At 02:50 8/8/2000, Helmut Zeidler wrote:
>David,
>
>Thanks for your introduction to marine engines.
> From my experience with VW SDI and TDI engines
>I like to give you some more details to answer
>your statements.

Thanks, Helmut, I'll check it out.  I must say that marine service is like
industrial or powerplant service -- extremely severe duty.  It will be
surprising to me if VW rate these engines the same as automotive engines,
and if they do I will be very doubtful of the engine's endurance and would
be cautious about buying one for marine use.  Concerning the weight, I
overstated my meaning -- as you say, the specific additional components are
not very heavy; but if the engine is derated -- for example, I am
acquainted with a particular boat having a 300hp Caterpillar Diesel which
is derated to 200hp for marine use -- 33% less power but the same
weight.  I don't know the weight but would estimate it at easily 300 kg
with reduction gear.  I believe it is a 2-cycle engine with Roots
blower.  It is an inline 6, unknown displacement, redline somewhere around
2500 rpm I believe.  Normal use around 1500 rpm in this boat,  swinging a
four-bladed propeller of about 110mm diameter and 130mm pitch with 2.5:1
reduction.  The boat, incidentally, is about 18 meters long and 39,000kg
displacement, cruises around 9 knots.  A faster boat would not need the
great reduction and very large propeller.  I would expect 3000-4000 hours
from this engine before overhaul (but I'm guessing on that).

A racing engine will of course be entirely different, everything is
sacrificed to power.

david
David Beierl - Providence, RI
  http://pws.prserv.net/synergy/Vanagon/
'84 Westy "Dutiful Passage"
'85 GL "Poor Relation"