09-02-2019, 09:53 AM
Pretty much what Bob said.
A standard, unmodified 1929 engine with original crank probably won't go much over 4500 rpm without valve bounce and that would be a prudent place to stop accelerating. For a tuned engine with a sound original crank 6000 rpm was generally considered the limit; but those cranks are 90 years old now...
If you want to drive at -30C, the car is likely to cope with it better than the driver! Of course you will want anti-freeze in the radiator, unless you drain down as soon as the engine is stopped.
The main risk is oil flow from start-up and you need a multigrade engine oil grade which is thin enough to circulate well at those temperatures - forget about straight 30's and 40's. Give it a good, slow, gentle warm up before going out on the road. I'm not a fan of radiator muffs, but at that temp it may be worth considering; or slip the fan belt off. People often don't realise that coolant temperature and sump temperature are two entirely different things - your radiator may well be warm in half a mile but the sump oil is still frozen treacle. If this was a regular thing it might be worth considering ways to gently pre-warm the sump.
Keep in mind Austin Sevens don't have ideal brake distribution. It's possible you might lock up the rear wheels on ice and spin the car. Having said that, I've always found mine enjoyable to drive in snow.
If there is salt or other de-icing material on the road wash it off after using the car.
And wear some warm gloves!
A standard, unmodified 1929 engine with original crank probably won't go much over 4500 rpm without valve bounce and that would be a prudent place to stop accelerating. For a tuned engine with a sound original crank 6000 rpm was generally considered the limit; but those cranks are 90 years old now...
If you want to drive at -30C, the car is likely to cope with it better than the driver! Of course you will want anti-freeze in the radiator, unless you drain down as soon as the engine is stopped.
The main risk is oil flow from start-up and you need a multigrade engine oil grade which is thin enough to circulate well at those temperatures - forget about straight 30's and 40's. Give it a good, slow, gentle warm up before going out on the road. I'm not a fan of radiator muffs, but at that temp it may be worth considering; or slip the fan belt off. People often don't realise that coolant temperature and sump temperature are two entirely different things - your radiator may well be warm in half a mile but the sump oil is still frozen treacle. If this was a regular thing it might be worth considering ways to gently pre-warm the sump.
Keep in mind Austin Sevens don't have ideal brake distribution. It's possible you might lock up the rear wheels on ice and spin the car. Having said that, I've always found mine enjoyable to drive in snow.
If there is salt or other de-icing material on the road wash it off after using the car.
And wear some warm gloves!