Arneson Surface Drive Issues
#11
Banned
iTrader: (1)
I'm wondering if anyone else out there has had similar issues as I did converting I/O drives to arneson surface drives. I have an express cruiser Formula 370SS which is a bit heavier 16,000lbs and beam of 10'6" than your typical off shore boat. When I installed the drives over a year ago I couldn't get the boat up on plane. Most of the props made for that drive are at most 18" dia. I was getting too much prop spin or cavitation to push it up on plane. Then I had larger props custom built they were 22" diameter 6 blade 26 pitch. Now I have too much prop and the engines won't turn past 2000 rpm and still can't get up on plane. These props are super expensive as you know and this is a very tedious process. Is there another solution out there that I don't know about? Ric over at Arneson hasn't been any help. Thanks.
Is this it?
#12
Registered
What engine/power do you have?, those formula normally come with Bravo 3 drives and 1.81:1 or 2.00:1, what reduction are you using with the Arneson? 1.50:1?
We used on deep V 55' (22.000lbs) twin Caterpillar 3126/425hp with 1.75:1 Reduc + Surface Drives + 5 blades 24''dia x 30'' pitch props and ran 36mph loaded without ventilation tubes...
To go on plane, Just trim the drives a little up and when the engine start to got rpms, down the trim slowly and still acelerating with the throttles...
That's a easy way to know if your boat need the ventilation tubes with 6 blades and 22'' diameter props (Sound like a 6 blades props with 22'' diameter are to big for a 37' boat)
We used on deep V 55' (22.000lbs) twin Caterpillar 3126/425hp with 1.75:1 Reduc + Surface Drives + 5 blades 24''dia x 30'' pitch props and ran 36mph loaded without ventilation tubes...
To go on plane, Just trim the drives a little up and when the engine start to got rpms, down the trim slowly and still acelerating with the throttles...
That's a easy way to know if your boat need the ventilation tubes with 6 blades and 22'' diameter props (Sound like a 6 blades props with 22'' diameter are to big for a 37' boat)
#14
Registered
here is a link to my boat with the Arneson 7M conversion. http://47excalibur.com/ ... final prop size ended up being 20'' x 27 x 18* when the props were 22'' it jumped up on plane but hurt my top end. cut them down to 20'' and now its perfect. sounds like you dont have enough torque in those motors and need the vent tubes to help out...but getting on plane make sure the drives are straight out bc if there in the down position you will never get her up