Yup. A lot of design elements get constrained by the space you have to fit it in. I ripped out the old engine beds and started from scratch. That made sense for my installation. But my boat is about 1/4 the displacement of yours. And mine is heavy for 33'.
Even if you add only a small 90 to the thrust plate it will make a big difference in stiffness. That increases with cube of beam height. So if you double the beam height you increase stiffness by 8x. So even adding a 1/2" flange on the 1/4 plate will increase the stiffness by 8x. Or the if the plate was 1/2 thick it would be 8x stiffer than the 1/4. Maybe that's a simple way to do it.
Dan, that's an excellent drawing! And I get your point strongly. I'm totally in luck that the center of the propeller shaft, at its angle hits nearly exactly at the top of the bed. Unfortunately, the beds are laid in at a 2 degree angle and the propeller shaft is at a 10 degree angle, so the thrust forces are pushing 8 degrees 'upward' on the ways. That's not too much pressure, but it makes me happy the thrust is directly balanced on the bed.
I'd love to do an additional bend (parallel) on the thrust plate. I decided against it for two reasons. First, it can only run a small distance, since I had to cut the part that goes below the ways into a half circle to fit, and second because that piece is relatively cheap so I can replace easily with a more substantial one if actual use demands it. I didn't put bends at the ends (perpendicular) because I felt the bolts would provide sufficient resistance to bending in that direction. But I could certainly be wrong about that!
The boat is fiberglass (balsa wood core), with a fiberglass deck and cockpit. It's stood up well these past 30 years, but it's due for another round of paint, especially some anti-fouling bottom paint... ;-)
:-)
Steve_._,_._,_
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