Inboard engine installation – Template for （内侧发动机安装模板）.pdf

Inboard engine installation – Template for engine beds (This tutorial is excerpted from our shop manual “Plywood Cored Composite Boat Construction”. The manual covers the other parts of the inboard engine installation including the drive train, shaft, cutlass bearings, shaft seals, struts and much more.) Inboard engines are mounted on engine beds aligned with the shaft. The engine beds can be solid wood girders, laminated wood or metal brackets bolted to stringers. This tutorial describes an easy and accurate method to build those engine beds. To obtain the dimensions for the engine beds, we could hang the whole engine somewhere in the boat move it around until if fits and line up then take dimensions for the engine beds. With a 1,000 lbs or heavier engine, this procedure is not practical. A better method is to make a light plywood mock up of the engine, line up that engine template” with the shaft and measure everything from there. That template is easy build and much more practical. Outline: This is a typical plywood engine template: The flat piece of plywood represents the engine with transmission in plan view (from above). In the rear, the template is fitted with a round circle of plywood representing the shaft coupling transmission side. On the front of the template, there is a small piece of wood similar to a gun sight. The line going from the sight to the middle of the coupling is the boats shaft axis. We will pull a steel line (fishing line) from the front sight, through a hole in the middle of the coupling all the way through the stern tube to align all drive train components, engine included. On each side of the plywood template, small blocks of wood represent the engine rubber mounts. For a small engine (less than 100 HP) we make the engine mounts 3.5 long, 2 wide and 1.5 high. That is the section of 2x4. Cut 4 slices 2 wide and you have your mounts. Coupling and mounts must be accurately fastened to the plywood templ