Westerbeke - Perkins
The Westerbeke 4-107 (aka W40) is a Perkins block that was marinized by Westerbeke. In the early days the 4-107 was rated at 37HP, later upped to 40HP and finally to 50 HP as measuring systems changed. The 4-107 was updated by Perkins to the 4-108. The biggest change was the switch from wet cylinder liners to dry. Most of the other engine components are the same. When it comes to the marinizing parts, there is a lot of difference between the Perkins and the Westerbeke. If you are considering putting on of these in your Hunter 34 you might want to do a little checking. The biggest engine used by Hunter was the Yanmar 3GM 30, rated at 27HP. The 4-108 by Perkins is rated at 50HP. Aside from possibly not having enough physical space for the engine you will be grossly overpowered. Granted you don't have to use it all but it won't make your boat go any faster. You will also be doubling the weight in the engine room. (286# to 626#) The Hunter 34 started production in 1983. Your present Yanmar is less than 18 years old. Unless you totally blew it up, it is still good, or at least rebuildable.
