Winter fun - Project “Freedom” 440cc 2 Stroke 1054 Snowmotractor

[Pullstart 59,859]

3 hours ago, 8ntruck said:

I wonder if swapping from the 3 speed to a hydro transmission would get you more speed?  The hydro would give you a 'low gear' to start up with, then allow you a 'higher gear' for more speed while still keeping engine rpms in the power band.

 

Then again, pump driving speed limitations would probably be a limiting factor....

I’ve got some… I wouldn’t mind double overdriving one to see what happens!

[wallfish 15,959]

You should be able to get that up to 40 mph or more with the manual trans. Doubtful the hydro could handle that. Although it would definitely be interesting to see what one could handle!

Saltywright Russ had a hot rod tractor I built years ago and he GPS'd it at 37 and it still had more to go. And yes, He was almost 90 years old too! It was a bit on the dangerous side going that fast for what it was with being built from mostly tractor parts. You have a good beefy front end and a much bigger motor than a 12 hp Kohler plus a 2 stroke goes much higher RPM too.

[Pullstart 59,859]

3 minutes ago, wallfish said:

You should be able to get that up to 40 mph or more with the manual trans. Doubtful the hydro could handle that. Although it would definitely be interesting to see what one could handle!

Saltywright Russ had a hot rod tractor I built years ago and he GPS'd it at 37 and it still had more to go. And yes, He was almost 90 years old too! It was a bit on the dangerous side going that fast for what it was with being built from mostly tractor parts. You have a good beefy front end and a much bigger motor than a 12 hp Kohler plus a 2 stroke goes much higher RPM too.

I just have zero low end torque until I wind it way up.  If it slows at all, it will bog down and stall hard.  But a high rpm 2nd gear launch lifts the front end a safe 4-6”!

[wallfish 15,959]

5 minutes ago, Pullstart said:

I just have zero low end torque until I wind it way up.  If it slows at all, it will bog down and stall hard.  But a high rpm 2nd gear launch lifts the front end a safe 4-6”!

That's why it needs to use that variable pulley. Does the snowmobile still have the driven pulley in the trans? Is that variable too?

[Pullstart 59,859]

5 minutes ago, wallfish said:

That's why it needs to use that variable pulley. Does the snowmobile still have the driven pulley in the trans? Is that variable too?

It does, but I ran out of room for the time being.  

[wallfish 15,959]

15 minutes ago, Pullstart said:

It does, but I ran out of room for the time being.  

Room to mount it? Or it's buried?

If you can get it, bring it to the show. Maybe we can pitstop work on it Wed in the hotel parking lot! LoL  Or at least come up with a plan to try and make it to work.

[8ntruck 6,419]

As I suggested earlier - add a jackshaft for the snowmobile driven pulley?  Would that be an option to make room?

[Pullstart 59,859]

Not in the next couple weeks, but maybe before snow flies again..

[953 nut 51,940]

12 hours ago, Pullstart said:

I’ve got some… I wouldn’t mind double overdriving one to see what happens!

           My guess is that the pump impeller would cavitate at substantially higher input RPMs.         Of course we don't yet know what "substantially higher" is until we get there.    Once you start hearing the popping and the heat rises considerably you have defined "substantially higher input RPMs"      

[8ntruck 6,419]

 You are probably right - the pump would start to cavitate at some point.  Doubling the pump speed would come close to doubling the flow.  At some point, the porting in the pump won't support the increased flow, which will cause cavitation.  Cavitation will do bad things to a swash plate.

[Wild Bill 633 770]

I am in the process of building a custom lowered WH tractor based on early 1960's sheet metal. The engineering & design phase is complete and starting the fabrication phase. The power will be provided by an altered 25HP Kohler Command with a Comet CVT clutch. The CVT driver pulley will be mounted on the engine crankshaft and the CVT driven pulley will be mounted on a jack shaft under the battery. A V-belt driver pulley will also be mounted to the jack shaft with the driven pulley mounted on the input shaft of an 8-speed transaxle. The calculated max. CVT ratio is 0.53:1 with a 1:1 V-belt ratio.

