GIlow - in the interest of science i checked my perkins engine manuals
. they gave no reason as to why the injection pump pushes out more fuel
than the injectors can use. they did show a fuel
flow diagram which actually shows the injectors branching off the main fuel line which leads back to the fuel tank
- almost as if the injectors were put there as an afterthought.
in any case, while i was running my 4=108 today i decided to 'listen' to the sound of fuel being returned to the tank (i only have one). my tank is located under the main salon
and easily accessible. there was a steady flow of fuel - not a drip, drip, drip, and not a rushing stream, just a slow steady flow.
i'm thinking that the fuel may not be so much a coolant
for the injection pump as a lubricant.... but it's all conjecture on my part.