Torque roll
 

2006 Sunsation 288 MCOB. Sometimes while cruising out of nowhere the starboard side is damn near at water level. But oddly it’s not all the time and can’t figure out why. Yesterday I was running a 4blade bravo 1FS and it was bad. I’ve ran a 5 blade also and it does it also. If I drag the starboard tab I can level it out. Is there any way to make it go away or not be as bad. I just ordered a new 5 blade prop yesterday after begging several componies to sell me a prop. It’s impossible to get in touch with them so figured I’d ask here first. wondering if prop choice can maybe help or maybe drive height or something. Current drive height is 3” prop to pad. Bravo XR with ITS. Prop I ordered is a herring 5 blade 27 pitch 15.5 diameter 22 rake.

FJ propeller in Ft Lauderdale has always answered the phone anytime I have called. They do great work there and have other locations as well including one at LOTO and I believe they own Hering now as well.

Thanks, I bought direct from Herring. I’m going to call back and discuss with him because it was one of the things on my list to ask about but I forgot. It’s 3-4 months out so I’m sure I have plenty of time to adjust. Reading other posts I’m thinking the recommendation is going to be to stay away from a 5 blade but it’s not any worse with a 5 than a 4.

Dagwell,

What's your drive ratio? Any slop in the gimbal?

I can't imagine Sunsation would have sold a boat that listed that bad. Stock power? I ask about drive ratio because prop pitch is the major contributing factor for torque roll. You could maybe drop pitch and increase drive ratio and reduce torque roll. We go about it differently, being direct drive, but we can often reduce prop walk in our model boats by reducing pitch and running the engine in a higher RPM range.

Thanks. Brad.
(937)545-8991

I do NOT know if this is the answer to your issue, but it may be an option.

https://www.boatzincs.com/mercruiser-zinc

Attachment 577451

If you scroll down through the zincs that mount to the cavitation plate, above/behind the prop, you will notice that they have options for different ones that a fin to them. I have seen those installed slightly off from directly aligned with the drive, in an angle that will counter the prop torque.
Again, you will need to talk to an expert to see if this is something you can/should try.

Have you talked with the folks at Sunsation? That would be my first call.

Padraig

It would be interesting to understand how some Super V class racers are turning 6 blade Herrings and a 1.5gr without a problem. I like the idea of spreading the load to 6 blades and it has been described to me as "smooth as butter".

Okay, thought i remembered a different drivability thread by the op. See this;
https://www.offshoreonly.com/forums/...-slipping.html

So, between the two threads, something is substantially off with this boat. Design ? Propping ? Rigging ? Mounting ? Driver ?

Only boats i’ve been in that rolled to one side that much, where bow steering. Interested to see what ultimate cause of these issues are for the OP and this boat.

so as for that last post I ordered a new prop and have tested a 5 blade and concluded there is nothing wrong with the boat it was a prop issue. Maybe it’s bow steer and not torque roll. Boat has no issues when getting on plane or at wide open throttle sits flat. But at lower cruising speeds sometimes it just happens. I’m new to boating and maybe it’s operator error 🤷‍♂️ But I’d low to know what I’m doing wrong.

thanks maybe that will help. I’ll look into it.