I just inherited a retired snow trac from Search and Rescue

[Snowy Rivers]

Yard art is a good thing...
Just sometimes it can get a little too intense for the neighbors.

I had to clean up my left over goodies as my renter that lives downstairs started making a bit of noise....

I agree...Out in the brush the machine needs to be 100% .....Triple A is not much good.....

I played with VW stuff a little bit in high school
The advice offered is GOOD STUFF.....

 

[WardPilot]

Deep in research here. The input is great. Talking to a mechanic who says he can make what I’m interested in but want to know the flywheel specs. if I got his question right (heavy accent, but speaks perfect broken English), is it a 12 hole 200mm?

 

[Sno-Surfer]

Deep in research here. The input is great. Talking to a mechanic who says he can make what I’m interested in but want to know the flywheel specs. if I got his question right (heavy accent, but speaks perfect broken English), is it a 12 hole 200mm?

he is probably asking if its 12 volt (vs 6 volt). It matters to make sure you have the correct starter gear. I would reuse what you have as far as flywheel and starter combo. I forget the number of teeth between the 12 volt and 6 volt flywheel but it can be looked up and you can count yours to see what you have.

 

[WardPilot]

I’m getting closer - betting he‘s asking 12v and 200 mm clutch.

 

[luvthemvws]

He was asking about "12 volt". The engines newer than 1967 used a 130 tooth flywheel with a 200 millimeter clutch and an o-ring to seal it to the crankshaft. The older engines were "6 volt" with a 108 tooth flywheel and a 180mm clutch. These sealed to the crankshaft with a thin gasket. The 200mm clutch and the o-ring are a big improvement, but the "6 volt" transmission requires some grinding to accept the "12 volt" flywheel.
It is not difficult to grind open the transmission but BE CAREFUL! This creates magnesium dust and filings which are Explosively Flammable!! That's what incendiary bombs are made of!
From there, a different bushing to support the nose of the 12 volt starter shaft and you are home free. Or use a modern, self-supporting starter.
The 200mm clutch is a big improvement and there are many choices for heavy duty replacements. Something worthwhile in a vehicle that has to start out in soft snow.
If you rebuild an air cooled engine for the snow trac, be sure to install a "counterweighted crankshaft". Those stop the engine from pounding out their main bearings. That's what ruined countless numbers of stock VWs that were driven hard. And working hard at elevated rpm is what a snow trac is all about.

 

[WardPilot]

News flash. New Snow Trac Tires.

4.50-16 pneumatic tire for Bombardier Snow Coach etc...

Tires and wheels / rims for snow cats and snow grooming machines

www.alpineguidetire.com

News Flash. Alpine ordered snow trac tires last August (2021) Just went into production with availability in a few weeks (September 2022). Get you orders in now. Also get the high pressure tubes!

 

[Cidertom]

And from the peanut galley: Towards the end of production Aktiv made a few changes that helped the heat situation. The bottom pan had several largish (2"x 4") holes punched in it. I don't have over heating. I don't have bottom tin on the engine. I did this last year add an oil cooler, but that was to keep the oil at a more reasonable temperature. Also I eliminated the stock oil cooler as the termocouples I installed said #3 cylinder was running hotter than the others (now it doesn't).

When VW installed these engines in their vehicles, they used an open intake plenum around the top of the engine and sealed off the lower half. The "tin" is designed to route hot air towards the back of the (VW) vehicle. Where the air stream (under the vehicle) actually pulls it by venturi action reducing back pressure and keeping the air flow free. We in the ST don't have that. Those lovely drive chains all but eliminate the two plenum concept that VW envisioned. When the ST added the sealed intake horn that became the intake plenum that brought in cool outside air. That left the outflow plenum being the entire under hood area. But when all the tin is in place, it directs the air flow to the front, against the air flow from motion. That, and the earlier models had very limited outflow area, not much bigger than the inflow. That trapped hot air in the engine compartment. to combat this, Aktiv also added lovered vents under the windshield to reduce the heat trap that was near the variators.

I've run in -5-0-5 degree several times and the cylinder temp gauge say we be fine. I don't have a thermo damper. I do pay attention to make certain the cross tube is working (use a IR camera) when I do the yearly maintenance. I did install some small 12 volt fans under the windshield vent lovers, but these are more snow/ ice melting on the windshield than cooling.

just some thoughts. I know the loss of tin is heresy in the VW world, but remember we don't have vw's...

 

[nikos]

Wardpilot.
Wellcome to the SNOWTRAC World.

Get Start Reading and find ( taking notes and fotos) from the oldests threads in FF about ST4 .
We need more FOTOS from the engine, the sprockets, the condition of the Variator System, if something missing etc.
Also Inside the cabin, the dashboard tachometer ect, the deck and off cource the carbiratures.

