Cavitation in Reverse

[Vince Luciani]

Hello everyone,

It’s been awhile since I last posted, but the repower (completed July 2007) has been awesome. I’ve got about 300 hours on the Cummins 330’s and everything has been great. A true testament to doing things the right way (i.e., following the advice of Capt Pat and others on this board) is that I have had no problems with any of the systems that I installed. (No monkeying around with annoying little stuff not holding up, etc.). Thanks again.

I saw a comment that Bruce made in another post about cavitation in reverse being worse with 3 blade props versus 4 blade props and that comment prompted this post. The cavitation of my props in reverse is terrible. If I try to go in reverse with any real speed, the boat vibrates pretty bad. The port seems worse than the starboard. I know all boats cavitate in reverse (at least all the ones I’ve owned before) but they were not like this. Is there anything that can be done to lessen this? Can the props be worked in any way to lessen this? I’m wanting to back down hard on some big fish! LOL My props are 3 blade, nibral, 20.5’x23” with slight cup.

Thanks guys,

Vince

[In Memory of Vicroy]

Vince - if it makes you feel any better, they all shake & bake in reverse under a good bit of power. The boats at Tropic Star Lodge - with their little 4-53 Detroits - back down harder than anywhere else, bar none, and the cavitation and vibration is scary, but they do it day in and day out with no damage. Consider it just part of the excitement of backing down on big fish......last June I fought a big marlin at TSL for 4 hours, all of it backing down at full bore....

UV

[Kevin]

Mine are fairly smooth for the most part. At times....randomly they shake rattle and roll in reverse. You just need to remember that props are made to go in one direction......efficiently. We just spin them the other way because we can. Not really sure if it is something to worry about. As long as it runs smooth going forward at all speeds I am happy.

[Vince Luciani]

UV and Kevin,

Thanks for the replies. It's reassuring to hear about your experiences. UV, I would describe my vibration as "scary" at times. But things are smooth as silk in forward so I figured things were OK. Thanks for the "reality check".

Vince

[scot]

A couple thousand horses of Detroit will shake your teeth out and you feel like the whole thing is coming apart....until you put it back in forward, then everything is just fine again.

http://www.youtube.com/watch?v=inmJyTQO ... L&index=44