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Old 09-17-2013, 04:06 PM   #21
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Originally Posted by Capt Kangeroo View Post
Why they would put so much unneeded horsepower in vessels that were clearly designed / intended for slow cruising simply mystifies me.
I don't think that the builders intended for the boats to be "slow cruised." As has been pointed out by "Skid", these were very different times in boat building. Some buyers wanted slow economical boats & others wanted to get to their destinations a little faster. Rather than build two or three different models, Semi displacement hulls were decided on and the size of the engine was left up to the buyer. Fuel was dirt cheap as were boats built in the Orient and life was great!

No, the builders knew exactly what they were doing and we enjoy the fruits of their labors to this very day.
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Old 09-17-2013, 04:46 PM   #22
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Originally Posted by Capt Kangeroo View Post
Why they would put so much unneeded horsepower in vessels that were clearly designed / intended for slow cruising simply mystifies me.



Unneeded horsepower? What's that?
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Old 09-17-2013, 05:44 PM   #23
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Originally Posted by Tacomasailor View Post
Hello How does one operate a pair of overly powerful engines at economical cruise speed when a single engine can provide all the needed power at a low RPM? The DeFever 61 needs only 73 HP at the prop to move at 8.7 knots which can be delivered by ONE engine at 1500 RPM.
Provided the PO did a good job of maintenance, those engines have lots of life left in them. You need not worry about the engines gumming up if you run them slow provided the oil temperatures are minimally 180 or so when cruising at about 8 to 8.5 knots.

For sure the Cat maintenance schedule needs attention, if the PO shirked his obligations because he was cheap or lazy, be prepared to spend an easy $8K having Cat do the required work, which is much more than an oil and filter change.

BTW, describe the DeFever a bit more, I 'm familiar with these vessels and could maybe make a suggestion or two. Feel free to PM me.
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Old 09-18-2013, 07:07 AM   #24
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>Why they would put so much unneeded horsepower in vessels that were clearly designed / intended for slow cruising simply mystifies me.<

There are at least 3 reasons for BIG engines in boats that would be more efficient with more rational sized engines.

1, the advert dept , selling a big boat (35-55ft)with less advertised power than a 20ft fish boat requires knowledgable purchasers,

2, Purpose built Marine engines are rare and expensive , car , taxi or yard implement engines are made in high volume so are cheap when marinized.

The advertised HP of most non industrial converted engines is their auto power rating , peak for 5 min if that.

Since the actual power required is modest for a displacement boat the claimed 120HP engine running 30-40HP does little harm from under loading.

Look for the 24/7 HP rating to judge a marine or industrial engine, for an offshore boat.
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