Nikos

 

[JimVT]

News flash. New Snow Trac Tires.

4.50-16 pneumatic tire for Bombardier Snow Coach etc...

Tires and wheels / rims for snow cats and snow grooming machines

www.alpineguidetire.com

News Flash. Alpine ordered snow trac tires last August (2021) Just went into production with availability in a few weeks (September 2022). Get you orders in now. Also get the high pressure tubes!

are you switching over to this tire?

 

[WardPilot]

Update… bought new engine: vw type 1 1835cc dual port single carb, low/mild cam, 92mm bore, 90hp (image attached).
I found an image of a doghouse oil cooler mounted in the air intake assembly. Please share your thoughts about this application.
New tracks to be delivered in 10 days. While doing critical measurements found large gash in rear tire and it has a different tire on each side. Knowing the tracks will be off soon this is my chance to easily replace questionable tires. I have ordered two with high pressure tubes and am trying to find a local source for poly fill. If nothing local I can ship them to fallline.com for filling.
regarding photo requests: in addition to what I posted I just took an interior shot as of today (a lot has been done).
Additionally, I’m showing the dream dash I found online and am hunting for gauges accordingly.

 

[luvthemvws]

It looks like you are doing really well!
That engine should prove to be a real powerhouse!
I hope the builder used a "counterweighted crankshaft" and the thick wall version of the 92mm piston and cylinder set. (That version fits in the crankcase bore normally used for the 94mm cylinders.)
If so, you have an excellent foundation!
My only real concern is the carburetor and intake manifold in the photos. The carburetor itself is more than fine, but the intake and air cleaner are going to be it's downfall. The carburetor sits too high to allow an appropriate air cleaner (with warm air inlet provision) and still provide Snow Trac hood clearance.
But the biggest issue will be the intake manifold. That model has no provision for exhaust to heat the cross tube portion of it. An exhaust-heated intake is ESSENTIAL to good cold weather operation of a VW!
There is a vendor for Weber products called Redline. They offer the proper heated intake manifold for the VW. Their intake accepts the Progressive Weber carburetor. The Weber Progressive cannot equal the power potential of the carburetor in your photos, but it doesn't sit as high (remember, hood clearance), but the "good" heated intake and warm air inlet air cleaner will let it RUN CIRCLES AROUND the intake/carb in your photos!
Visit aircooled.net or the "sticky" under Performance and Racing in the Forums at thesamba.com that deals with "Making the Weber Progressive Work on a VW."
There is a contributor on there (John, from air-cooled.net) that explains exactly how to make the Progressive Weber work properly on a VW. Solid gold information, there.
The proper, heated intake and a header/muffler with the appropriate heat crossover plumbing (and the warm air inlet for the carburetor) and you will have a FINE running Snow Trac!

 

[Cidertom]

well, the oil cooler pix is mine. it really helped keep the oil temp where I liked it. No noticeable decrease in air flow. if you look at the stock oil cooler, the air passages are not great.. I have the hoses routed so they can stay attached when I take the intake horn off to access the variator and such.

 

[Cidertom]

My only real concern is the carburetor and intake manifold in the photos. The carburetor itself is more than fine, but the intake and air cleaner are going to be it's downfall. The carburetor sits too high to allow an appropriate air cleaner (with warm air inlet provision) and still provide Snow Trac hood clearance.
But the biggest issue will be the intake manifold. That model has no provision for exhaust to heat the cross tube portion of it. An exhaust-heated intake is ESSENTIAL to good cold weather operation of a VW!

I wish we had more hard data on these issues in the Snow Trac's. usually my underhood air temp is fairly warm even in cold use as it's getting all of the used cooling air. To the point that on shut down I can usually hear the fuel boiling in the carb if I've been running for a time *. I do check my crossover tube to make certain it isn't plugged though to keep the body warmer to retard ice formation on the venturi when I hit the jackpot of humidity and cold (fairly rare in reality) until the underhood temp is high enough to keep ice from forming. Again this is one of those differences from a VW. The VW is drawing in carb air from the cold side of the engine. In the ST we draw in carb air from the Hot side. I may need to invest in more thermocouples.

* that is why I added an electric priming pump in series with the stock fuel pump. That way I don't have to crank to refill the bowl.

