OUTRAGE 25 CUDDY Sterndrive

A conversation among Whalers
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Joined: Sat Jan 05, 2019 8:44 am

OUTRAGE 25 CUDDY Sterndrive

Postby Tesoro » Fri Jan 11, 2019 10:10 pm

I have a really bad case of Whaler-itis right now. I have had eight classics over the years from 13 to 25-feet.

There is a 1986 Outrage 25 Cuddy with a Volvo-Penta DuoProp 330-HP sterndrive for sale locally in good condition. The price is manageable at [$15,000], and I could use that hull for a ruff-n-tuff fishing boat where I live on the [O]regon coast. I plan on leaving the boat moored in the ocean so the outdrive would be in a hot harbor.

I know everything about outboard engines but nothing about sterndrives, and I have never had one.

Can anyone who knows about the performance of [an OUTRAGE 25 CUDDY with a Volvo-Penta DuoProp 330-HP stendrive] reply to this post with comments and caveats.


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Re: Advice needed - stern drive outrage

Postby frontier » Sat Jan 12, 2019 9:10 am

According to the "Boston Whaler Boat Prices and Specifications" guide dated February 1, 1986, Outrage 25' Cuddy, and under "engine options":

STERN DRIVE MODELS--The standard stern drive is a Mercruiser 260 with freshwater cooling, power-assisted steering, engine well pump and blower.

Weight listed with that set-up is 4,470 lbs. No other engines or brands are listed as factory options.

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Re: OUTRAGE 25 CUDDY Sterndrive

Postby jimh » Sat Jan 12, 2019 10:15 am

Sterndrive power is very popular in the Great Lakes, but not so popular in saltwater. This schism is probably because many sterndrive engines are cooled with raw seawater. In saltwater the seawater cooling tends to cause corrosion of the cooling system, particularly the exhaust manifolds, whereas in freshwater this problem is greatly reduced. Some sterndrives use a closed freshwater cooling system and a heat exchanger to the seawater.

There is a humorous and sarcastic observation about the real purpose of a sterndrive: to be a mechanic's annuity.

In regard to the performance of an OUTRAGE 25 CUDDY with a 330-HP sterndrive: the Volvo-Penta DuoProp drive is generally an efficient drive system, although the propeller set is expensive. Performance predictions would be similar with outboard engine power at the same weight on that hull. Using the Crouch method, I would expect the top speed potential to be

LBS= 5,500 (for weight I just added 1,000-lbs to the figure given above for the dry hull weight to allow for fuel, crew, and gear)
HP = 330 (I assume this is the power at the propeller shaft)
HULL CONSTANT = 180 (this is a well-know value for classic Boston Whaler moderate V-hull boats like an OUTRAGE)

Predicted top speed according to the Crouch method is then

MPH = 44

If the power is not rated at the propeller shaft, and if the boat were more heavily loaded, the performance would decrease. Here is another analysis

LBS= 5,700
HP = 300
MPH = 41

In either case, the top speed is likely to be very sufficient for use in the open ocean. I don't think you will be dashing around at more than 40-MPH too often.

As for fuel consumption, I would assume the gasoline engine may have a brake specific fuel consumption (BSFC) of about 0.55-lbs/HP-hour at maximum throttle. At full throttle and making 330-HP, the engine would then consume 182-lbs of fuel per hour. If gasoline fuel at a density of 6.25-lbs/gallon is consumed, then about 29-GPH is the fuel flow rate. If making 44-MPH, then fuel economy would be 44-MPH/29-GPH for 1.5-MPG. The actual economy will depend on the engine's actual BSFC, the propeller and drive efficiency, and other factors. But I would expect 1.5-MPG to be the worst likely fuel economy; it may be closer to 2-MPG. Note all my distances are in reference to statute miles. If you prefer units of nautical miles, you can convert them with a 1.1515:1 factor. At slow engine speeds (as used when angling) the engne BSFC is probably improved, and MPG would likely be better than older two-stroke-power-cycle carburetor outboard engines could produce.

If not familiar with these estimates, I explain the Crouch method in another article. Use of brake specific fuel consumption (BSFC) is a standard method of assessing engine performance. A Wikipedia article may offer more insight on brake specific fuel consumption.

The presence of that T-Top will tend to reduce performance from these calculations. Also, I don't think Boston Whaler ever offered a factory option of a T-Top, so the presumption I would make is that T-Top on this boat was added after it left the factory.

Some other comments:

--the closed transom of the sterndrive OUTRAGE would be advantageous in my opinion for use in the open ocean when angling, as in a following sea you would not be taking any waves over the transom as will occur with a notched transom boat trolling slowly downwind in some seas;

--the greatest liability with a sterndrive is the rubber bellows that keeps the sea from entering the boat at the transom via the large hole made in the transom for the sterndrive mechanism. Any puncture of the bellows brings seawater aboard. With the vast reserve floatation of a classic Boston Whaler 25-foot hull, this concern is somewhat lessened, but the integrity of the bellows is paramount to staying afloat;

--this particular boat has the Super Console, which some think is an advantage compared to the much narrower standard console; others think the console is too wide and impedes movement fore and aft in the cockpit. It is really a matter of personal preference.

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Re: OUTRAGE 25 CUDDY Sterndrive

Postby Jefecinco » Sat Jan 12, 2019 10:33 am

Having owned and used a stern drive boat for 20 years I can't recommend the option for sea water use, particular for ocean mooring. Unlike an outboard engine a stern drive lower unit can't be tilted completely out of the water. No matter what you do the aluminum stern drive leg will corrode or waste over time in sea water.

The rubber bellows will fail unless changed periodically. For a moored boat I would replace the bellows annually.

Ownership of a Volvo-Penta drive can be a problem due to a much smaller dealer network. Parts for the Volvo-Penta units can be much more expensive than Mercruiser parts.

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Re: OUTRAGE 25 CUDDY Sterndrive

Postby Tesoro » Sat Jan 12, 2019 11:44 am

Thanks for the inputs! I have to follow my gut and needed someone to help break my fever...in the late 80's there were no 'great' outboards made that didnt suck fuel and sound like jet engines. And their engine longevity was on the low end of the scale. SO if an inboard at that time had been such a great alternative then we would have seen them everywhere in whalers and not just as a rarity as we now do.
However I can see the rich n famous having some summer fun with their quiet running whalers hanging on slings at their northern fresh water lake homes...thus the outdrive option I guess.

I assumed that the whaler in question had a heat exchanger with fresh water cooling. However having an alloy outdrive submerged in a salt water boat basin with excessive stray current is prob not the best idea. Anodes dont protect against that. last summer I had a 23 ft aluminum boat ( never again) moored for 5 weeks in that harbor and when I hauled out one side of the hull looked like it had been shot with bird shot. Little black dots everywhere where the outer layer of the alum had been compromised. The beginning of the end of that hull if I had continued to keep it moored.

Also I was just sent a pic of the engine and the compartment is flush with the deck. There is no dam around it to funnel rain water or other out the drain holes. There is a huge void in the stern that can fill up with water so one is at the mercy of pumps. Not for me!

So I will continue my quest to find a std outrage with whaler drive. My favorite power is the small block hpdi and can still find low hour fresh water versions if patient. I am not sure if 4 strokes are too heavy or not for that configuration. But they are too expensive and overly complicated, that I know.