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There has been a major change in my ideas towards engine and drive train since I started this project. Originally I was going with a Yanmar Saildrive because it is easy to install and is very quiet. Then John pointed out that the zinc needs to be changed out every six months and cannot be neglected because the saildrive is aluminum. The zinc is in front of the prop and the prop has to be pulled which means a haul out every six months. That may be fine for you Yankees that winter your boats on dry land, but down here in Georgia, we sail all year long and can get two years out of a good bottom job.
Three extra haul outs every two years can add up to some big bucks so I changed to a Yanmar 4JH3E with a standard shaft. To eliminate engine vibration being transmitted down the shaft to the hull, I chose an AquaDrive CV joint shaft coupling and a thrust bearing. At the same Time I decided on a CV joint attachment for the front of the engine to take the side loads of the big alternator off of the engine bearings.
The engine stringers are laminated up from white cedar and mahogany. The step is for the front end power takeoff and the alternator mount.
After carefully mounting the engine stringers in place, I was fully expecting to have a major job with the hand plane aligning the tops to the exact 5 degree incline John called for. I cut up some scrap plywood to make a pair of templates for the engine base and drilled a hole in each to represent the centerline of the transmission shaft.
I set up my laser level on the center line and inclined it so that the beam passed through both holes. Bingo! 5 degrees exactly! The spot where the beam fell on the hull was where the shaft log would go. With one minor complication.
The shaft was to be offset 1.5 degrees to port so that it would clear the rudder should the need arise to pull it.
With string, tacks and a chalk line I laid out the line of the shaft beginning the angle at the center position of the CV joint coupling.
I adjusted the position of the laser level slightly to Starboard so that the beam was on the shaft line and mounted a 1/2" ship auger in the biggest drill I have. The back of the D handle was exactly in line with the chuck so I placed the drill bit on the laser spot and positioned the drill so that the spot shined on the center of the D handle, crossed my fingers and punched the first of many holes in my precious hull.
When I removed the drill, the laser passed cleanly through the hole. I crawled under the hull and located the position of the cutlass bearing. The plans called for 232 mm clearance from the hull. The beam measured 234 mm! Compensating errors are a wonderful thing!
Now Supremely confident, I turned down the end of a length of 1/2" drill rod to fit in a 2 1/2" hole saw and after a half hour of drilling and chiseling, had an almost perfect oval gash in my dear hull.
The Centrec shaft log fit just right.The shaft log went in with very little effort and was aligned with the laser level. I wedged a 2" dowel into the log to hold it in place while I tabbed it in with several layers of biaxial glass. The only hard part was crawling under the hull to fair the hole. I must be getting old. I hate working over my head and the Centrum Sliver didn't help at all.
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The Aqua Drive is an interesting device. It is basically a very short CV joint axle and a thrust bearing. The object is to keep all the engine vibration away from the hull and the prop thrust away from the engine. 
The thrust bearing requires a substantial bracket to take the thrust to the hull. 
The prop strut was supplied by Edson. John went over the available sizes and bearing angles of various stock production boat struts and arranged for Edson to make this one up. It is a substantial chunk of bronze that fits up through a slot in the hull. 2" thick brackets were glassed to either side to provide lateral support and the whole thing was encased in an obscene amount of glass. (You can see the copper tape for the SSB ground running down either side of the strut.) .
