I have an old Mechanix Illustrated magazine which dates back to the
1950's.What it is, way back then the U.S.Army handed over a 1957
Chevrolet pickup truck to a guy in Motor Pool.They told him to make the
truck run on ammonia gas.At first he experimented with a lawnmower
engine.He got it running on ammonia gas, then he started working on the
truck.He mounted one or two tanks of ammonia gas which he had insulated
and routed the exhaust pipe to keep the ammonia tanks warm in the bed of
the truck and he fixed up a pipe from the ammonia tanks to the
carburetor.He had to start the engine running on gasoline, then he
switched over to the ammonia and the truck ran, but not with as much
power as gasoline.

The idea was, the U.S.Army could use small nuke plants mounted on 18
wheelers and park by rivers/ponds/whatever and produce ammonia gas from
water and air.

One time, I had to tow one of our Army 2/12 ton trucks to our Motor Pool
in Saigon.A guy there was drilling holes in the center of intake
valves.I asked him, Why? He said so the engine will keep on running if
the ignition gets to wet with water.
cuhulin