Re: Diesel compared to outboards

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Re: Diesel compared to outboards

Postby Old PDQ Message Board » Mon Apr 26, 2004 6:25 am

Re: Diesel compared to outboards

Posted by Dan Hofmann on April 22, 2003 at 04:43:00:
In Reply to: Diesel compared to outboards posted by Denny DeRanek on April 21,
2003 at 09:31:00:


I have a 6 year old 32 with the gas engines. I think Terry spells out the pro's
and con's quite well. I have one question. I have been out cruising and just
returned but I have never heard of a 20 HP Honda that fit our boats??? Is this
something new?
The decision to go gas says that you save about $15,000 up front on the cost of
the boat. That means that you can by 3 sets of new engines before you go
negative. I have found that after 4 years of a lot of travel, Bahamas twice and
Florida once, The engines either need to be replaced or you must rebuild the
head and clean up the water passages. My starboard engine did last 6 years but I
am now rebuiling it. Port was done 2 years ago

If you are going to live aboard and cruise constantly, the diesel make more
sense. If you are just cruising for 6 months at a time, the gas have a value.

Follow Ups:

Re: Diesel compared to outboards Terry Green 05:07:01 04/22/03 (0)

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Re: Diesel compared to outboards

Posted by Terry Green on April 22, 2003 at 05:07:00:
In Reply to: Re: Diesel compared to outboards posted by Dan Hofmann on April 22,
2003 at 04:43:00:


http://www.honda-marine.com/mod15_20hp.htm
One other disadvantage of outboards= 12amp alternators. I have two 100 amp
Balmars on my Yanmars

Follow Ups:

Re: Diesel compared to outboards

Posted by Terry Green on April 21, 2003 at 11:51:00:
In Reply to: Diesel compared to outboards posted by Denny DeRanek on April 21,
2003 at 09:31:00:


Denny,
We have diesels onboard "Second Wind" Advantages are greater thrust in heavy
weather, greater speed with lower fuel consumption, better spacing for
manuverabilty (in the centers of the hulls), water heating while the starboard
engine is running, and lowered CG. The disadvantages are they are much more
expensive, they take up two large compartments where an outboard setup has
storage, and they are in a tight area making them harder to service. Outboards
are less expensive (you can buy two for less than the cost of one diesel), they
provide adequate thrust (the 20 HP Honda high thrust may be competitive with
diesels), and they are easily serviced by raising the engine into the cockpit

They do require more maintenance, and are subject to cavitation, since they are
mounted above the hulls

I like the diesels, but there are good reason for each

Terry Green/36040

Follow Ups:

Re: Diesel compared to outboards Roger Pollard 11:42:26 04/26/03 (0)
Re: Diesel compared to outboards Dan Hofmann 04:01:41 04/26/03 (0)
Re: Diesel compared to outboards Thomas Gillispie 05:14:03 04/22/03 (0)

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Re: Diesel compared to outboards

Posted by Roger Pollard on April 26, 2003 at 11:42:00:
In Reply to: Re: Diesel compared to outboards posted by Terry Green on April 21,
2003 at 11:51:00:


The Honda BF20 is not an option because it is too short. The Honda BF15,
however, is available in a 27" extra long shaft. It is a redesigned engine for
2003.

Follow Ups:

Re: Diesel compared to outboards

Posted by Dan Hofmann on April 26, 2003 at 04:01:00:
In Reply to: Re: Diesel compared to outboards posted by Terry Green on April 21,
2003 at 11:51:00:


I completely forgot about that weight problem. I have cruised with 2 36's and
seen the exact thing he is talking about, the Diesel is much lower in the water

This would also effect bridge deck clearance

I had also raised the question about the Honda. I looked at the spec's and it
apears to be 4 inches shorter. If you are worried about cavitation, that would
be an issue.

Follow Ups:

Re: Diesel compared to outboards

Posted by Thomas Gillispie on April 22, 2003 at 05:14:00:
In Reply to: Re: Diesel compared to outboards posted by Terry Green on April 21,
2003 at 11:51:00:


Terry made some good points, and we considered the same line of thinking
initially, but I have to say I am glad we went with the gas engines instead of
the diesels. If I am not mistaken, we actually passed on Terry's boat and bought
the one next to it with the outboards instead

First, when the two boats were sitting side by side, the gas model sat a full 3
inches higher out of the water on the back end than did the diesel model. I
assume this is because the diesels are heavier, or they sit further back in the
hulls, but in any case, our bottom step is atleast two inches out of the water
in flat calm

Second, when we sail with our friends on a similar PDQ 36 that has the the
diesels, we are typically a half knot faster with the same sail configuration. I
know from forgetting to retract the outboards under sail, that they cost us
about 3/4 knot in 10 - 12 knots true, so I am sure the sail legs on the diesls
are dragging pretty good

Our biggest concern with the gas powered version was charging requirements. The
diesels definately have the advantage here as they can both have alternators

The little alternators on the outboards are pretty aenemic with thier 4 - 5 amp
output. We address charging issues on board with 2 100watt solar panels, a 5
blade wind turbine, and lastly a 26 lb. Honda 1000W gas generator

The longest we have stayed out was for 3 weeks and we were easily able to
maintain our battery banks with a combination of the above. With refrigeration
and other equipment needs, I find that we use 40 - 45 amps per 24 hours. With
summer sun, we have been able to make it 9 consecutive days at those rates on
solar and wind alone

There both great boats, just my two cents worth

Tom

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