Cummins RPM's

bluefin650

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Looking to find out if the RPM's are automatically governed with an electronic QSC 8.3? I am looking at having a prop reconditioned and they think that there is a possibility of loosing 1/4" of material on the total diameter of the prop.
I'm just trying to find out if the engine will compensate for the decrease in drag and a possible increase in RPM?
 
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Tuna Pursuit

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I'm not sure about the governor but you need to make sure it makes max rpm with no load to start. The prop shop should give you a spread sheet to fill out with different rpm readings in order to dial in what you need.
 

BillD

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27 H&H with Cummins QSB 5.9 480 power
Looking to find out if the RPM's are automatically governed with an electronic QSC 8.3? I am looking at having a prop reconditioned and they think that there is a possibility of loosing 1/4" of material on the total diameter of the prop.
I'm just trying to find out if the engine will compensate for the decrease in drag and a possible increase in RPM?


Bluefin,

Read this over.

Prop to the upper engine on the range

Propeller_sizing[1].jpg
 

captainlarry84

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Photo tach the boat at WOT in no load to make sure she is hitting the governor.
On the wheel, I would re-pitch before losing any diameter. The edge of the blade does the bulk of the work. A cut 23" wheel is not the same as a factory 23". Once cut you cannot go back. Re-pitching is much more forgiving.
 

bluefin650

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Decreasing the diameter was not my first choice. The tips of the blades are chewed up pretty bad and it is assumed that I will have to loose some diameter to fix them.
 


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