Drive it cold or let her warm up?

[Will]

The difference between a carb an EFI with respect to cold is that the fuel in a carb is mixed with the air 8" away from the intake valve, and into fairly large droplets since only atmospheric pressure is available to break it up. The fuel doesn't want to burn because it's cold, and it's in big cold chunks. The factory has stoves that run from the exhaust manifolds to heat the intake air to quicken the heating of the system. It's a surface area problem and the droplets need a higher airspeed to break them up and a harder pull, hence the choke.

Carbs really suck in the cold. They are bad everywhere else too, but they really show their ass in the cold. With fuel injection the manifold is dry, no fuel to think about. Plus, the injection is at 40psi more than atmosphere--55psi compared to 14psi--plus it is sprayed right at the back of the valve and doesn't have 8" of travel to cool it back into liquid.

A fuel injected engine--just drive after it starts. Drive easy for 5 minutes so you don't break the oil-pump drive shaft.

A carb engine--you learn to milk it along so it warms up. I would not let it sit and idle. All that raw gas is washing the oil off the cylinder walls. It's full of cold gas that isn't being burned when it's sitting there at a cold idle. It's a big factor in why new engines last 400,000 and old engines were being traded or given to the teenagers at 60,000.

 

[tmcalavy]

Ahh...ain't it great to have a choice? Warm it up or get in and go. After about 50 that choice disappears...my truck warms up faster nowadays than I do. Takes me about that long to check all the parts and their condition, then it's off to the coffee station...anyone seen my smokes?

 

[85_Ranger4x4]

The ones I have with a manual choke, I pull the choke half on either pull or push the starter linkage and rarely do they go over more than once. Let it run on half choke until it starts losing power and then open the choke up. And then they run until either you shut them off or run them out of gas.

I look forward to seeing how current EFI systems are doing 50-60 years down the road (I doubt I will be around to see them at 70 years of age like my tractors)

A decently tuned carb on a vehicle isn't that much of a hinderance either IMO. I am plenty happy with how my Edelbrock runs on my Ranger. Yeah you can't use the secondaries until the choke is open... but then you shouldn't be using them until the thing is good and warm either. I also think an electric fuel pump is far superior to a engine driven mechanical, you always have fuel right there to the carb without cranking the engine.

I know they are not as perfect as EFI but they are stupid simple and work.