I have not done this conversion, but I see that it has been done (Google).
I am presently converting two VW TDI engines for marine
use. The difference is that I have purchased conversion kits from Pathfinder, and have parts
availability from VW's "marine" division.
Don't let the naysayers talk you out of it.
Also, keep the limiting speed governor. Some folks on this forum seem to think that a marine engine
uses a variable speed governor, which isn't the case.
Get your cooling
system sorted. Get a belhousing to fit, and figure out the electronics
for the injection system. I'm assuming it's a common rail diesel
, or at least electronically controlled. If not, things are much easier.
I look forward to hearing about your solutions to this conversion. It's a fairly compact engine
, though quite a bit wider than most, which may cause issues in a smaller monohull installation
A good place to start reading might be here: http://www.xcceleration.com/marine.html
They do Gas engines, but the conversion would be similar, and some of the parts
may be interchangeable.