Nomad Willy
Guru
Al,
"MP" is a model name and style of prop .. like the one in my pics. It stands for "machine pitch". NOT to be confused w the "MP-3" prop. The MP-3 is a skewed propeller that is more typical and not symmetrical. The "MP" prop is symmetrical. My prop .. the one in my pics. The MP-3 prop is a good prop too but not as well suited to slow speeds as the MP.
Your last post was confusing. If you are confused about the;
1. propping to rated rpm
2. over or "cruise propping"
Go to our archives and read reams of discussion on the matter.
Call Michigan and ask them. FF coined the expression "cruise prop" and I don't think it's used anywhere off this forum but I really don't know. The cruise prop is basically a trick that can be used by anybody and less noise and about 5% greater economy can be had but there's a real danger that the engine may be overloaded and under what circumstances is a bit of a foggy issue.
As far as I know most or all engine manufacturers recommend you prop to the engines rated rpm. Then the specs about how long you can run at WOT and the highest rpm you can run continuously are applicable. All that is out the window when you over prop.
As I've said call Michigan or/and check specs of engine manufacturers to see what they recommend. Then your eyes will be wide open (as they say) and you'll be prepared to choose how to prop your boat. I will always prop to rated rpm but many here on TF over prop and prefer that to the standard method.
Eric
"MP" is a model name and style of prop .. like the one in my pics. It stands for "machine pitch". NOT to be confused w the "MP-3" prop. The MP-3 is a skewed propeller that is more typical and not symmetrical. The "MP" prop is symmetrical. My prop .. the one in my pics. The MP-3 prop is a good prop too but not as well suited to slow speeds as the MP.
Your last post was confusing. If you are confused about the;
1. propping to rated rpm
2. over or "cruise propping"
Go to our archives and read reams of discussion on the matter.
Call Michigan and ask them. FF coined the expression "cruise prop" and I don't think it's used anywhere off this forum but I really don't know. The cruise prop is basically a trick that can be used by anybody and less noise and about 5% greater economy can be had but there's a real danger that the engine may be overloaded and under what circumstances is a bit of a foggy issue.
As far as I know most or all engine manufacturers recommend you prop to the engines rated rpm. Then the specs about how long you can run at WOT and the highest rpm you can run continuously are applicable. All that is out the window when you over prop.
As I've said call Michigan or/and check specs of engine manufacturers to see what they recommend. Then your eyes will be wide open (as they say) and you'll be prepared to choose how to prop your boat. I will always prop to rated rpm but many here on TF over prop and prefer that to the standard method.
Eric
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