Bravo one 4 Blade
 

I am re-powering my ZX 28 with 383 Strokers, I was running 5000 rpm with 26 pitch Mirage 3 blade stainless, they never did plane very well. I need 5200 rpm with a 4 blade, will a labbed 28 4 blade get me there? or am I going to be closer to 5400rpm?

I'm a newbie at performance boating so you should not consider this as info from one with lots of knowledge.
My guess would be that you'll lose rpm's down to the mid 4000's because of the increase in pitch and the additional load of the fourth blade.

See ya,
Kelly

What did it have for power previously? Mirage props come in odd number sizes so what you have should be a 23,25 or 27

I was running twin 350's at 5000 rpm, on 3 blade 26 pitch stock Mercury Mirage props

Start with a 24p bravo one and them have it labbed to your liking. Going up in pitch will bring your rpm's down. With the biiger motors you're need to go up but that can be labbed back in.

Thank you for your help Poker, I have spotted 2 labbed 24's

Are you running 1.65:1 or 1.5:1 gear ratio?

My 292 with 1.65:1 outdrives and 6.2L (377ci) engines (320 HP) turn labbed 28p Bravo 1 four blades over 5000 rpm. What horsepower do you expect out of the 383 strokers?

1:5:1 should be 350 HP and would like to get to 5200rpm (MFG Specs)

So you were running 5000 rpms with the old engines and the 3 blade props? If so run your current props and see how the boat responds. Much easier to make a decision then.

Okay, that makes sense. I agree with running your existing props first.

Also, if you haven't seen this thread yet, it has some info on props for that hull. Good luck!

http://www.offshoreonly.com/forums/d...eed-28-zx.html

Thank you, very informative, looks like there is no real answer with out trial and error, I had the same experience dialing in my F-150 Lightning

Too many variables.

Are your existing props Mirage or Mirage plus?

Were they re-pitched as Mirage and Mirage Plus come in odd sizes? So they would be 25 or 27, not 26.

What hp were you previously? 300?

What speeds were you running before? I would assume around 70mph? 1.5 ratio with 25 props at 10% slip is 71mph. Guessing on the slip.

Let's assume you were 300hp before running 25 Mirage Plus props at 5000 rpm. Now your are 350 hp and want 5200.

My guess is you will be running a 25-26 4 blade and should pick up 4-6 mph. But, that is with a lot of assumptions. But I figured what the heck I'm bored waiting for paint to dry(literally). LOL If you run your current props you can get a much better idea what direction to go. Just by picking up 200 rpm you will get mph.

A Rev4 25 might be an excellent choice. If that is too small look at the Bravo line.

I build 350s for my Chris Craft Stinger and have 377"s in my 29' Fountain. If you just freshened up your 350s adding the bore & stroke, no other changes, you have probably added enough HP to go up an 1" in prop pitch (somewhere in the 20-25 HP per engine I am guessing). I have Bravo 1 - 4 blades on the Fountain 26" pitch. If you are looking for a good starting point I would try the 26" pitch version. At least one of the supporting prop vendors will rent you props. I read where the charge was $90... This would seem like a good way to go. There are several very experienced owners who often chime in on prop advice. When I added about 100 HP to my CC Stinger I was able to go up 2" in prop pitch and added 4-5 m.p.h. The Stinger was not a fast boat like the newer step hulls so you may experience bigger gains. Good luck! Enjoy your newly re-powered boat.

Never seen or heard of that size pitch in neither Mirage or Mirage+. What is the part number?

Brett can you chime in here?

they are stamped Mirage 26p, I found some labbed Hydromotive 4 blade 25's to try. Both engines should be in the boat this week so I can try them both and get back with you and let everyone know what worked (hopefully)