Re: re Diesel Outboards
Hi David,
Your question has several parts: Why Diesel, and Why Big Ugly Heavy
outboard?
Mostly, people either are for or against diesel, without much hope of
conversion. The main benefits are reliability (lack of exterior
ignition or carburation, maybe even no "black box" brains), economy
(reduced fuel consumption, more range), and low RPM torque. The smell
of the exhaust is an acquired taste, and is variable with loading,
least when the motor is happy. Wet exhaust helps. To me it brings back
the smell memories of fish and Tokyo. I find gas exhaust (even 4 stroke)
noxious, and I believe it is more poisonous by boat/mile.
Big Ugly is harder. Not many tasty choices available here in US because
EPA and NMEA have decided against diesel motors as unsophisticated as
those on a model airplane. Big 'cause the high compression needs a
tough cylinder. Ugly because the lower unit is probably sand cast, and
like most Sino-industrial products few care what it looks like (or
weighs)? Not much incentive to make it lighter or pretty.
Heavy, but for a larger displacement vessel, not unduly so. Probably
about the same as my 70HP Merc, which, swinging its similar 12" prop at
4x the revs *might* do as much real work with about 20x the fuel
consumption. A displacement vessel heavy enough to be unconcerned with
the weight should be heavy enough to absorb the vibration. Maybe 25'+
LOA? Many people (I included) perceive a lower RPM vibration, even
stronger, to be more pleasant (OK less unpleasant) than a higher
frequency one.
I have not owned one of those gizmos, but I have had enough inboard and
outboard gas motors, and for my next (displacement) boat, primary
propulsion will be diesel.
So if you are sold on the Diesel, but not on Big Ugly Heavy, Yanmar
does make 2 very pretty and quiet higher HP models (popular $$$ options
for US Special Services fast attack craft) but you must be creative to
get them:
http://www.yanmar.com.au/marine/d_series/dseries.htm
Jason
Your question has several parts: Why Diesel, and Why Big Ugly Heavy
outboard?
Mostly, people either are for or against diesel, without much hope of
conversion. The main benefits are reliability (lack of exterior
ignition or carburation, maybe even no "black box" brains), economy
(reduced fuel consumption, more range), and low RPM torque. The smell
of the exhaust is an acquired taste, and is variable with loading,
least when the motor is happy. Wet exhaust helps. To me it brings back
the smell memories of fish and Tokyo. I find gas exhaust (even 4 stroke)
noxious, and I believe it is more poisonous by boat/mile.
Big Ugly is harder. Not many tasty choices available here in US because
EPA and NMEA have decided against diesel motors as unsophisticated as
those on a model airplane. Big 'cause the high compression needs a
tough cylinder. Ugly because the lower unit is probably sand cast, and
like most Sino-industrial products few care what it looks like (or
weighs)? Not much incentive to make it lighter or pretty.
Heavy, but for a larger displacement vessel, not unduly so. Probably
about the same as my 70HP Merc, which, swinging its similar 12" prop at
4x the revs *might* do as much real work with about 20x the fuel
consumption. A displacement vessel heavy enough to be unconcerned with
the weight should be heavy enough to absorb the vibration. Maybe 25'+
LOA? Many people (I included) perceive a lower RPM vibration, even
stronger, to be more pleasant (OK less unpleasant) than a higher
frequency one.
I have not owned one of those gizmos, but I have had enough inboard and
outboard gas motors, and for my next (displacement) boat, primary
propulsion will be diesel.
So if you are sold on the Diesel, but not on Big Ugly Heavy, Yanmar
does make 2 very pretty and quiet higher HP models (popular $$$ options
for US Special Services fast attack craft) but you must be creative to
get them:
http://www.yanmar.com.au/marine/d_series/dseries.htm
Jason
--- Inbolger@yahoogroups.com, "daveydimwit" <daveydimwit@y...> wrote:
> I have had a close look at one of these things in pieces. The engine
> and the drive unit are obviously made by two different
> companies(cultures). The engine looks well finished and professional.
> The rest of the drive unit is blacksmith quality made of stainless
> steel, solid as a rock but not finished or polished looking so it
> looks really clunky. The drive section weighs a ton. It does have an
> electric start.
> I have access to a unit that requires one or two parts to get it
> running but I wonder what the benefits are.
> Diesel's stink, are noisy and the single cylinder ones vibrate
> something awful. Their main saving grace is that the fumes don't
explode.
> Seeing this is an outboard and I don't have to worry about the fumes,
> I am asking myself why would I want to put one on my boat?
>
> David
Fumes from a running engine won't explode no matter what the fuel.
The fumes from the raw fuel in the tank(s) are the issue, with gas
they are explosive, with diesel the odds of a fire are remote. Even
with an outboard the tanks are still usually in the bilge, so it still
matters.
Bill H.
The fumes from the raw fuel in the tank(s) are the issue, with gas
they are explosive, with diesel the odds of a fire are remote. Even
with an outboard the tanks are still usually in the bilge, so it still
matters.
Bill H.
> I have had a close look at one of these things in pieces. The engineprofessional.
> and the drive unit are obviously made by two different
> companies(cultures). The engine looks well finished and
> The rest of the drive unit is blacksmith quality made of stainlessexplode.
> steel, solid as a rock but not finished or polished looking so it
> looks really clunky. The drive section weighs a ton. It does have an
> electric start.
> I have access to a unit that requires one or two parts to get it
> running but I wonder what the benefits are.
> Diesel's stink, are noisy and the single cylinder ones vibrate
> something awful. Their main saving grace is that the fumes don't
> Seeing this is an outboard and I don't have to worry about the fumes,
> I am asking myself why would I want to put one on my boat?
>
> David
I have had a close look at one of these things in pieces. The engine
and the drive unit are obviously made by two different
companies(cultures). The engine looks well finished and professional.
The rest of the drive unit is blacksmith quality made of stainless
steel, solid as a rock but not finished or polished looking so it
looks really clunky. The drive section weighs a ton. It does have an
electric start.
I have access to a unit that requires one or two parts to get it
running but I wonder what the benefits are.
Diesel's stink, are noisy and the single cylinder ones vibrate
something awful. Their main saving grace is that the fumes don't explode.
Seeing this is an outboard and I don't have to worry about the fumes,
I am asking myself why would I want to put one on my boat?
David
and the drive unit are obviously made by two different
companies(cultures). The engine looks well finished and professional.
The rest of the drive unit is blacksmith quality made of stainless
steel, solid as a rock but not finished or polished looking so it
looks really clunky. The drive section weighs a ton. It does have an
electric start.
I have access to a unit that requires one or two parts to get it
running but I wonder what the benefits are.
Diesel's stink, are noisy and the single cylinder ones vibrate
something awful. Their main saving grace is that the fumes don't explode.
Seeing this is an outboard and I don't have to worry about the fumes,
I am asking myself why would I want to put one on my boat?
David