Offshoreonly.com - Props for the 400R motors

Quote:

Originally Posted by Jamie77905 (Post 4367073)

Ok guys here the question. Putting a set of Mercury Racing 400R outboards on a 32ft Spectre Cat. Has anyone ran these motors on a cat yet? I am looking for a starting point on props, everything I find is based on them being run on a deep v center console. Any help will be appreciated.

I was out at Skater and then Mercury racing recently dialing in the new Skater 318. Im not sure of the weight of your rig but mine is 5500lbs and roughly 31 foot. It was widened 10 inches on the standard 308 hull. Mercury ran 4 blade cleavers and 4 blade Bravo FS props 33 inch both. Not sure of the diameters. They ended up Making a set of CNC 5 blade 33 pitch 15 diameter cleaver props. None of the four blade props ran very well. The Bravos ran up in the 106mph range at 7000 rpm. Slip was 15%. Not great. Most of the guys running bravos are around that slip # but not everybody. My rig ended up at 114mph with 5% slip with the motors 1 3/4 inch above the bottom I think. We raised them to 2 inches where they kept them and slip ended up at 8%. Acceleration was better up there. Thats pretty damn good. I don't think the set up has anything left in it. Merc thru everything they had at it. In order to get that engine height we cut water ramps in the bottom of the boat which allowed us to keep pressure up at 2 inches. Problem with these props is that they won't be out to the public until another 10 months or so and they're not cheap although none of them are. I had to take them as the boat needed 5 blades to really run right. I think Im gonna get a set of the Bravos as back ups in case something happens. Again Im not familiar with Spectre boats and this is all new to me. My boat is actually very big for a 30 footer. ask anybody who has seen it. It runs awesome with the 400s Can cruise at 95mph at almost 2 mpg. Im pretty sure it would not have gotten over 100mph with the 300s because of its size. The 400s gave me at least 14 mph over the 300 motors and Im pretty sure Ill see more at some point under different conditions. Boat hit its numbers with 1 person, approx 100 gallons of gas and glass flat fresh water. Motors pushed that rig to an everyday number of 114mph not once but repeatedly over a three week period. I also only have the motors on three inch jackplates mounted right to the hull which has no notch in the bottom. They seem to like it closer to the boat. I think it may be possible to get a bit more from a different version of this Merc prop but thats a story for another day. Good luck with your quest. Thes props worked well for me but my rig is new and was kind of an experiment as one was never built before. Steve.