If you are changing out a relatively new engine (10 years or so old) you should have no issues and extra expense going from one manufacturers engine to another. Remember that all engine manufacturers want the same customers and therefore build to a basic standard so that they can try to sell to the same boatbuilders. The engine needs to fit on the same engine beds (bearers) and to line up with the shaft. You expect to have to change some exhaust
hose and fuel
hose but other than drilling and tapping some new threads for flexible mounts, the change from Volvo to Yanmar or Beta Marine
or Westerbeke should
be relatively simple. You must measure carefully to make sure that one part of the new engine doesnt interfere with the rest of the engine compartment.
Generally the engine company that gives the boatbuilder
the best price
is the one that sells the most engines to that boat builder
. They then make up their profit on parts
sales over the years.
If you are replacing an older engine you will find many different mount variations as the companies that built engines between 1950 and about 1985 all tried to make engines that could only be replaced by their own strange mount arrangements. These companies are largely still in business but now build to certain standards. An example is a modern 20HP diesel
should be on 14.5" centers port to stbd and the shaft should be at the same height as the engine beds. Remember that the mechanic that you use will have a preferance for the engines that he sells.
The above all refers to standard engines. Saildrives are sometimes a bit harder but your research
now, will pay dividends later. The 130 S saildrive is the ZF SD10 which is used by a number of different engine companies including Beta Marine
I must point out that I am in the replacement engine business as the distributor for Beta Marine
in the US.