bow lift, as a fuction of the prop pitch?

31scorpion

Cadet
Joined
Mar 6, 2004
Messages
15
Hey Hey Quick question<br />31 foot boat, I have 23 pitch mirages counter rotating, boat at high speed seems to "lay flat" and shifts side to side, but not tilting back and forth, flat side to side in the transom like on ice.(above 50mph) Q: If I lower the prop pitch does that alone, provide the engines more leverage to trim the boat to a desired angle (bow up)? any other suggestions.....of course thanks for the help!
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
71,088
Re: bow lift, as a fuction of the prop pitch?

Pitch, as a function has little to do with Bow-Rise..........<br />That's done with Blade Style.......<br />Round-eared Blades, with Longer Rake will provide Bowlift.....<br /><br />I'm not sure Where the mirages fit in......
 

Winger Ed.

Chief Petty Officer
Joined
Mar 24, 2004
Messages
649
Re: bow lift, as a fuction of the prop pitch?

Sounds like 'chine walk'. From what I've heard, its just inherant in some boats. What makes them handle & ride well at one speed-- slow and medium for example often makes them a bit squirrely at high speed.<br /><br />As far as the tilt, if you've got full inboards, about all you can do is transfer weight around to change the bow angle. Trim tabs will force the bow down, but they won't make it come up any more than it already can. If you've got outboards or inboard/outdrives- just raise the angle of them a little at a time to bring the bow up.<br /><br /><br />Lowering the prop pitch will let it come out of the hole and accelerate faster, but then again it will also probably let the engines overspeed for a reduced speed on the top end. (the same effect as putting smaller or shorter tires on a car.)<br /><br />If its getting up that fast, and doesn't leave much of a wake, its probably set pretty close to perfect unless you've added a bunch of weight to the front.
 
Top