Reply To: Cummins QSC 8.3 Aftercoolers

[Tom Bartolomei]

With my M7 prop set @2600RPM, I was getting 27-28kts at slack tide with 50% fuel, full tools/rations, 2 adults, a 12′ AB dingy w/40HP outboard on the Freedom Lift, clean bottom, and 100′ (~150lbs) of 5/8″ chain up in the front anchor locker. I believe the Sabre 48 hull #1 sea trial was conducted with M7’s, 100% Fuel, 100% water, no waste, no dingy, clean bottom, 6 adults, no tools or rations.

With the M2 prop set @2600RPM, I now get 23.5kts, at slack tide, 100% fuel, waste, 100% water, full tools/rations, 2 adults, same dingy configuration on the Freedom lift, clean bottom, and now 300′ (~450lbs) of 5/8″ chain up in the front anchor locker. Lost some speed but lower fuel burn on the engine at that cruising RPM. 23kts is still hauling in my book for this boat.

I’m pretty happy with it now and I don’t think I can do much more. Sold one pod worth of M7 prop sets to a marine shop in FL. One more pod’s worth of M7s to get sold. Going to hold on to my set of M5’s as spares since these things are so expensive and hard to source with any reasonable speed.

Tom