Prop size

[Toolsntoys]

I have been researching engine options for my 53 my. In doing so I was working with a reputable prop shop to determine what props would be suited for each desired power package. My Hatteras build sheet says that my boat came with 23x31 4 blade Michigan props. The prop guy can’t figure out why Hatteras used these and didn’t use a lager diameter. He is telling me that the boat should have 28” props. Thought?

[Boatsb]

Either theres a misprint or you have a prop that cant exist.

You should have a 28" diameter prop.

2" shafts do not fit 23" props. The diameter and hub size would make it outside of the norm.

I know theres a diameter minimum and maximum for each shaft size.

[KPTIM]

According to the Michigan Wheel technical catalog a 23 inch diameter wheels can have a 2" max prop shaft with no problem.

The survey report from my last survey says my props are 22 x 23 and I have 2" shafts.
I can see the 23 diameter wheel but that 31 pitch is bit much for a 53 with 8V71's.

I will check my build sheet tonight and also see what the spares are in the bilge.

[Toolsntoys]

Here is a pic of my build sheet

[dsharp]

Prop size will depend on the ratio of the reduction gears that were used.

[Boatsb]

Just replaced 2 4 blade 26 x 32 with beams. High speed (35 kt vessel)

Also spoke to the acme guys. Was told the minimum they did for our need was 24 or 26 inch on 2" shafts. It's all part of the hub size and stress based on hp.

Its a science now. Less gut and guessing. They make some nice CBC props.

I'm sure they are far more efficient than older designs.