Hydraulic snowmobile

[jjeff]

Hi I am new,
I guess im trying to reinvent the wheel. I recently came across a rolling snowmobile chassis with most drive components removed. My plan is to re power it with a four stroke gasoline engine connected to a hydraulic pump which is connected to a hydraulic motor connected to the jack-shaft which runs into the sealed chain-case this turns the track. I am pretty good at mechanics and fabrication but i don't know much about hydraulics.
The use of the snowmobile would mainly be for off trail utility applications, such as hauling fire wood, dragging a skid, etc If possible and practical I would like to install a quick connect system off the pump for powering things such as a log splitter etc.

Possible issues I can think of are
Power, how big of a pump and motor do I need? Im thinking of going with a variable speed gear pump which increases and decreases flow with engine RPM. The pump would power a hydraulic motor that would smoothly engage and disengage at a certain flow of fluid from the pump are there such things?, The hydraulic motor would also need a valve in order to put the snowmobile in reverse. Are there decent pump and motor setups out there that would fit this application? Speed is sort of an issue also could I get good power and still run the sled at 40 MPH with a setup like this?
cost is another concern to re-power the sled with all new OEM components would cost around 2-3k.

Has anyone here tried something like this?

Thank you for reading, questions, along with any and all input is greatly appreciated.
Jeff

 

[AKKAMAAN]

Hi I am new,
I guess im trying to reinvent the wheel. I recently came across a rolling snowmobile chassis with most drive components removed. My plan is to re power it with a four stroke gasoline engine connected to a hydraulic pump which is connected to a hydraulic motor connected to the jack-shaft which runs into the sealed chain-case this turns the track. I am pretty good at mechanics and fabrication but i don't know much about hydraulics.
The use of the snowmobile would mainly be for off trail utility applications, such as hauling fire wood, dragging a skid, etc If possible and practical I would like to install a quick connect system off the pump for powering things such as a log splitter etc.

Possible issues I can think of are
Power, how big of a pump and motor do I need? Im thinking of going with a variable speed gear pump which increases and decreases flow with engine RPM. The pump would power a hydraulic motor that would smoothly engage and disengage at a certain flow of fluid from the pump are there such things?, The hydraulic motor would also need a valve in order to put the snowmobile in reverse. Are there decent pump and motor setups out there that would fit this application? Speed is sort of an issue also could I get good power and still run the sled at 40 MPH with a setup like this?
cost is another concern to re-power the sled with all new OEM components would cost around 2-3k.

Has anyone here tried something like this?

Thank you for reading, questions, along with any and all input is greatly appreciated.
Jeff

Unless you do this, just for some fun shop hours, this will be the best advice you ever will get on this project....
STOP ANY INVESTMENTS INTO THIS PROJECT NOW!!!


A FEW REASONS....!

***Compared to a regular snowmobile, you will need, at least, twice size motor/engine because of all power losses in the hydraulics and all the extra 250-500lbs of weight you will be adding in hydraulic components and fluid...

***It will cost you much more than buying a better used snowmobile...

***You will need great cellphone coverage in the area you are going to operate this hydraulic-snowmobile, because it will become so heavy, so wont be able to handle a "stuck situation" on your own....


There is a reason why no-one have tried to invent this "wheel for real"....the reason is "common sense".....nothing can beat mechanic belt driven clutch transmission in efficiency and simplicity...
I think there was a project in the 70's, where a torque converter was used....

 

[jjeff]

Hi, Thanks for the input, It is definately a fun project only thats why I mess around with ideas like this, I seem to learn a lot more about things by trial and error and enjoy coming up with new ways to solve problems. I already have 4 operating reliable snowmobiles and just want to try something different. I guess I was just trying to think outside the box. At one time I owned a evinrude snowmobile with a rotary cumbustion engine it had by far the most torque and best fuel economy out of most 2 stroke sleds I owned. yet rotary cumbustion engines never took off. What confuses me is the fact a skidsteer for example weighs 5k+ is powered by a smaller , diesel engine 30-90 hp and uses both gear and varible displacement pumps for not only traveling but moving a ton of dirt. All I want to do is use a single pump hooked to a hydraulic motor to move a 500 lb snowmobile along and have remotes for running stuff like a log splitter. As for getting Stuck I guess ill mount a hydraulic winch on it LOL. For now I will study up on hydraulic systems.
Thanks Again for the input
Jeff

 

[AKKAMAAN]

