1992 27 OFFSHORE Twin E-TEC 250-HP Engines

Optimizing the performance of Boston Whaler boats
JanaSea27OS
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Joined: Mon Dec 31, 2018 5:29 pm

1992 27 OFFSHORE Twin E-TEC 250-HP Engines

Postby JanaSea27OS » Wed Jan 23, 2019 4:23 pm

Here is data about the power and performance of my 1992 27 OFFSHORE--I hope it will be of interest. I know I can learn from the experience and knowledge of others on this forum. I admit up front I am no expert. I have some experience with the hull and power.

My 1992 27 OFFSHORE is powered by twin 2008 E-TEC 250-HP engines. I use it exclusively in fishing the coastal areas off Newport, Oregon, which gets its share of rough ocean conditions. The twin E-TEC 250-HP engines provide enough low-end torque to get up on plane very quickly, even with a load.
The hull design basically eats up our afternoon wind chop, and gives a smooth dry ride.

I have owned [the 1992 27 OFFSHORE] for five years and put 1,800 hours on the 2008 E-TEC engines. With regular maintenance and a great technician, they purr.

On a nice ocean with two-foot wind waves, two-foot swell, eight-second period, the 1992 27 OFFSHORE cruises very comfortably at about 22 to 24-nautical-miles-per-hour. The fuel burn is 0.8-gallon per nautical mile to 1-gallon-per-nautical mile.

[Moderator's note: usually fuel economy is stated in distance per volume of fuel, and most commonly in statute miles per US gallon. Converting the unusual data in terms of gallons per nautical mile to more familiar units, gives a more easily understood value. In this case the commonly used value of fuel economy for the boat under discussion would then be 1.15 to 1.44-MPG.--jimh]

Slowing down in steeper seas results in 1.5 to 2 gallon burn at about 12 to 15-nautical-miles-per-hour.

[Moderator's note: the data above is stated ambiguously. We don't know if the 1.5 to 2.0 gallon consumption is per unit of distance or per unit of time. Please clarify--jimh]


Thanks for the opportunity to present this data.

Mr 88
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Joined: Tue Aug 07, 2018 8:17 pm

Re: 1992 27 OFFSHORE Twin E-TEC 250-HP Engines

Postby Mr 88 » Wed Jan 23, 2019 7:13 pm

I wonder how my 1987 27 FC [or Full Cabin] with inboard engines will handle three-foot to four-foot waves?

I operate on Lake Ontario. The waves are usually closely spaced, in three-to-four-second period.

I picked up my 1987 27 Full Cabin in the fall and never conducted a sea trial. I would assume its hull design [is] the same as [the 27 OFFSHORE]. The 27 FC was made from 1983 to 1990 and the 27 OFFSHORE was made from 1991 to 1998.

Two differences between the boats may be the weight and where the Inboard engines are mounted compared to outboard engines. Also, my 1987 27 FC has an 8-inch fixed keel which may or may not affect it hammering through the rough stuff.

I do not expect fuel economy to exceed 1-MPG at cruise. [I am asuming this data is statute-miles-per-U.S.-gallon. If in some other unit, please clarify--jimh]

JanaSea27OS
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Joined: Mon Dec 31, 2018 5:29 pm

Re: 1992 27 OFFSHORE Twin E-TEC 250-HP Engines

Postby JanaSea27OS » Fri Jan 25, 2019 9:40 pm

I would think the two hulls would be similar. The fixed keel might be better for tracking, although I have never had to fight the helm. My 1992 27 OFFSHORE has Seastar hydraulic steering.

I have owned boats with inboard engines, as well. I find both the outboard-engine boats and inboard-engine boats to be troublesome backing into my slip when there is a breeze or tide.

Cfood
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Joined: Sat Jun 03, 2017 11:44 am

Re: 1992 27 OFFSHORE Twin E-TEC 250-HP Engines

Postby Cfood » Sun Feb 16, 2020 6:53 pm

Thanks for the numbers JanaSea. Big west coast Boston Whaler boats are few and far between, so good data is slim.

I'm in the San Francisco area. and our working weather much the same.

Would a 27 with Whaler Drive be much different?

Jim's performance numbers might suggest a touch better at slower speeds, say cruising 18 to 20-nautical-miles-per-hour.

I do not know if there would be a significant gain in fuel economy with four-stroke-power-cycle engines.

jimh
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Location: Michigan, Lower Peninsula
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Re: 1992 27 OFFSHORE Twin E-TEC 250-HP Engines

Postby jimh » Sun Feb 16, 2020 10:55 pm

Re the influence of a Whaler Drive:

Adding a Whaler Drive to a hull normally configured with a notched transom will add two to three-feet to the hull overall length. The Whaler Drive includes a significant buoyancy box, which remains in the water when the boat is on plane. As a result, the now longer boat with more wetted surface and more weight will tend to require more horsepower to achieve the same top speed as the same hull without Whaler Drive. The addition of the added length from the Whaler Drive improves the ride characteristics. In particular, bow rise in the transition to plane is much less. Upward deflection of the bow in head seas is also reduced, which eliminates the accompanying downward slamming of the hull into waves.

Re the similarity of the hull between a 27 OFFSHORE and 27 FC: I would expect the hulls to be the same, as they have the same length and beam dimensions. However, the inboard 27 FC likely weighs significantly more.

Regarding the weight of a 27 FC and a 27 FC Whaler Drive, I think there may be an error in the catalogue weights. They show the Whaler Drive model weighs less than the notched transom model, which does not make sense to me.

jimh
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Re: 1992 27 OFFSHORE Twin E-TEC 250-HP Engines

Postby jimh » Sun Feb 16, 2020 11:19 pm

Re comparing fuel economy: the two boats are described in completely different units of fuel economy. The usual units for fuel economy used throughout the website are to give the distance in statute miles achieved with consumption of one U.S. gallon of fuel.

Stating fuel economy in the reciprocal units, that is, to specify the volume of fuel consumed in traveling one mile is unusual. If the distance is specified in nautical miles, the expression becomes even more unfamiliar.