Bravo 1 Questions - True pitch and diameter?
 

Just got my prop back from Black Dog. It is a stock 26P Bravo I, 4-blade. Not sure if it had any previous work done on it. As shiny as it was, I would assume not. The edges of the blades were all "smudged-up". No serious dings or damage in the blades that I could see.

I sent it out to be cleaned up and brought back to specs. The Prop Scan report that came back with it had the pitch of all 4 blades at 24 and the diameter at 14.750.. ????!!!! I thought they should all read 26P and the diameter is supposed to be 15.25? Am I missing something?

I think the diameter is suppose to be 15.25". Bravos are always pitched a little less than stamped. But, from what I have read it's about .75 lower. So, a 26 would actually be a 25.25.

Sounds like your prop may have been re-pitched and some diameter taken off at some point?

Most bravo's come in at 15.00 and pitch it typically .7 less of stated pitch.

What effects will the reduced diameter have on performance? Looks like this one may become my "spare". Damn.

It will raise your rpm a bit. I would at least give it a try.

I have written pages on this over the yrears if you look back through the forum.
It gets rather in depth but it really doesn’t have too.
The "most" important thing is for the propeller to do what it needs to on your boat. Sometimes it's just better to let the prop shop pros worry about the numbers. It will give you less headaches.
I will try to put this into a condensed version.

Bravo 1 props are marketed at 15.25" diameter. The 34 and 36 are. The rest are smaller and slightly varying.
The actual pitch varies 1-2 inches when measured on a MRI or Prop Scan tool. The tool does not take into consideration the effects of the cup. It does measure them but does not understand the reality.
There are other issues involved that has to do with the timing of our development of these prps over a 6 year period.

Bottom line is, if you run them in order with the ability to turn them all, you will find 350-400 rpm difference between models. That's what matters.
For your own calculations, use .7 to 1 inch of pitch less than stamped for slip % numbers.

Prop scam I mean scan tools are just that, tools. In the right hands they are invaluable. In the wrong hands they can be a great labor selling/creating tool.

Redhook, your prop stared life at about 14 7/8" diameter and 25.25" of pitch.
Diameter reduction can do many things. One of them is rpm increases.

I can't give away to much information. I've done this for years for free. Some folks now use it for their own businesses. LOL

Call me if you want to learn more.

Brett

Thanks Brett! I will give you a call tomorrow. I appreciate the information!

mirages the same way? i should consider my 23's 22's?

Good info here! Thanks BBlades.

For the Mirage series, use the pitch stamped on the propeller for calculations.

Except............27's use 27.5 and 29's use 30.5

Don't ask. LOL

Brett