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Thu Aug 10, 2017 7:17 pm

I have a 1959 Kristi snowcat that will be in service during the winters in North Idaho with an elevation of 2800. Not super cold but we get some freezing. I am rebuilding the motor:
1600cc DP
forged Mahle pistons balanced
30/31 carb
Engle 90 cam
Doghouse cooler/fan

Now due to the SLOW speed of this machine will I have oil cooling issues?
Will stock piston/cylinder clearances need to be a little bigger?

Thanks, vwdon

Thu Aug 10, 2017 11:34 pm

I had to do a little research on what a Kristi snow cat was. I don't think you are going to have any problems whatsoever in fact it will probaby run a little cooler with the dog house.

I also doubt you need to worry about piston/cyl clearances with a stock motor with a mild cam. I would just build it using factory clearances.

The little extra punch might get you close to 30mph!

Fri Aug 11, 2017 4:40 am

Winter operation of air cooled engines normally does not pose an overheating problem as long as the cooling system intake air is sufficiently separated from the discharge air. Overheating of VW engines happens mostly on hot summer days running above hot pavement with the engine breathing in everyone else's hot engine cooling air and exhaust. You will see none of that ever!

I would suggest that quite the opposite will be the problem. Make sure you have a fully functional thermostat with all the flaps, linkage and sled tins. I tried to run my sand rail in the winter without and it ran like absolute crap! I could not get it warm enough to run without the choke on unless I partially blocked off the cooling fan. Then I was constantly having to adjust the amount I blocked it and the engine was always running too warm or too cold.

Fri Aug 11, 2017 6:09 am

Your oil (and engine) cooling will be more dictated by engine speed than oil cooler size or design. You CAN'T lug your engine around at 1500-2000 rpm all day and expect it to live. You need to keep the engine in the 2500-3000 rpm range I've worked on enough industrial engines in crop sprayers and Zambonis to see what people do to them, usually they go in the bin after we pull the tin and accessories off because they have been so badly overheated from lugging them around, there is nothing left to salvage.

Keep your engine speed up and you'll be fine.

brad

Sat Aug 12, 2017 7:30 am

Thermostat and flaps for proper engine/oil temp. As mentioned keep the RPM up.

Sat Aug 12, 2017 9:19 am

Sounds great. Not as complicated as I was anticipating.
Thanks to all.
Vwdon

Sat Aug 12, 2017 9:56 am

low rpm needs big oil pump.and thin oil. you could also duct some of the hot air back to the fan for faster warm up then close it off.A thermostat could be used for this or just a pull lever. I would only use synthetic oil.

Sat Aug 12, 2017 2:16 pm

I plan on running 3000 rpm to 3500 rpm. Having 8 gears to select from I should be able to make that work. I was thinking 10-30 oil or 0-20 if I can get it in swepco brand d/t the Zinc

Sat Aug 12, 2017 6:33 pm

quaker state high millage semi synthetic with green cap has zinc, I use it in the 5-20 5 quart jug at wally world for about $15.00, it no longer list it as having zinc on the label since they changed all thier labeling earlyer this year, I contacted them and the oil still has the zinc and they were not aware it was no longer labeled as such. Ive used it in the kids cars & the wifed honda for many years and started using it in my bug about 2.5 years ago since it's $12 cheeper than the ful syn I was using :shock: yup Im cheep and the car is too, and lotsa fun miles on it.