Steve wrote:
If we are talking about the original VW that came out in the early '80s, the
25 HP limit is probably true.

Been there done that.. That engine is just a converted Rabbit gas engine. I
think I remember that it only produced 40HP as a diesel.

Actually it was 50 hp, naturally aspirated.

I blew-up two of
them in my '82 Vanigon. Never got more than 20,000 out of either engine.
Couldn't handle Calif. Freeway (80mph) speeds for sustained periods (hours).
These engines didn't have a tach but I suspect it was turning about 3k at 80
mph.

Bad guess! Depending on tire size, 80mph in a Diesel Vanagon
(lower final drive ratio than the gas engine models) is about
4600rpm. The engine redline is 4200 rpm.

Hole in the block both times. Too many broken pieces to tell which
broke first.

Cruising long-term at 400+rpm above redline tends to do that :-)

A VW diesel in a sailboat would probably last forever, running
2500rpm, but by the time you 'marinized' it, it would probably be
more expensive (with more weight/hp) than a new marine engine.

Keith Hughes