Hi, Thanks for the input, It is definately a fun project only thats why I mess around with ideas like this, I seem to learn a lot more about things by trial and error and enjoy coming up with new ways to solve problems. I already have 4 operating reliable snowmobiles and just want to try something different. I guess I was just trying to think outside the box. At one time I owned a evinrude snowmobile with a rotary cumbustion engine it had by far the most torque and best fuel economy out of most 2 stroke sleds I owned. yet rotary cumbustion engines never took off. What confuses me is the fact a skidsteer for example weighs 5k+ is powered by a smaller , diesel engine 30-90 hp and uses both gear and varible displacement pumps for not only traveling but moving a ton of dirt. All I want to do is use a single pump hooked to a hydraulic motor to move a 500 lb snowmobile along and have remotes for running stuff like a log splitter. As for getting Stuck I guess ill mount a hydraulic winch on it LOL. For now I will study up on hydraulic systems.
Thanks Again for the input
Jeff

Just for the fun of a hydraulic project, I'd love to see your maiden voyage on a video clip...
I was involved in a hydraulic snowmobile project once (around 1990), but that was a power test bench for snowmobiles (power on the track mat)....we had to skip the hydraulics and go mechanic....there was just to many loose ends in hydraulics, to worry about, all power had to go into heat, and it screwed up viscosity on fluid...bench worked great, but we had to stick with our own horse power units LOL....We used it successfully for comparing engine power between racing machines that my buddy built...one machine had a turbo charger on a 2 cyl two cycle engine....added some good extra horses that way...

 

[jjeff]

Maybe ill be on funniest home videos LOL ....It problaby wont be done for a while If I can make it feasible. Im pretty sure you can find oil coolers to deal with heat issues or maybe even modify the exchangers on the tunnel providing they will hold up to high pressure. Fortunately Im already ahead cause I got the rolling chassis for free. Anyone know of a website, mathematical formula, or reccomendation to help me find wht size, and type of pump and motor are needed and what size gas engine I need to run the pump?
Thanks again
Jeff

 

[David Devuono]

JJeff, to put things in perspective, I am building a hydraulic tracked vehicle and I am shooting for a top speed of 6-8 MPH (27hp 4 stroke 2cyl). For the kind of speed you are looking for, you won't get the rpm range out of a hydraulic motor. You will need some kind of fancy transmission to channel a hi-torque hydraulic motor spining at 300 RPM. Also remember that for example the 40 horse diesel on my farm tractor puts out about 240 ft lbs of torque, compared to a 100 horse snow machine engine putting out 75ft lbs of torque. I believe you are looking at needing to retain the centrifugal clutch, take a hi-torque hydraulic motor (maybe 20hp motor)through a 10:1 step up gear box and then find at least a 30 gpm pump powered off a 50 hp engine. Or you could as other suggest, just hook a motor up to the snowmachine clutch and forget the hydraulics. Hydraulics equal slow. Start by looking at some of the hydraulic stuff at the Surplus Center. Check on the motor specs, IE Max RPM and torque and max GPM. Figure on having a 4 stroke engine 15HP for every 10 GPM flow. Consider that you will need 200lbs of hydraulic fluid and reservior, filters, coolers, motor spool valve, pressure valves, gas engine, tank, hoses. I am guessing $3000-5,000.

 

[Tig]

Very interesting project. As mentioned a couple times already weight is a big problem.
Snowmobiles are very clever in their light weight engineering. Replacing the 2 stroke engine and CVT/clutch defeats most of that.
Figure out how much the finished project will weigh and then practice lifting half that weight to chest height before you venture off trail into deep snow.
Snowmobiles work well because the CVT is tuned to provide optimum torque for the situation. You would have to manually accomplish this with valves, not an easy task especially if your goal is 40MPH. Take some time to consider how a snowmobile "gears" down under heavy load while keeping RPM high. It's a critical characteristic when the going gets tough. Fail and you will be back to lifting the machine out of the hole you dug.
Good luck. Post video.

 

[tungularafishcamp]

I think it would be a great project and would work fine if your donated sled was an alpine, could have the winch then too.
Rick

 

[Redneck in training]

http://thekneeslider.com/archives/2008/02/05/hydrostatic-2wd-motorcycle-raccoon-update/

Welcome to Hydraulic Innovations

Check those out or Google Hydrostatic motorcycle to give you some idea.
I think it would work for low speed and high traction. Look for used zero turn lawnmower for donor hydraulic parts. Also look what parts are in zero turn mowers to make it move.
In essence you need reversible variable delivery pump and simple hydraulic motor. All powered by an engine with speed governor.
I would say go for it. If you do post pics of the process. We love pictures.

 

[MikeD74T]

I've considered building a twin track sled from two junkers for grooming my personal trails. Hydrostatic would be good in that application for turning individual tracks under load & not needing more than about 15 mph. Could also power a hydraulic winch or grooming drag. Doubt it would be very practical for a general riding sled.
If you build anything please post, pass or fail. Sometimes more ultimately comes from failure than success. MikeD74t