2007 Outrage 24 Re-power with Single from Twins

Optimizing the performance of Boston Whaler boats
ibrack
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Joined: Wed Sep 12, 2018 2:56 pm

2007 Outrage 24 Re-power with Single from Twins

Postby ibrack » Wed Sep 12, 2018 3:04 pm

I plan to re-power a 2007 Outrage 24. It currently has twin OptiMax 135-HP engines. I may be hanging a new single Mercury 225 FOURSTROKE engine.

Is [a single 225-HP engine] sufficient replacement power [for twin 135-HP engines]?

Or, will I see a drop in performance?

I would have preferred a 250 or 300-HP engine, but I have an opportunity to get the 225 engine for a good deal.
Last edited by ibrack on Wed Sep 12, 2018 3:47 pm, edited 3 times in total.

jimh
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Re: Effect of reduction in power on performance

Postby jimh » Wed Sep 12, 2018 3:18 pm

The 24 OUTRAGE had 270-HP. If you reduce to 225-HP the performance will change.

If the total weight were the same for both situations, reducing horsepower by a factor of 225/270 or 0.83 would cause top speed to change by 0.83^0.5 = 0.91 or about a 9-percent loss of speed.

Since the single engine will reduce weight, the effect will be even less.

Newportme
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Re: Repower 2007 Outrage 24

Postby Newportme » Thu Sep 13, 2018 7:54 am

I recently re-powered an Outrage 22 Whaler Drive with a single E-TEC G2 225 H.O. My boat will do 44-MPH conservatively; the highest speed seen 47.1 MPH running downwind. Jim H has a 225 G1 on his Revenge 22 W-T Whaler Drive, and in a recent post had a top speed of 43.5 MPH. I would expect similar results on your boat due to the Whaler Drive effectively adding two feet to the hull length.

Bruce

jimh
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Re: 2007 Outrage 24 Re-power with Single from Twins

Postby jimh » Thu Sep 13, 2018 3:22 pm

The originator of this thread started it twice in REPAIRS and Modifications forum, and twice it has been moved to PERFORMANCE.

To get advice about performance use the PERFORMANCE forum. And please read your PM inbox.

ibrack
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Re: 2007 Outrage 24 Re-power with Single from Twins

Postby ibrack » Thu Sep 13, 2018 10:45 pm

Thanks for feedback.

msirof2001
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Location: Southern California

Re: 2007 Outrage 24 Re-power with Single from Twins

Postby msirof2001 » Fri Nov 09, 2018 2:14 am

The 1993-1997 OUTRAGE 24 is probably one of my favorite hulls. I had a 1995 21 OUTRAGE for over 20 years and really wanted the 24 but it was just a little too much out of my range. Honestly, that beast has a 195 gallon fuel tank, cavernous fish holds, storage, bait tank and while the hull's dry weight is 3300lbs, there are a lot of opportunities to add a lot of weight. I personally would put twin Yamaha F200XB 4-cycle engines on that boat. The Orange County Sherriff (Newport Beach, CA) purchased the commercial version (Guardian 24) a couple of years back and they love it. The Guardian 24 has a 125 gallon fuel tank not 195. They stated in an article that it tops out at a little over 50mph. If hanging a single, I think I would consider the new Yamaha 425 HP outboard for that boat. Remember- financial sensibility was left at the coat-check when you decided on boating as a hobby in the first place.
Current: 2017 Everglades 295cc, Previous1: 1995 Boston Whaler Outrage 21, Previous2: 1974 Sevylor Caravelle 3-man liferaft.

Acseatsri
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Re: 2007 Outrage 24 Re-power with Single from Twins

Postby Acseatsri » Fri Nov 09, 2018 8:13 am

Re the comparison to an Outrage 22, I think you're comparing apples to oranges, not the same era or hull design. It may compare more favorably to my 1993 23 Walkaround (4400 lbs hull weight, same hull as a 1993 Outrage 24).

With the original twin 150 hp Oceanrunners, it topped out at around 46-47 mph. With the 250 Honda, it tops out at just about 42 with a 3-blade prop, 40 with the 4-blade but performs much better both ridewise and fuel economy with the 4-blade with close to 3 mpg at nearly any speed below 4500 rpm or about 31 mph, best fuel economy and ride at 23 mph. Anyone who runs this size boat offshore knows that running above that speed is nearly impossible without wearing a mouthpiece in all but FAC waters.

With the lighter hull but a little less power, your boat should have comparable numbers. I find the 250 hp more than adequate for offshore operation, and losing 150 lbs off the transom helped the boat ride flatter with less bow rise. If you don't have trim tabs already, you'll probably want them to compensate for propeller torque causing a lean to one side. My hull seems to be especially susceptible to trim settings when I went from counter-rotating twins to the single, probably more so with the 4-blade. For reference, it's a Powertech OFS4 17 pitch prop, gearcase ratio is 2:1.