What is Propeller HP?

[thralph]

I own a 1983 Evinrude 35 HP outboard. In 1983 horsepower ratings were reported at the cam shaft. Today they are reported at the propeller. My engine has good compression (over 100 PSIG in each cylinder with 5 PSIG separation). What is the "best guess" propeller HP rating for this engine?

 

[Dhadley]

Re: What is Propeller HP?

Some older motors were rated at the crankshaft, it doesnt have a camshaft. The gear loss is about 10% or less on the smaller motors so your rating falls within NMMA's 10% rule. It's still going to be about 35 at the prop.

 

[walleyehed]

Re: What is Propeller HP?

32-33......

 

[walleyehed]

Re: What is Propeller HP?

Typed same time again....follow Dhadley's post, if he says 35, it's 35.

 

[Dhadley]

Re: What is Propeller HP?

It'll be very close as you mentioned Kenny. If it was say, 37 at the crank it'll still be over 33 at the prop. Either way it falls within the 10% guideline rule.

 

[walleyehed]

Re: What is Propeller HP?