Prop help, please
 

Recently bought 1989 23' Webbcraft Velato, 454 mag engine, tag on valve cover states 365hp. At WOT it's turning 5200 rpm according to the factory tach and running 57mph according to phone app. The rpm seems high to me. I believe it's the factory prop, quicksilver 48 13704 A40 23p. 13" diameter. I think this will be ok for skiing, tubbing. But I'd like a cruising prop to get the Rpm down & the mph up. Any recommendations much appreciated, thanks in advance!

I dont know the specific boat but on a 23 foot boat with a 454 mag, 23p is in the right neighborhood.. the 13" diameter sounds a little small though, See if you can borrow something like a 23 mirage or mirage plus to try

I'd leave it alone. 5,200 is perfect for a mag engine. You prop up you'll not like the no throttle response. If u try a 25 p mirage you'll drop to about 4,800 and probably drop a little too end and it will feel like a slug.

I'd try a 24 pitch Bravo I 4 blade.. Will likely improve you hole shot and bring the slip down for increased cruise speed....

agree a 25p mirage would be way too much. The thing is he says he is doing 57 with a 23p prop at 5200 rpm. Thats a lot of slip. With the right 23p prop he should see 57 around 4400~4600 rpms. I dont think that 13"diameter prop has enough blade for the boat. A 23 mirage will have a largewr diameter and more blade area which should get his slip down, plus its one of the most popular props out there so finding one to borrow and try should be easy. If it will pull it the 24 Bravo Boatally mentioned would be nice

Thanks for the input guys

Regarding the 4 blade, stay with the 13" diameter?

nope... four blades can be tricky.. the most popular 4 blade in our world is the bravo 1. The general rule of thumb is to drop pitch when adding a blade, however with the B1 thats not always the case. You also need to figure put what the boat wants for a prop... bow lift? Stern lift? Your best bet is to borrow props and try.... Or call BBlades, they have a program where you can try props and may have a really good idea where to start.

The boat also has trim tabs, I'm not in touch with enough people to borrow props so maybe bblades is the best option

The boat is older and going to have a deep X dim. I don't think you'll see the best overall performance from a 4 blade.
I would start by trying a 23" Mirage Plus prop.

Also, if you try a Bravo prop, the 24 pitch listed is not the actual pitch of the prop, it will be closer to 23.2. If you are going to try a 4 blade I would go with a 22 Bravo. I don't think you are going to spin a 24. It sounds like your prop has had a lot of damage/repair done to it over the years, and because of that the diameter is really small. Just getting a good prop no matter 3 blade or 4 blade is going to make a big difference.

Deep X dim?

technical crankshaft centerline from keel on vertical axis, in english.. how deep your prop is in the water.

Thanks guys!

Ok, learned that I incorrectly measured the prop diameter. It's more like 14.5 " it's supposed to be. Prop gods straighten me out on that, thanks Ken. So now I'm wondering if it'll turn that 23p prop to 5200 rpm will it pull a 25p to net better cruise economy & better top end? Boat weighs 3800lbs. I was told the part number = a early mirage prop.