 

[luvthemvws]

The very learned Cidertom makes good points.
I too have experienced fuel boiling in the carburetor bowl. My further testing showed that to be due to the "low vapor point" of the lousy crap they call "gasoline" these days. The modern, fuel injected engines can deal with that just fine. The older, carbureted engines struggle with that a great deal.
The problem for the opposed VW engine is the cross tube portion of the intake manifold. If the manifold is not thoroughly heated the fuel condenses onto the insides of the intake, before the fuel gets to the combustion chamber. This makes the fuel/air mixture too lean. To compensate, the driver has to engage the choke and/or jet the carburetor much richer than is ideal. There goes your fuel economy. And worse, sooner or later that condensed fuel will dribble it's way into the combustion chamber and now the engine sputters and gags on all the raw fuel! Worse economy! No power! Rough running! (If it keeps running at all...)
Heat that intake! Provide hot air to the air cleaner snorkel! Use high octane, Non Alcohol Blend Fuel!!
Your air cooled VW will thank you for it!

 

[WardPilot]

Excellent input. The engine photo is from the shop that’s building mine. Mine has a estimated delivery before thanksgiving. I will have the builder make modifications regarding the intake and was already researching hood bulge per ‘Luvthemvws’ thoughts.
the crankshaft is spec’s as counterweight.
the only fuel I run in all my vehicles is ethanol free.

 

[nikos]

WardPilot
As we talking about the rubber tracks, i think when its necessary to replace the belts, you have also to change the derection of the custom grousers, because in the fotos,
the V Shape, the pattern of them it is not in the right direction. Its opposite.

Nikos

 

[nikos]

The V Shape, the Pattern of the grousers in the rear tyre in the ST4 and in the Tractor with the rubber belts.
The defence.
Nikos

 

[WardPilot]

??????????????????????????? So these are backwards?

 

[DAVENET]

If you have track spin, the snow under the track is being forced INTO the center of the wedge catching it and filling it. Flipping the other direction, the snow would be pushed from the center to the outsides of the track if spun or in a tight turn.

 

[nikos]

View attachment 154372
??????????????????????????? So these are backwards?

Exactly.
Ed you can see the difference of the V Shape on the front Tractor Tyres.
When you decide to broke the track, just to replace the two rubber bands, then its easy to fix them from the beginning. Ok

Nikos

 

[luvthemvws]

I think Davenet is on the right track. If the tracks are turned around the Snow Trac will tend to dig itself into a hole. The way they are now, scooping the snow towards the center of the track, will tend to keep the Snow Trac on top.

 

[JimVT]

some have reversed the tracks because of excessive traction causing them to detrack. those larger alpine tires will shorten your belts.

 

[WardPilot]

First let me say that I’m buying the first round (at least) at the next pacific nw gathering. Second, your powers of observation as a group, let alone the tracks installed backwards, are wonderful, if not amazing. It makes me feel great to have this support. You’re rock stars! every idea leads to a new idea! Thanks. Ed Ward Snohomish Wa. (Formerly: Goteberg, Sverige) Tack så mycket!

 

[Cidertom]

Couple more inputs on your rebuild: Stepping outside the normal power for an ST, consider the next step as well. Throttle body EFI is available for the vw engine. The reliability of these has improved to the point that they are as reliable as the carbs. And given the sorry state of fuel quality, perhaps more so.. This would delete the need for a bump on your hood.

The second thing I would do is at least pull the track drive sprockets, an get a hard look at the axle tubes, bearings. look for stress cracks in the tubes and slop in the bearings. In my opinion the drive axle tubes are one of the weak points in this system They carry a heck of an overhung load, and increased HP is going to make the issue worse. I found a couple of cracks with UV dye. And had them welded.

CT

 

[JimVT]

Couple more inputs on your rebuild: Stepping outside the normal power for an ST, consider the next step as well. Throttle body EFI is available for the vw engine. The reliability of these has improved to the point that they are as reliable as the carbs. And given the sorry state of fuel quality, perhaps more so.. This would delete the need for a bump on your hood.

The second thing I would do is at least pull the track drive sprockets, an get a hard look at the axle tubes, bearings. look for stress cracks in the tubes and slop in the bearings. In my opinion the drive axle tubes are one of the weak points in this system They carry a heck of an overhung load, and increased HP is going to make the issue worse. I found a couple of cracks with UV dye. And had them welded.

CT

axle tube was already damaged on this one to what extent i don't know.

 

[WardPilot]

1. yes. Goteberg is Swedish for Gothenburg Sweden (hence a passion for snow trac)
2. Who’s got technical specs for a 15 tooth driver? I want to make them.
3. “JimVT”, are you getting my emails. Any idea if SAR attempted to repair the axle tube?
4. Any tips on how to reinforce the axle tubes beyond basic welding of cracks?
5. Anyone know how AlaskaJT’s 18 tooth drive panned out- found nothing since 2017.
6. mechanic says I won’t need hood bump (yeah). Has a low profile air filter application for me.
7. hate to compromise the clean aesthetic, but seriously want to get the heat elements out of the engine compartment - looking to go the direction of this attached photo. Input welcome and appreciated.
8. ordered louvered vent to match style, same size and profile, to be placed between hood and windshield to both vent heat from engine and add defrost element to windshield.

