Help choosing a new prop for me E-tec

[Markyboyo]

I'm thinking of getting an additional prop for heavy loads and tubing/skiing.
Boat is a 5.5m humber destroyer with an 115 XL E-tec (V6 gearbox) turning a 14.75*19 Viper prop.
I see 39kn at about 5800rpm 2 up with a full tank but if I put 6 or more people in the boat I struggle to get much past 5100. I never really use WOT heavily loaded but obviously the engine is lugging.

I'm thinking of getting a 4 blade alu prop from steel developments for heavy load use and can't decide between the 14.75*15" (most likely) or a 17". I think 15" really.

Any experience thoughts would be good

[Simon B]

Try Steel Developments, I've had a few props from them over the years, they'll give reasonable advice. We got quite a good four blader from them for our dive boat years ago. Really improved the performance.

[Chris]

Originally Posted by Markyboyo

I'm thinking of getting an additional prop for heavy loads and tubing/skiing.
Boat is a 5.5m humber destroyer with an 115 XL E-tec (V6 gearbox) turning a 14.75*19 Viper prop.
I see 39kn at about 5800rpm 2 up with a full tank but if I put 6 or more people in the boat I struggle to get much past 5100. I never really use WOT heavily loaded but obviously the engine is lugging.

I'm thinking of getting a 4 blade alu prop from steel developments for heavy load use and can't decide between the 14.75*15" (most likely) or a 17". I think 15" really.

Any experience thoughts would be good

Ideally you set the prop up so that the engine achieves its ideal RPM when the boat is loaded as per its normal use.

If you occasionally run with a heavy load then it won't do any harm especially if you don't try to run flat out. However if you regularly run with 6 up then this really should be the load that the prop is set up for. Changing props is clearly an option and if you are heavily loaded then a four blader would make sense.

I think the Evinrude Rogue four blader would be worth looking at, 15" or possibly 17... If you speak to Mike Vincent at Southcoast Marine he has loads of props in stock and is normally happy to let people test them before buying.

[Markyboyo]

I've got the V6 gearbox on the XL shaft so I don't think I can fit a Rogue Chris. I'd be looking at a Rebel or cyclone but BRP props are rather dear but I have read more than once that they are made by solas.

For most of my running the Viper I have is fine, I'm mostly 2 up but when I go skiing/tubing I tend to be 4 up + one in the water. The Viper also feels like it falls off the plane much sooner than it should so I hope a 4 blade will improve this too.

I think I'm going to throw caution to the wind and order up the one from Steel developments, I can have 3 for less than the price of 1 stainless BRP prop

[GordyP]

I have a 17" viper that would fit if it's any use?

[Pikey Dave]

Originally Posted by Markyboyo

I've got the V6 gearbox on the XL shaft so I don't think I can fit a Rogue Chris. I'd be looking at a Rebel or cyclone but BRP props are rather dear but I have read more than once that they are made by solas.

For most of my running the Viper I have is fine, I'm mostly 2 up but when I go skiing/tubing I tend to be 4 up + one in the water. The Viper also feels like it falls off the plane much sooner than it should so I hope a 4 blade will improve this too.

I think I'm going to throw caution to the wind and order up the one from Steel developments, I can have 3 for less than the price of 1 stainless BRP prop

the problem with ally props is that you will drop a couple of hundred rpm for no gain over a similar stainless prop. I.E you will need to drop more pitch than necessary, just because it's ally, so there's not much net gain. Take a look at the mercury rev4, this will give more grip & more load carrying capacity than the Viper, which imho isn't a particularly good prop.