I had the 45DCOE freeze up on mine. Going through Blayney (one of the coldest places anywhere) onto Bathurst from Cowra probably about 7:30ish in the morning.

thought was bit funny going through Blayney and then in Bathurst I had to stop for traffic and just kept the revs up and wouldnt drop, didnt make it undrivable but changing gears and trying to stop were not the greatest.

pulled into the servo and saw ice on the webber and moved it round a bit filled up (and i assume heat from engine filled bay and helped melt it as well) went fine after that

It would have been woolies Vortex (so yeah Shell 98). Froze up because it was cold though, I dont blame the petrol

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I find that a blip will break the ice. The ice is stronger than the return spring. The cable is stronger than the ice.

Dr Mini, Saturday morning was the coldest morning this year in a lot of areas. I don't think the petrol was the main cause of your carby ice.

With frozen carbies they don't all just freeze the throttle. They often work properly except for the big lump of ice blocking the venturi!
SU's will sometimes freeze the piston. If the throttle spindles are worn it is more likely that the throttle sticks.

pardon my ignorance, but how do many UK drivers go with much colder weather?

I can remember my old man and me once sliding across roads on black ice back home as a kid, but can't remember him ever mentioning carby ice as a problem (he was a car mechanic and worked on many Minis in the 70's)

just wondered

UK Minis have carb heaters in some cases (Canada spec Minis all did), and heated aftermarket manifolds with water actually connected (except with twin carbs).
Carb icing really only happens during long periods at fairly high speed with constant part throttle.
eg Highway/motorway.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

ha ha, fair enough. My uncle freaked that I once rove my old Mini to Sydney & back every day from the Gong for work. He thought I'd be staying over for the week.

I guess a lot of UK Minis aren't driven that far out of town. A trip from Liverpool to Manchester was an event for us as kids!

Constant throttle I guess would be the key as well as the right conditions/humidity etc for ice formation.

I had no Carbie icing this day but the car had thick ice build up right across its nose, bonnet and windscreen on a trip over the blue mountains a couple of years ago.

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68 Morris Cooper S Mk1 (*ex 78 1275 LS 4th last built, 70 Morris 1500 OHC & 70 MiniMatic)

Carb's icing up in Aus ? we don't get that problem here in NZ and its way colder.

Is it because the card is not directly above the exhaust any more being a Weber

Probably more to do with atmospheric conditions than fuel. All fuels are hydroscopic, this is why good service stations check for water every month (or fortnight) if you were in Adelaide I would give you a bit of water finding paste to check the fuel in the car. I'm sure you can buy it somewhere.

Else a combination of high humidity (fog) and the right temp and it will ice, especially in an area where the air pressure and air speed changes rapidly (such as a Venturi)

Solution? Check for water in the fuel, or heat the manifold. (is there a gasket that isolates the heat from the head from the manifold?)

On mine, the Dellorto carb is bolted to the manifold with a normal gasket (not those O-ring things that leak- Dellortos don't need em for road use).
I have no heatshield under the carb (unlike with an SU).
But at speed there is little heat radiation up from the LCB, due to all the cold air rushing in the front and then down the back of the motor.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Original design had the carb at the front of the car, but they moved it to the rear simply to prevent carb icing. The final design for the single SU had the inlet for the air filter casing pointed towards the exhaust manifold. The owners manual says to rotate the air filter casing to point the inlet right at the exhaust in winter and away from it in summer.

Other makes have a shroud around the exhaust manifold with a gate that you manually switch over in winter.

cheers
michael

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the world is a book, and those who do not travel read only a page
66 Mini Minor sponsored by http://www.lifeonthehedge.com.au/ The Dog Harness Specialists
It was a pleasure ausmini. I'll miss all you misfits and reprobates

We can and do get the right conditions for Carby Icing in Oz...

in the olden days...we used to partially or fully blank the front grill off...

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"Show me the Mini!"

On the other end of the scale early european cars were prone to vapourising the fuel.

My father had a series of Peugeots - a couple of 203s, a couple of 403s and later a 404. In the 203 and the 403, the fuel line wa routed close to the block and the manifolds so that the fuel was partially preheated to avaoid carby icing.

It was a nightmare in the hot Australian summers and the fuel lines had to be routed away from the hot parts to avoid fuel vaporisation. Cook and Saville on Parramatta road at Flemington were the main dealer /workshop for these cars and did a roaring trade fixing the fuel line routing problem.

Having said that we didn't have the freeways we have now and you couldn't sit on 110km at a constant throttle for extended periods of time.

Mike

Ice is formed in venturi-type and slide-type carburettors in ambient air temperatures ranging from about –10 °C to +30 °C if refrigeration and adiabatic cooling within the airways are sufficient to lower the air/fuel mixture temperature — and consequently the metal of the carburettor — below the freezing point. There must also be sufficient moisture in the air, but this need not be visible moisture. Ice may form at the fuel inlet, around the valve or slide, in the venturi and in curved passages, choking off the engine's air supply. If icing continues, this will cause the engine to stop.

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1970 Mk 2 Cooper S

Woolies fuel is Caltex not Shell, at least that is how it is in Qld.

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1964 998cc Cooper
1971 Mini K x 2
1972 Clubman GT

Woolies is Caltex here in Sydney too!?

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