|
|
Posts: 192
| I have a 150 HP Optimax and I run a stainless prop. This summer I am going up to LOTW for a week. Last time I did this about 10 years ago, at the advice of others I put an aluminum prop on for the trip. As luck would have it, I did hit a rock and totally destroyed the prop. I put my stainless back on and finished up the trip.
After that incident I had numerous issues with my motor, although I never attributed them 100% to that rock collision. Might have contributed, might not. I really can't say for sure.
Since that trip I've read that putting on an aluminum prop really isn't a good idea and may do more harm than good if you hit something. I think the theory is the aluminum prop actually absorbs energy as it collapses and transfers that energy into the engine, causing more damage. I’ve also read that hitting a rock with the stronger / stiffer stainless prop will cause the Flo-Torq Hub plastic sleeve to fail but cause less damage overall.
So, I'm trying to confirm that and see what everyone suggests besides not running into rocks. Right now I'm leaning to taking along a spare Flo-Torq Hub kit and maybe getting an aluminum prop to take along as a spare but not putting it on.
Map chips have improved greatly since my last trip, so hoping that helps also.
Edited by LarryO 4/13/2014 9:50 AM
| |
| | |
Location: Waukesha, WI, USA | The theory is that the aluminum prop is the sacrificial lamb. Hit a rock and it is destroyed but little to no lower unit damage. Stainless holds up better but transfer eps the energy to lower unit. | |
| | |
Posts: 3508
Location: Elk River, Minnesota | Hiya. In both cases If you are at speed, neither prop will save your lower unit. In a slow speed strike, the aluminum will break, which is a good thing. That beak is a transfer if energy away from the lower unit, which helps save the potential damage of the lower unit. With a steel prop, the prop will most likely not break...it will bend some. In a slow speed strike, that energy will transfer more to the lower unit just because of the strength of the steel. What will give is the shaft at the lower unit, the gearing inside, and potentially the lower unit itself.
In either case, I don't think the hub is a safe bet to fail, although I could see that as being sacrificial in a slow speed strike. It would be the first thing replaced in a hit, though if no apparent damage to the motor existed.
High speed, nothing will save the lower unit.
Steve | |
| |
|
Aluminum vs. Stainless Props