Hi Steve,
I've not tested the new Enderle spur gear against the old style (called a "tuthill") Enderle...only a Waterman spur gear against a conventional Enderle for a customer a while back. Should be pretty much the same thing however.
In the tests of A/Fuel legal pumps of both types, the Enderle made more flow down low. Overlaying the results, the engine got more fuel down for the first part of the track, they were the same at 8000 RPM (where they are rated) and then the gear pump stayed straight and level while the conventional pump rounded off and flattened out a bit on flow as pressure increased beyond 100 PSI.
I don't think you'll have to worry too much about the differences in a methanol situation. In a nitro deal, having more fuel at the bottom could be an advantage when under rules like A/Fuel is. And that's exactly why the customer sent the two pumps!
The spur gear pumps have support (bearings) on both sides of the gear while the conventional only on one side. That's why conventional tuthill style pumps can't take pressures over 150 PSI or so for sustained periods. The spur gears pumps have no problem with 300+ PSI. Pressure isn't everything however.
Pressure achieved is always a function of fuel volume provided for a given set of nozzles, so if pump output were the same at a given point, then you'd see no difference in fuel delivery between the pumps.
As far as suction and picking up, I honestly think the conventional style might be better at that but I have not tested that. Just a hunch.
Spud
