Donzi 35ZR - 496HOs
 

Current settup
Mercury Marine 4 blade 28p LH&RH
5100 RPM starboard
5000 RPM port
max speed gps 77mph

Had Peter Dean here in GA, measure and my actual pitch is 25.5 LH and 26.5RH. Explains 100 RPM difference
Peter says normal to see 2 pitch size on newer props etched with Mercury Marine
Peter says the props etched Mercruiser measure more accurately to what’s stamped.

I like to hole shot with The 28s and for running around the 28s that I have work well. Or 26s LOL

I want to have Peter build me a new set, for maximum top end speed for fun runs.

Question. - what is the best target RPM on these 496HOs that I should have Peter design new props to?
I have read a bunch online and I think people just say what ever they want, so I see anything from 4500 to 5200.
I would appreciate some solid advice.
thank you.

You should’ve been getting an over rev alarm if you were at 5100rpm. WOT range on a 496 HO is 4600-5000. Tell your prop guy that you want props for top end and they should be able get you there, ideally close to 5000rpm

I would go for a set of labbed 30p props. I had a similar setup to you on a 32 Sunsation and I could run a set or 28s for an all around prop with the boat loaded up or the set or labbed 30s when the boat was on the lighter side. It would pull just under 5000 rpm and run right at 80 and the cruise speed was better with the 30s as well. Only downfall would be when the boat was on the heavy side it would only turn about 47-4800 and run a few mph slower. Hope this helps.

Stole this performance report from member ‘boatnt’ on a recent Fountain thread. His factory performance report shows 5150 max rpm’s on both engines. I understand the limiter is set at 5150 which is exactly where my old 27ZR peaked with a single 496ho in ideal conditions.

https://cimg5.ibsrv.net/gimg/www.off...a6209e380.jpeg

RR

good info and thank you. So, you run the Ho’s right up to 5-5100. I was thinking that we wanted the prop digging in the water at lower RPM, less trim for max MPH, closer to peak torque.
The weight is also a piece of this puzzle too. Didn't think about that so much and it was 300 RPM delta for your sunny. the info you shared is super helpful, so I can track see what my settup does.

Hydromotive 5 blade
 

New his week I found, a pair of Hydromotive 5 blade 28p with test time only. From what I have learned these should improve hole shot and mid range, but might hurt top end. Considering my Bravo 1s Mercury marine props measured at 26 even though stamped is 28, I thought I would give this a try. It will be a couple weeks before I get back on water due to some family things, but this should be a good experiment. If nothing good comes of it. These will find a new home and the price is good. With only. Few hours on them.

I've had a few 496HO's and I always propped for 5100 full fuel in cool spring or fall conditions, puts you in the sweet spot for dead of summer heat, but keeps you off the limiter of 5150 when the air is cool and dry, just my .02