As for heating the engine...there are many other ways. I guess you are using a starter box because of the engine you have...so you have battery power.

Cheap as chips way is to put a car headlamp bulb in a bean tin or similar that will fit over the head of the engine...of course be aware that the tin will get very hot.
A more professional looking thing can be bought it is called "RC Sure Start" it uses the same principle of the bulb to provide heat but is insulated.
Or there are the wrap around type of warmers that use the same technology as tyre warmers....I have one of these that are very well priced in the UK- http://www.modelsport.co.uk/index.ph...FQQXwwod0n4F5A