SAME OLE PROP QUESTIONS/ Please help

[boaterntexas]

I've read through the other post about props, including a very imformative "everthign you ever wanted to know about props...." but I couldn't find what I was looking for. My question is<br /> A larger number in pitch increases speed? torqe? if you wanting speed you look for what? for torqe what do you want.. and does dia. play any role?<br /><br /> thanks, <br />the guy with the old beat up 1976 boat that never works right.<br /><br /> Thomas

 

[steelespike]

Re: SAME OLE PROP QUESTIONS/ Please help

Not an expert but:<br />Generally speaking higher pitch number gives better top end lower pitch give more power, torque ie: better hole shot,more load pushing ability.Diameter is not as critical as pitch.<br /> Diameter is pretty much the result of the motor application.Diameter usually is involved with difficult applications.<br /> Always use a tach. and if possible a gps to<br /> check each adjustment.

 

[JB]

Re: SAME OLE PROP QUESTIONS/ Please help

Howdy, Neighbor.<br /><br />Think about your car or truck for a moment. Let's say you have a 3 speed stick shift.<br /><br />Would you drive on the highway in first gear? Would you try to start off in high gear?<br /><br />Choosing the wrong prop pitch would be doing one or the other.<br /><br />Your prop is a one-speed transmission.<br /><br />The correct prop is one that runs the engine at the top of its operating range of rpm with the throttle wide open, but doesn't allow it to over-rev. That is the top speed you can get with that engine. If you add more pitch you will go slower and overload and injure your engine, if you use less pitch you will over-rev and injure your engine.<br /><br />The correct prop for your engine depends on the load it has to push. That is why the best way to select the pitch is on the water with your boat and your engine, normally loaded, and an accurate tachometer.<br /><br />If the engine wont get to top rpm, that prop has too much pitch. If the engine will rev past the top of its range that prop has too little pitch.<br /><br />Hope that helps.