I presume VDO is a brand name and not a type of sender. See some in Aircraft
Spruce and Summit Racing catalogs that weren't too pricey but was unsure of
the quality. I found an oil press. gauge I liked but no water pressure
gauge. I'm leaning toward all electrical gauges.  

Speaking of water pressure gauges, since I want to use a water heater core
for cabin heat, could the pressure tap be up front (pusher plane) or would
the flow when heat is used cause a wrong reading?

 

Wendell

 

It would work, but I think it best to have the gauge somewhere near the
outlet side of the pump - where the pressure is the highest, and the filler
cap connected to the plumbing somewhere near the inlet to the pump - where
the pressure is the lowest.  Again, an electric sender is a good way to go.

 

FWIW,

 

Al