 

[Cidertom]

since the pitch of the chain is the same as SAE 80 you could use that info or as others have done turn the existing teeth off to be a hub and weld in a new sprocket. Please note that while you could use a SAE sprocket, you cannot use a SAE 80 chain. it is too narrow for the driven sprocket. While it would be a pain, I'd suggest a winter of using the stock sprocket first and experience the race car like suspension of the ST. Unless the snow is great, I rarely get into 4th gear.

 

[redsqwrl]

1. yes. Goteberg is Swedish for Gothenburg Sweden (hence a passion for snow trac)
2. Who’s got technical specs for a 15 tooth driver? I want to make them.
3. “JimVT”, are you getting my emails. Any idea if SAR attempted to repair the axle tube?
4. Any tips on how to reinforce the axle tubes beyond basic welding of cracks?
5. Anyone know how AlaskaJT’s 18 tooth drive panned out- found nothing since 2017.
6. mechanic says I won’t need hood bump (yeah). Has a low profile air filter application for me.
7. hate to compromise the clean aesthetic, but seriously want to get the heat elements out of the engine compartment - looking to go the direction of this attached photo. Input welcome and appreciated.
8. ordered louvered vent to match style, same size and profile, to be placed between hood and windshield to both vent heat from engine and add defrost element to windshield.

2. I make and supply sprockets to any tooth count you would like. I have 15 tooth in stock.
4. to some extent the tubes are indestructible unless you are pushing the machine with unecessary force ( its not a tank)
6. agree run a hose to a filter canister. consider ducting selectable warm air to it.
7. your rig has the heat baffle keep it. If you have a dog house oil cooler you will need to carefully fit the air horn back on. I suspect it did not fit all along and the air horn was drawing in underhood air as opposed to fresh air.

Random bits of noise:

• I think if the swedes had the 1.8L EJ pushrod subaru engine back in the day they would have used it. it is a delightful upgrade.
• 1st gear is a placement gear. back up to trailer, pull ahead with great control. breaking loads free ( think tractor)
• getting ratios altered to closer ratios is great, but get shifting out of your vocabulary. these rigs are snow trac-tors sure they can be shifted but you will quickly find that carrying a gear is more desirable than rocking your passengers and cargo around constantly shifting,
• put your effort in a balanced motor. in my opinion this the single best upgrade Not higher hp, just more useable RPM
• read lyndons variator post multiple times with only a beverage in your hands. after you figure out the intent of the process practice on making adjustments after you rule out every possible possibility of why it won't turn.
• I have 4 snow tracs and each one is unique onto itself. I piss pound one without regard, and have a liquid cooled one from 58 that will out steer any of the other three.
• each part of the snow trac has a cause and effect with the remaining parts. foam fill the tires and you will notice the sluggish steering due the herringbone grousers
• snow tracs are designed to ride proud or high on the small boggies. if those springs are sacked or square tubs slightly bent the steering and nimbleness goes out the door.
• this thread has the best advice from experienced operators. snow trac in proper hands are great nimble rigs that can handle the most varied terrains they are the closest thing to a perfect snow cat. smooth, easy to drive, light, easy to trailer, multiple seating, quiet, sip fuel, pull a load.

 

[Cidertom]

#4 exception : Not forgiving of stumps, ditches you don't see.

 

[WardPilot]

Dear “RedSquirrel”,
I wish to acquire the 15 tooth sprockets you have.
send me an invoice: wardpilot@yahoo.com

To Everyone following this, here’s a status update - focus has been on accumulating everything upfront before jumping in with both feet to begin this rebuild marathon.
Prepping my shop was first with lots of rearranging and have installed ceiling hoist (images below), gotten jacks & roller Dollie’s…
1. Engine arrives this week. Image below is mine. Based on specs, it’s a perfect, albeit tight fit.
2. tires and tubes are in
3. new steering wheel (original made getting in a bit too tight). For you purists: I can go original when I lose some weight.
4. track belts have arrived
5. variator belt has arrived
6. Hood lovers are in for windshield defrost and engine heat outlet (they not exactly what I hoped for and will likely make a replacement mysel).
7. Plan on keeping the herringbone grousers “backwards” based on the detracting history and images relating to snow trac that my research uncovered. See below.
8. current mindset is to wait indefinitely on having tires poly filled. Something I can always do later.