would actually cool the engine better, than with the original set up. Not to mention, you would be adding more coolant than the original set up had, and that also equates to cooler running. With a large enough surface area, a radiator could cool off the coolant at a much faster rate than the heat sink, even with the huge open passages.
A radiator doesn't restrict flow as much as you think.... My cousins 500+hp (restored) chevelle is a street car and runs cool all day. Had to go up in temp thermostat cuz it was running too cool.
If you're that concerned about flow, why not use a couple car transmission coolers. Mine have 1/2" ID tubes.... And keep my trans about 25-28 degrees cooler than the stock cooling set up, going through the radiator. (how dumb is that? Trans fluid running THROUGH the radiator.....not a separate cooler.... ) and thats ALL I'm using. Go to the junk yard and look for used coolers. Put 2 big ones back to back, and you got a custom radiator. Run the engine and see what temps your getting, both going in and out of the coolers.... You might add a fan, if anything....
 

crazykart

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Ok, let me rephrase. For my peace of mind I want an auxilary pump capable of pumping coolant at high temps. The validity of a radiator is not in question. I already stated I was using a rad in fact, and already have the one I'm using picked out. I want the extra pump for peace of mind for that slim chance that the oem built in pump either can't keep up, or fails completely because of possible strain.

It's like switching your axle from a 1" to a 1 1/4". You know the original probably would never bend or break, but why even take the chance of it happening, and possibly destroying more things with it when you can just prevent it and have that peace of mind now?

I WANT an extra pump. I'm going to use one. I'm not questioning anyones expertise, knowledge, or intelligence. This is purly what I want and am going to do, and am looking for suggestions on possible pumps that will work.

Some things are hard to convey via written word lmao.
 

Monkeyclutch

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An old motorcycle pump may work? I know that for cars there are electric performance pumps but they cost a pretty penny.
Performance radiators are the most effective way of reducing heat, that's why everyone's recommending them.
I'm unsure if snowmobile engines are any different than an engine that's not exclusively used in cold weather but generally cooling system upgrades are done when another upgrade causes excessive heat (higher compression, nitrous, boost, etc...). It's hard to overheat a coolant system with everything working. I'd honestly just buy a brand new stock replacement pump if you're that worried about it failing.
 

Btchin86

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Look at all the goof cart guys putting snowmobile engines in there cart. Most just run a radiator and no extra pump. Radiators run the coolant through multipul passages at ones, not one tube at a time.
 
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