shaft strut

[bobbysky]

2002 23v

At the end of this year I'm going to be pulling my engine so I can change the gear ratio in my v-drive to the current 1:1.46 gear ratio. The problem I'm thinking about right now is that my strut was designed for a 13" prop, therefore if I want to upgrade to the 14.25 x 14 prop I will not have clearance.

Therefore I'm trying to find out what the right shaft strut to get so that I can run the bigger prop. I know that my boat had the option to have a gear reduced v-drive therefore I know a strut must have been available at the time to accommodate a larger prop?

[Moki]

Just curious, why do you want to change the transmission ratio? Will it gear higher for speed or lower for more torque. I am assuming that your current ratio is the same as mine 1:1?

[bobbysky]

i'm changing it for more torque. Then I can put on a bigger prop and it will help with fuel economy, holding speed with the perfect pass, and low end when pulling my loaded boat up.

[Moki]

Got it. I assume that you have already played around with changing the prop pitch.

I am assuming that new transmission will not change your shaft angle, so you will have to go with a longer shaft to get the prop further away from hull. Not to be too simplistic, but can you hold in place the 14 inch prop on your current shaft to the same clearance as your 13 inch prop and then measure the difference to get the correct length?

[bobbysky]

not really any room for a longer shaft. Apparently in our boats age, they had a tige 15 and a tige 16. Mine is the 15 which I'm assuming is a 15 degree angle. Then in 05 they came out with a 16 deep, which is what I think I need. Hopefully there is enough room to adjust the angle of the engine to make it line up with the new deep 16.

[Moki]

You are way more ambitious than me. (and more knowledgeable on transmissions ) You may want to try PM'ing Dom, KKO, or SBFAN. Good luck with your project and keep us updated

[dogbert]

I'm with Moki on this one. You can get way better results by just down-pitching the prop if you plan to run a lot of weight. I get really good fuel consumption just going from a 13 pitch to an 11 pitch prop. ACME's new line of props (especially the 3-bladed kind) have a significantly more surface area than most props.

The problem you will have with a different strut is shaft alignment. I'd talk to the guys at ACME and see what they recommend for your boat.