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TR2/3/3A Winter driving question

2liter4cyl

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What is the proper weight of oil in the SU dashpots? Every thing I've ever seen says 20 wt. Yesterday I went to my shop to adjust the choke . With the filters off, I tried to raise the piston. Being 25F in January, it acted frozen going up or down. I really could not raise it with just one finger. Would 5W20 work in cold weather, or ATF? 50 years ago, in Iowa, my '59 was my only car, and it barely ran in cold weather. No wonder! Le
 
After some experimentation, straight 20 weight motor oil is what I use. According to "Practical Hints", 20W should be appropriate down to 10F. They recommend 10W below that.

I'm wondering if perhaps you have some other problem, especially since you say they would not go down either. There is a check valve that should let them fall fairly quickly on their own, even with heavy oil. What happens if you remove the plunger?
 
From my own experience, having driven my TR3 for ten years winter and summer in Northern New England, I can only say that dashpot oil viscosity was never a consideration. We used motor oil from dregs of whatever viscosity was available without issue.
Tom
 
I drove my '64 TR4 in the winters of 64-65, 65-66, 66-67 and the only problem was it had terrible traction in snow and on ice so I did not drive it a lot. I did find that folding a wool Army blanked in 1/4s and laying it on the top bows before installing the canvas helped the car stay toasty warm in the worst weather. I then had a '67 GT6 and drove that during the winter of 67-68 a couple times but that was far worse in snow and on ice than the TR4 was. I even tried those tire chains that had bars on the cross links. All that did was chew up the car body behind the doors. That led to repairing the body and painting a 2 year old car with less than 50,000 miles.
After those experiments I believe the best place for my LBC's is staying in the garage during the winter.
 
I had my first TR3 in Colorado where I drove it as my only transportation . I never changed the dash pot oil from summer to winter. Suspect I was like Tom and used what I had, which was likely 30 wt..
As to the cars performance in snow , I put aggressive snow tires on the car and kept a light foot on the gas pedal and that car was great in the snow. Never did put chains on even though I did carry them. And no I did not sit at home when it was snowing. However I never had to deal with the glare ice found back east.
Charley
 
I used to use a half can of starter fluid to get my bugeye running in those cold New England winters. Maybe if I had only used a thinner dashpot oil. :jester:

OK, I admit it. I carried a can of the stuff in the boot. Thought everybody did. Tom
 
I ran many cars with SU carbs year round, never changed the dash pot oil in winter. The solid axle TR4A I had started pretty easily even when temps were below zero, Fahrenheit, ran well in the cold, and did pretty well in the snow. Would change to 10w-40 in the winter (rather than 20w-50) and richen the mixture a couple flats for better winter running and faster warm up. My 1098cc Sprite was always a little cold blooded in extreme cold, and wouldn't fully warm up and run well until I blocked the radiator partially with a piece of cardboard.
 
Thanks to all on oil weight used. Guess I never had filters off in cold weather. With engine running, vacuum lift works fine! Thinking about it, 20" of vacuum on that big a piston works. Le
 
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