patos

I have one Bravo 1 22P 48-831910 Lab Mercury Marine
And one Bravo 1 24P 48-831912 Lab Mercruiser
The thing is that they don't look the same.
The Mercury Marine is thicker at the start of the blades and it looks like they are reinforced in a way but the blades are really thin after that.
I can see all the stripes after grinding/ polishing of the hole prop.
In the center there are 4 walls. They are formed like turbine.
On the 22p number the second digit is stamped.
The blades on the Mercruiser prop are the same thickness but at the start of the blades they are as thin as the end of the blades.
It looks like they can break easy.
There are no polishing stripes at all and the 4 walls in the center are straight.
Is one of the props old or is there difference between Mercury Marine and Mercruiser props?

GTOFFSHORE

Mercruiser props are the earlier ones but the diff would be in who and how labbed. Why each was done the way they were is for someone who knows props too look and the blades and explain what was done.

patos

I have now tested both props.
The 24p Bravo makes a little vibration coming off plane.
I can't feel any vibration other than when I let off the throttle completely.
I'm wonder if it's prop out of balance or cavitation.
The 22p has better grip,but again another pitch and lab.
I'm thinking of ordering a brand new 24p instead of sending it for balancing/check,but afraid it doesn't help if it's a cavitation problem.
Any one else had vibration only when coming off the throttle?

bbladesprops

There is a difference in the depth of the hub bores between the props. The Mercury Marine (newer) is shallower.

Are there any hand stamped numbers on the inner hub where the nut would go?

Brett

patos

No stamps on th 24p, only on the 22p,but I measured from the end of the blades to the cavitationplate. One blade was different from the others.
I will deliver it for control.

I didn't get an answer in another thread,but maybe "Prop testers" know more about it.
The Bravo prop has better grip and larger diameter,but one thing that got worse is the leaning to the left side.
Does it help to move the engine a bit to one side or do I get another problem/disadvantage ?
I can compensate with the left tab,but thats not ideal.

bbladesprops

In some stern drive applications, changing rotation helps to combat the list.
Possibly changing the weight distribution in the boat will help.

Brett

patos

What about 5 blade. Better or worse ?
I asked for a gearbox with opposite rotation because I sit on left side and more weigt on that side,but was talked away from it.