Offshoreonly.com - Over propped?

Offshoreonly.com (https://www.offshoreonly.com/forums/)

- Prop Talk (https://www.offshoreonly.com/forums/prop-talk-165/)

- - Over propped? (https://www.offshoreonly.com/forums/prop-talk/354133-over-propped.html)

My boat came with 28 bravos that never seemed right. I could turn them [email protected]. I ended up
buying a set of 29 hydros since the boat always felt like the transom was stuck to the water. I can only turn them 5100, but @81.8 mph. I’m told I’m over propped because the engines made power to 5500 on dyno. My question is what’s the point of spinning another 400 on a less pitch prop, at the same mph(according to the calculator)? Why wind them out for the same result on the top end, and probably worse mid range?

Better acceleration, You will get to the big number quicker. You will be easier on the drives not lugging them.

Quote:

Originally Posted by Sonichunter (Post 4628114)

If you aren't getting the motor to peak HP you are not achieving peak speed....period. Similar to many cars not reaching top speed in 6th gear, but rather 5th gear. You will have better overall performance with a lower pitch prop that allows the motor to achieve peak HP.
IF you ONLY want to cruise at say 3000-3500 rpm THEN you may opt for a higher pitched prop as it will yield better cruise performance but it will be hard on the motor at WOT.

I agree with these thoughts.
However, all marine engines have a WOT operating range that will not cause undue harm to the engine. I believe at 5100, you won't hurt anything.
The only way to know for sure where it is best to prop the engine is with a dyno sheet directly from your engine.

Brett