At what speed do you actually run your Snowcat??

Well with my new motor and a fancy set of Snow Trac gears I should be able to go about 35 (but wont). 25 mph should be just fine in the hills!

This is a great thread. We all think that faster is better, when we need to travel several miles. I drive a LMC 3700C with asymm tracks in about 9 miles to a lodge. Pulling up hill is tougher and slower, because we pull a sled full of kids (about 35). It takes about 1 hour and 10 minutes. I think more hp would help to go faster up hill, but your points about driving over rough roads is well taken. The faster you go the more you beat yourself and the machine up. Driving over about a foot of power on top of packed snow is great, but that doesn't happen too often. Also, I go in on a snowmobile when I need to get in faster and cheaper. However, the bumps, dips, and uneven packed snow kills me too. A better suspension is only good if you go slow enough to let it work. Or maybe fast enough to only skip over the tops of the bumps. Lol. Also, faster speeds means that the tracks are trying to throw themselves away from the idler wheels and as some said, that results the tracks hitting underside parts. This is a result of centrifugal force, which gets greater the faster you drive. Basically, if you double your speed you have increased the centrifugal force by 4 times. Centrifugal force is actually related to the mass times the velocity squared, divided by the radius. So the speed at which you are driving is responsible for the force driving the tracks upward and is a function of the velocity squared. So if you are driving at 8 mph, the square of 8 is 64. If you are trying to drive at 15mph, that force jumps to 225 almost 4 times greater). That force is trying to throw the track off of the guiding system and drive links. That is why so many belt drive systems, like lawn mower decks and automobile belts added idler wheels, to counteract that force.

In the automatic transmission or hydraulic drive motor snowcats, do I need to worry a little about the temperature of the fluid. I recently purchased two Thiokol 3700s. They both have the Alis Chamers motors. I don't know which specific motor yet, I will need to look for some plate with the info or pictures that show the difference. If it a four cylinder motor, I am only seeing an AC 433 as an option. I don't know or remember if they have a temp gage for the hydraulic fluid to the drive motors, but I may try to install one if they don't.

Also, I need to look at the manual to see how to switch from high range to low range. That may help to keep the fluid cooler if it gets hot. So much to learn about these snowcats, but it is a lot of fun learning about these machines. I just finished replacing a few tires and wheel bearings. Now that it has started snowing I am about to go play with them in the snow to see what they do.

My wife was ready to shoot me for buying these Thiokols. Little does she know a person approached me yesterday asking if I might want to buy his 1970 Tucker snowcat. I know even less about Tuckers, much less what kind of condition this thing is in. However, I know me, so yes I will be going over to look at it.

I operate a prinoth husky trail groomer in the winter (when we have snow of course). We average 9mph when grooming. Sometimes slower. Sometimes a touch faster but in my 20+ years running a snowcat, I can safely say that speed is NOT your friend in one of these. Sure, I can rev the rpms up to 2500 and dial up the speed to gain maybe 2mph. All I'm doing is increasing wear and tear on the machine and over the span of a 14hr grooming shift, I might save 20 minutes. I'd rather dial the speed back, run it about 2100rpm, and not have to spend hours fixing broken track cleats and busted lights for 3 hrs after my grooming shift.

I agree with you. Other threads I have read suggest reving up the RPMs only shortens the life of your engine. So what is a few minutes saved worth? Not the price of rebuilding the engine and additional wear and tear and pounding on the frame welds, and running gear. Just plan ahead for a little bit longer time to get there. Stripping one of these older machines down to the frame exposed several stress cracks and previously welded cracks and gussets added in a few places. This suggests things were already stressed beyond the metal's ability to handle it over time. Why add to that stress, unless you like stripping things down and need the welding practice.

Our 1200 does about 16-17 before hitting the 4,000 RPM rev limiter. It's pretty happy on smooth snow at about 12. Steep grades with deep snow it barely moves in first gear. But it moves.

There is a Hagglunds BV206 with a transplant 320HP gas turbine swap now on eBay if you really want to go fast.

PJL said:

Our 1200 does about 16-17 before hitting the 4,000 RPM rev limiter. It's pretty happy on smooth snow at about 12. Steep grades with deep snow it barely moves in first gear. But it moves.

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My 1202 with a c6 will do 13-14 wound up according to a GPS. I don't like winding it up like that.

I probably ran mine at 8-ish mph on smooth flat fields with heavy snow base. Slower with moderate and low snow because it was too bumpy. I had a top speed closer to 12/13mph but that was pretty loud and was only viable on smooth ground with a good base of snow

Most of my experience was on corn (bumpy) and soybean (reasonably smooth) fields.

I am in that 8-10 range with the Tucker 443. I totally agree down hill at 15 is get'n a little western.
I have a 3 speed on the tree so most of the time 2nd is the money shot.
Its faster than muscledralics!!!!

I just noticed this is a *BIG AL * thread from the days before meta started feeding dopamine to folks in return for market analysis.....

I run ST4 snow tracs in 4th gear right at the speed when the tips of the cooling fan go super sonic and squeal. in deep loose snow it takes all the power i have and really gets warm in the cabin. snow tracs are the closest to a car like performance as you can get in a cat. with stock gears its something like 19 mph, I make the optional 15 tooth final drive output gears, I get concerned when I run those gears, I have never felt the need to sustain high ground speed.

tuckers, any of them with steel on the ground are happy under 10 mph, Yes I have been clocked at 21 mph with a ski boot stuck under the brake pedal and on the gas pedal, but that was a rodeo event at the midwest snow cat clowder and I won a $2 plastic trophy. ( disclaimer I was passed in the same event by a 40's tucker torpedoe )

NDpilot is spot on in most LMC thiokol OC 12 products.

Imps scoot pretty good but like to porpoise a bit unles they are on firm snow.

Here is a surprise I learned 1 year ago. and to big al I owe an apology, I was a kristi hater back in the day. but then I bought one and late season 23 on firm snow I had the pleasure of putting a gaggle of snow cat owners in their place. a 1642 wide cab tucker with upgraded axles and hans hall smooth bar tracks combined with a Duramax diesel and an over drive trans could not keep up. GPS clocked me over 26 mph and the 1200 cc engine had all it could do to carry the grades.

35 kids in a sleigh would warrant a pretty stout cat to keep it fun for all. I saw a school bus on tracks in sled tv social media feed

Well no one has hit the answer yet, "Drive it as fast as you can afford to fix it"

Speed costs how fast do you want to go

15-20 is plenty.

My Imp will do 60 mph and not break a sweat...on the back of her trailer.