FYI, a "cast iron" V-belt pulley needs to be balanced at speeds >5000 Ft/Min and max. speed is 6500 Ft/Min. The max. speed of a "steel" pulley is 10,000 Ft/Min. If you spin them faster, you run the risk of a pulley exploding.

Edited June 9, 2022 by Bill633

[Pullstart 59,859]

3 minutes ago, Bill633 said:

I am in the process of building a custom lowered WH tractor based on early 1960's sheet metal. The engineering & design phase is complete and starting the fabrication phase. The power will be provided by an altered 25HP Kohler Command with a Comet CVT clutch. The CVT driver pulley will be mounted on the engine crankshaft with the CVT driven pulley will be mounted on a jack shaft under the battery. A V-belt driver pulley will also be mounted to the jack shaft with the driven pulley mounted on an 8-speed transaxle. The calculated max. CVT ratio is 0.53:1 with a 1:1 V-belt ratio.

FYI, a "cast iron" V-belt pulley needs to be balanced at speeds >5000 FPM and max. speed is 6500 FPM. The max. speed of a "steel" pulley is 10,000 FPM.

Cool stuff to know!

[Handy Don 10,658]

17 hours ago, 8ntruck said:

Cavitation will do bad things to a swash plate

And surprisingly fast. Ship propeller designers have learned this painfully.

[Pullstart 59,859]

I was looking for a second spare GT14 wheel.  I found where the bunch of spare parts came with Freedom and proved to myself I only had one spare wide 15” wheel 

 

https://www.wheelhorseforum.com/topic/86662-three-peat-hat-trick-big-wheel-trio-1054/?tab=comments#comment-879400

[Pullstart 59,859]

 

[8ntruck 6,419]

On 6/7/2022 at 9:09 PM, Pullstart said:

Not in the next couple weeks, but maybe before snow flies again..

Ya know, weather bug is saying that snow will be flying in the next few days......

[Pullstart 59,859]

1 minute ago, 8ntruck said:

Ya know, weather bug is saying that snow will be flying in the next few days......

well.. we need an accumulation base anyway!

[tractorchick 399]

On 2/6/2022 at 9:23 PM, Pullstart said:

I hope it will be this much fun!

 

 

 

Y'all notherneners have all the fun! 

[Pullstart 59,859]

 

[Pullstart 59,859]

I’ve been fretting the fact that the steering shaft is about 12” from the center of the crank, the precise location the secondary clutch needs to be hiding in.  Well, I had an aha! moment tonight.  The secondary can be ABOVE the shaft!

 

 

[Pullstart 59,859]

Wild Thing!  You make my heart sing!

 

I love Polaris powered Snowmotractors!  The secondary clutch rides on a 1” keyed shaft.  How convenient!

 

 

[Pullstart 59,859]

Something tells me I’ll need to slide the engine to the passenger side a bit.  I’ve got tools for that!

 

 

[Achto 26,611]

I think you're going to be much happier with this set up when you're done.

[Pullstart 59,859]

12 minutes ago, Achto said:

I think you're going to be much happier with this set up when you're done.

Me too!  Now I need an Engineer that is good at matching math to help me figure the transmission drive pulley size.  @8ntruck?  You out there Bill?

 

Me thinks a 1:1 drive on the transmission would be a good start.  Something like a 6” pulley on the secondary clutch shaft and run the stock 6-1/4” pulley on the transmission for now.  The primary/secondary will be a huge adder to the system, getting low end rotation speeds.  I’ll think hypothetically here and assume a 4” engine pulley driving a 10.5” secondary pulley.  It could vary to a 7” pulley and we’ll assume a 6” pulley once the secondary opens fully.  Max engine speed is 8,000 rpm but we’ll assume a stall speed on the primary around 3,000 for acceleration purpose.  Quoting @MikesRJ here are the transmission ratios (using HI only) and the tire diameter is 30”.

Gear...... HI Ratio ....... LO Ratio

1 ........... 66.8:1 ........... 267.2:1 

2 ........... 42.4:1 ........... 169.6:1

3 ........... 24.6:1 ........... 98.4:1

R ........... 51.5:1 ........... 306.0:1

[Pullstart 59,859]

Never mind Bill, my German kid Jil says 7,000 ducks.  We’re all good!