Would this be possible

Yeah, an engine block is not really intended for cooking. But I guess you can do it if you have to. Much easier to buy a cheap mickey-wave, or use the one in the flyin' hook. I just bought a lunchbox cooker from Global Trucker and I'm learning to use it. Seems like it's going to be pretty easy. Good Luck!

 

I don't know if this has ever been done in a Truck, but I have an Uncle that use to work on a farm in Arizona and he brought his lunch from home and everyday he would stop plowing and put he lunch on the exh. manifold. Then get back in the cab of the tractor go down the field and back then take the food off and it would be nice and hot.

I'm sure if it can be done on a farm tractor it can been done on a Truck.

 

In my research on Schneider (and this may be true for the other huge companies) you can't use inverters to run microwaves (no mods to the trucks as they are all considered to be potential "slip seats.") I'm sure you can use a lunchbox cooker though.