Transmission Clearance to Hull

[Mike P]

I am currently in the middle of a repower project. In order to get good shaft alignment, I need to have the engine sitting low in the boat, with the corner of the ZF220A only clearing the bottom of the boat by about 3/8″ on the outboard side. Is this too close? Is there a rule of thumb or a standard for this? Appreciate any input. -Mike-

Topic

[Mike P]

Gear to Hull

Tony,

A fiberglass boat, a 37′ SeaRay. The stringers looked wimpy to me so I added 3/4″ of plywood that was glassed in, transom to forward engine room bulkhead. Mounts are 1/2″ aluminum “L” channel with 1/2″ backing to sandwich the top of the stringers, each bracket being 12″ long. I used new Barry mounts I got from Cummins. Sorry, no pictures, my phone dropped and ceased working today!

[Tony Athens]

Gear to hull clearance

No rule of thumb, just “common sense” and good isolators and braces that don’t flex or sag….

The type of boat also makes a difference as to hull flex.. If a steel hull with rigid mounts traveling at 8 Kts vs. a 25ft Farallon that cruises at 23Kts

GOT some pics of all the components as to the mounting?

How thick is the hull in that area? An East Coast type hull in those areas is usually very stiff and thick due to the rounded keel.

Tony

[Author]

Replies