Q: How do you keep an engine from cracking in cold weather without a radiator?

Hi there. The best thing to do is remove the radiator cap to the radiator and try to untwist the lower radiator hose if you can. If you cannot untwist the hose and the coolant is full or if there is water in the engine and not coolant, then as long as the radiator cap is off then if the coolant or water was to freeze, then the water will come out of the radiator and not crack the block. Coolant with a full strength will hold up to (-75 F degrees). If there is water in the engine, I recommend draining some of the coolant to keep the engine freeze plugs from coming out overnight. Freeze plugs (casting or core plugs) are designed to come out in the event of the coolant or water freezing in the engine block preventing the block or heads from cracking as the water turns into ice. If you need further assistance with your cooling system, then seek out a professional, such as one from Your Mechanic, to help you.