How to Spin Them
#12
VIP Member

Joined: Nov 2002
Posts: 4,176
Likes: 333
From: ankeny,ia.
#13
bigfarmer,
I Love your AVATAR pic! don't know why but it brings back old testing fly by brain pics to mind!!!!
kragar, thrust is less related to the transom when rotating inward.
JT, yes positive trim will direct the thrust below the transom....................
Brett
I Love your AVATAR pic! don't know why but it brings back old testing fly by brain pics to mind!!!!
kragar, thrust is less related to the transom when rotating inward.
JT, yes positive trim will direct the thrust below the transom....................
Brett
__________________
Brett Anderson / BBLADES Professional Propellers
920-295-4435 http://www.bblades.com/
[email protected]
Brett Anderson / BBLADES Professional Propellers
920-295-4435 http://www.bblades.com/
[email protected]
#14
When you rotate in, the effects oppose each other. With the relatively small diameter props, with comparatively deep immersion we use, the prop walk effect is small.
I am spinning my Mercury Racing 4-blade cleavers inboard, and it pivots just fine. It probably pivots slower than it would going outboard, but who cares, I dock only once or twice per outing, and my previous boat was a single, so any additional maneuverability is just a bonus.
The boat will porpoise in the 60mph range, but you can stop it with the tabs. If I was set up to spend a lot of time running in the 60's, I'd probably consider turning them out. If you have the power, and are going to spend most of your time at higher speeds where you need the bow lift, turn them in.
#15
With props spinning outboard, when you oppose the engines to pivot, the prop-walk combines with the moment created by the thrust. I.e., you put the stbd in forward and the port in reverse, both props are spinning to starboard, which causes both props to walk to stbd, and the torque is twisting you to starboard also.
When you rotate in, the effects oppose each other. With the relatively small diameter props, with comparatively deep immersion we use, the prop walk effect is small.
I am spinning my Mercury Racing 4-blade cleavers inboard, and it pivots just fine. It probably pivots slower than it would going outboard, but who cares, I dock only once or twice per outing, and my previous boat was a single, so any additional maneuverability is just a bonus.
The boat will porpoise in the 60mph range, but you can stop it with the tabs. If I was set up to spend a lot of time running in the 60's, I'd probably consider turning them out. If you have the power, and are going to spend most of your time at higher speeds where you need the bow lift, turn them in.
When you rotate in, the effects oppose each other. With the relatively small diameter props, with comparatively deep immersion we use, the prop walk effect is small.
I am spinning my Mercury Racing 4-blade cleavers inboard, and it pivots just fine. It probably pivots slower than it would going outboard, but who cares, I dock only once or twice per outing, and my previous boat was a single, so any additional maneuverability is just a bonus.
The boat will porpoise in the 60mph range, but you can stop it with the tabs. If I was set up to spend a lot of time running in the 60's, I'd probably consider turning them out. If you have the power, and are going to spend most of your time at higher speeds where you need the bow lift, turn them in.
#16
Registered

Joined: May 2009
Posts: 3,895
Likes: 124
From: Chicago, IL; Onekama, MI
I'm going to try spinning my hydromotives in one I get my engines back in my Formula. Spinning out, my boat ran very flat so if I can gain a little bow lift by spinning in would be nice.



