TIMINATOR

The boat is a single step Eliminator 25 Daytona running a B-Max drive 1.31 or mebbie a 1.28 ratio. Powered by a 565 with all of the goodies topped off with a 14-71 and chiller. The X dimension seems pretty high as running at anything over 80+ you can see the top of the prop, from the prop nut/upper part of the hub totally out of the water when behind the boat. Original prop was a rebuilt,(by an inexpensive general prop shop)Bravo 1 30" 4 blade. Best speed was 114-115 at 5900 rpm. Local lake is at 2200'. I had a "professional" hot-rod prop shop go over it, they thinned the blades, equalized the pitches (said that they were terrible!),built up the front blade edges (said that the last guy must have just ground them back to smooth them rather than do it correctly with weld), and "put the cup back to where it should be" and bead blasted the last 1" of the blades. He said that with all of the work, I should gain 5 to 8 mph, I thought that optimisitc. Testing at the same temp within 4 degrees, showed the gain to be 1 to 1 1/2 mph at best, what a disappointment! Same rpm as before. I had borrowed a P5X Hydromotive 31" 5 blade, and it dropped the rpm to 5300-5400 rpm and ran 123-124 mph. My power peak seems to be at 5900 rpm so I think my next move is to a 28" P5X Hydromotive. I hear that the Maximus is a stern lifting prop and at 15 5/8" would also be too large of diameter for what I have. I think that I need the extra blade area in the water for the top speed, and the low end and midrange with the P5X is awesome! C'mon prop gurus! Any comments? TIMINATOR!!

bbladesprops

First, something is wrong with your numbers. If you have a 1.31 g.r., the 31 Hydro would be runningat a negative slip%. Varify your numbers and we can look at this again.

It does seem the 5 blade is helped by your high X dimention. I find your story about the prop shop welding up the LE interesting. That is touchy. He is right however, in that it should of been done right the first time using what material was there to help the weld take better. Bead blasting the TE was something we did at Merc years ago. We don't do and neither do they for many years.

If you would like to try some 5 blade Maximus propellers, we can supply you with them.

Thanks

TIMINATOR

Tach doesn't read the same with original bravo prop, must be funky. Speed went back to where it was though. Teague and several others say Maximus is too big diameter and also causes stern lift. Say they cut them to 15" or 15 1/4" before sale depending on application. Isn't that what a Hydromotive is out of the box? I have a stock 28" Maximus for testing and a 28" Hydromotive coming. TIMINATOR

bbladesprops

Try both propellers and then we can discuss the outcome. The Maximus propeller has many different Labbing options. It is bigger than the P5X to begin with.

When ever you test something new. Do it causiously.