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Snotrac advice needed

mbsieg

mbsieg

awful member
PLATINUM FF Supporter
I pulled the engine out of the ST4 last night, clean up, maintenance, ect. Looking for advice on power in the snotrac. How do they perform at 8-10k elevation? It has the stock 1600 single port in it. Should I hop up the power while the engine is removed? If so what do you recommend? Any other preventive maintenance recommended while it is out? Thanks in advance.
 

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More photos please.

No advice to offer as mine was operated at >1000' above sea level
 
A couple more photos just for Bob.
 

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At altitude my chart says you will loose 20-25% of the 54 hp you have on tap.
Mine is a single port 1,600 and at those power losses in steep terrain I am sure you will notice.
If you running light load maybe ok. Load her up to max and maybe not so much unless you like 1st gear a lot.
If your not doing a lot of steep climbing you would probably be fine.

btw the single part has more bottom end torque. That said the dual ports has more up top.. maybe 65hp..

My two cents, Kirk
 
There are inherent limitations to a Snowtrac that make power increases only beneficial to a point.
The layout of the engine compartment pretty much limits you to a single, center mount carburetor. So, a Zenith or a progressive Weber are your most available options. Either of those will require LOTS of intake manifold heat and a warm air inlet for the air cleaner. Probable custom fabrication there cause no one manufactures an appropriate air cleaner.
More displacement will quickly get you more power, but the single carburetor will somewhat limit your rpm range. You'll find that even a nice-running 1776 or 1835cc engine will make 1st and 2nd gear almost useless because they are so slow for the power you have.
Build one of those engines with a low rpm/torque cam, pretty substantial compression (because the air is thin at elevation, and the VW is a pretty low compression engine in stock form), and USE A COUNTERWEIGHTED CRANKSHAFT! (Because you'll actually be using the engine's power potential for more of the time and a non-counterweighted crank will beat the main bearings out of it quickly in that scenario.)
Now, you'll want to change the gearing in the transaxle AND the sprockets. Because changing the sprockets gives you more speed (which your newfound power is capable of) but magnifies the jump between gears (which is already too big for deep snow use).
Project Creep will now have set in pretty severely, so you need to define your goal and budget priorities and STICK WITH THEM.
 
My $0.02. I run out of traction before I run out of HP normally. One time on Mt Hood, I was losing the hp race as I was trying to keep the tracks from spinning and digging a hole in the haul road. Reality: I had lost traction and that was the end. I needed the track speed to let them self clean the slop I was in, but that only dug a deeper hole....... High altitude yes you lose hp.
 
Well, the Autostick actually HAS a mechanical clutch (the small, 180mm one) in addition to a torque converter.
The torque converter would be a godsend to the driveline, but the mechanical clutch would give up under sustained load.
The Type 3 or Bus full automatic would be a better match, but has no way to attach the variator.
I am adapting the Autostick converter and bell housing to my Kristi, and eliminating the clutch, but that driveline is not adaptable to the Snowtrac.
 
PJL said:
I wondered that too. Not a Snow Trac guy. But would a fuel injected engine with an auto transmission work?
Click to expand...
In the Mexican Bug production the later versions of the engine had electronic fuel injection, and altitude compensation as well.
Once in a while I went on the hunt for one, but found little out here. Maybe that has changed, not sure.
I like your idea a lot!!! (y)
 
While the engine is out tear the variator assembly down to the vertical shafts. Inspect and repair as required. inspect the transmission input seal and the output seals for leakage. inspect the drive chains.
 
Yes, the Mexibeetle EFI would be nice for driveability and altitude compensation but brings a couple of packaging issues as well. The low hood of the Snowtrac really throws a monkey wrench into things.
If a person spent the same amount of time and effort into a carburetor system (as adapting and dialing in the efi) the carbureted engine would run nearly as well and be infinitely more serviceable in the boondocks.
To my mind it seems more pragmatic to build a simple, carbureted, 1776/1835 and possibly change ring & pinion gears to the 4.12 or 3.88 ratio and just enjoy the Snowtrac for its simplicity. You'll go broke and crazy spending all the time and effort to make the machine "perfect" and "all-conquering".
 
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