JoLin
Vice Admiral
- Joined
- Aug 18, 2007
- Messages
- 5,146
Just wanted to share my experience with doing a lot of research to come up with a solution to an unusual (for this forum) problem.
My bost came to me with a pair of 19P Merc 'Vengeance" 3 blade stsinless props. The usual calculations showed that they're the right props for the boat. They ran right up to the 4800 rpm max range for my motors, and I hit a top speed of 39 mph in calm water. Not bad for a 10,000 lb flybridge cruiser!
The problem? I boat in a big, shallow bay that's famous for big afternoon swells and a lot of chop. My boat's a tail dragger- to stay on plane I had to keep the speed up to a minimum of 22-24 mph... at which speed I was usually pounding the heck out of the boat and passengers. Not pleasant at all. Top speed simply wasn't a concern. I almost never have a reason to push it past 4000 rpm.
Given the expense of changing 2 props I didn't want to screw this up. A lot of research on my own convinced me that switching to a 17P, 4-blade "stern lifting" prop might achieve what I needed- namely, a lower minimum planing speed. I also wanted to keep the engine revs up so as not to "lug" the motors. I'd more or less settled on Solas Titans. I like Solas props, and I'd had good results with the Titan on a previous stern-heavy boat.
After a lot of hemming and hawing I broke down and went to a local prop shop- Bossler and Sweezey are well-known experts on Long Island. I didn't share what I'd come up with. I told him about the boat and what I was trying to accomplish. I answered his questions and in 10 minutes he'd come up with 17P Solas Rubex 4-blade props- more or less what I had in mind. I mounted them last season.
The difference has been like night and day. Depending on conditions I can maintain plane down to 16-19 mph at 31-3200 rpm. It's made a huge difference in our enjoyment of the boat.
My .02
My bost came to me with a pair of 19P Merc 'Vengeance" 3 blade stsinless props. The usual calculations showed that they're the right props for the boat. They ran right up to the 4800 rpm max range for my motors, and I hit a top speed of 39 mph in calm water. Not bad for a 10,000 lb flybridge cruiser!
The problem? I boat in a big, shallow bay that's famous for big afternoon swells and a lot of chop. My boat's a tail dragger- to stay on plane I had to keep the speed up to a minimum of 22-24 mph... at which speed I was usually pounding the heck out of the boat and passengers. Not pleasant at all. Top speed simply wasn't a concern. I almost never have a reason to push it past 4000 rpm.
Given the expense of changing 2 props I didn't want to screw this up. A lot of research on my own convinced me that switching to a 17P, 4-blade "stern lifting" prop might achieve what I needed- namely, a lower minimum planing speed. I also wanted to keep the engine revs up so as not to "lug" the motors. I'd more or less settled on Solas Titans. I like Solas props, and I'd had good results with the Titan on a previous stern-heavy boat.
After a lot of hemming and hawing I broke down and went to a local prop shop- Bossler and Sweezey are well-known experts on Long Island. I didn't share what I'd come up with. I told him about the boat and what I was trying to accomplish. I answered his questions and in 10 minutes he'd come up with 17P Solas Rubex 4-blade props- more or less what I had in mind. I mounted them last season.
The difference has been like night and day. Depending on conditions I can maintain plane down to 16-19 mph at 31-3200 rpm. It's made a huge difference in our enjoyment of the boat.
My .02
