In theory is mechanical liquid injection possible?

[Dent2]

Was looking at an old Hilborn mechanical injection set up today and it got me wondering if it would be possible to convert it to Liquid propane? The big problem I see is the engine driven fuel pump, is there anything out there that would work for this application? I'm thinking it would need to be fairly high pressure to ensure there would be enough pressure in the bypass to return to the tank. Am I way out in left field or is a mechanical injection setup possible?

[BigBlockMopar]

Digital liquid propane injection is difficult enough already, pure mechanical would be pretty much impossible to properly meter I think.
Fuel-temperature plays a very big role with propane-pressure and therefore mixtures. A few degrees warmer and mixture becomes much richer.

If you can control that, then you've tackled a big problem. But you won't be able to do that without a feedback system in the form of an AFR-sender in the exhaust.
Perhaps with a dragrace engine where only fullthrottle-mixtures are relevant you might get away with a cruder system.

[Dent2]

Would be for a mud truck, so more or less the same as a needs as a dragster. I was thinking if the engine driven pump put out enough pressure you could regulate pressure with the bypass and maintain a constant injection pressure.

[franz]

Temperature will play the biggest game changer. I would say its possible but unfeasible in practice.

Franz