I am going to use the same engine from my 24' in my 28' I am planning on dropping pitch from 26" to 25". is this enough or should I look for a 24" or less. It is a lot more boat but I know several of you have gone this route before. Thanks, Chris

What HP engine?????? and what rpm do you want to spin it????

The 28 is a lot more boat so using the EXACT same motor I would think you would have to drop at least 2-3" of pitch IMO. I'm sure the people that have actually done it will chime in and tell you for sure.

Griff, it is about 500 at the propshaft. What kind of slippage numbers are you seeing? I have built a lot of torque into the engine so I can spin it anywhere from 5000 to 5500 and it is happy. Ideally 5400 when light and cold.

I think you'd be looking at a 24 Bravo. A 25 is not made in a Bravo.

As you saw from my previous post, I was running only 550 HP and had to drop down to a 24. I think a prop shop could turn it up to a 25P with the smaller diameter for RPMs.

Once I test my "New" engine at the 638 HP, I will be selling my 24 Bravo and running either the labbed 26 I have or a 28.

If I get my project completed prior to yours, you are welcome to try the 24 or possibly the 26 for shipping costs. If you like it we'll work something out.

Kirk

I think a labbed 26 will be your answer. Thats what I run with my 525sc. I bumped the limiter with a stock 24 at nuetral trim. My slip #'s are too high. In the 16-18% area. I've done about all I can to bring them down other than go to a 5 blade. I spin it 5100-5200.

Jo said he runs either a stock 24 or labbed 26 Bravo 1 's on the 28's with a 500hp.

Kirk, you are going to need a 28" prop for sure.

Prediction :

IF the 500hp comes from a 454 , then a 22" 4 blade , or if lucky a 24 4 blade , or a 23 mirage plus 3 blade .
If 500CI , then a 24 4 blade , or 26 4 blade labbed -

Good luck !

Thanks for all of the info so quickly. I had to make a quick decision on a prop on e-bay without test time to really figure this out. Now I have a 24 ,25, and 27 so I should be covered. Chris