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Author Topic:   Outrage 22 Whaler Drive
NewportMe posted 04-08-2011 11:54 AM ET (US)   Profile for NewportMe   Send Email to NewportMe  
Hello. I have a 1989 Boston Whaler OUTRAGE 22 Whaler Drive. The Evinrude 225-HP motor is currently one hole up. The anti-ventilation plate is two-inches above the flat spot on the Whaler Drive. I am running a Stilleto 15-pitch propeller. When the boat is on full-plane wide-open I fetch around 42-MPH. When I trim the motor up the boat will porpoise, The porpoising is easily controlled by trimming down. Would lifting the motor one more hole gain any efficiency?

I sometimes run in the Atlantic outside Casco bay and I am concerned that any gains in efficiency would be offset by blowout in the swells. Any sage advice from the Whaler masters?


jimh posted 04-08-2011 08:51 PM ET (US)     Profile for jimh  Send Email to jimh     
Bruce--I also have a 22-foot Boston Whaler with Whaler Drive, and I have my 225-HP motor mounted one-hole up. Previously I had my motor mounted at the lowest position. My impression of how far up you can go on a single-engine installation on a Whaler Drive depends mainly on the propeller design. More modern propellers seem to tolerate higher mounting heights.

I am afraid that you cannot be certain you have raised the engine as high as possible until you raise it too high. If too high you will see the cooling system water pressure start to fall off and the propeller start to blow out. When that happens you know you went one hole too far, and you can lower the engine one hole.

I have given some though to raising the engine one more hole, to the two-hole-up position, to see if there were any gains or, conversely, any problems. I am rather pleased with how the boat runs now, and I do not have a great curiosity to see if one more hole of added height will be good or bad. Therefore, I invite you to try it and tell us the results!

Phil T posted 04-10-2011 11:06 AM ET (US)     Profile for Phil T  Send Email to Phil T     

You may be aware that raising the motor is a straightforward DIY project. Using the trailer jack for raising and lowering the transom. Given the weight of your motor, I recommend two of your freinds to help steady it.

Tom W Clark posted 04-10-2011 05:15 PM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     
There is a misconception that raising an outboard on a Whaler too high can result in loss of cooling water, but the propeller will loose grip and ventilate long before the motor is really this high.

It is only on very fast high-performance boats which can run their motors at extremely high mounting heights that the cooling water intake becomes a concern.

NewportMe posted 04-15-2011 04:49 PM ET (US)     Profile for NewportMe  Send Email to NewportMe     
Thanks for the replies, Phil good to hear from you. I will raise the motor and report back.


NewportMe posted 04-25-2011 08:03 AM ET (US)     Profile for NewportMe  Send Email to NewportMe     
Update: I installed the batteries over the weekend and trimmed the motor until the A-V plate was parallel with the flat spot on the Whaler Drive. The A-V plate was 1.25-inch above the hull bottom, not the 2-inch that I estimated. I raised the motor to the highest position, and the A-V plate is now 2-inches above the hull bottom. I was not able to do any testing, yet, but will post after I do.


jimh posted 04-25-2011 08:29 AM ET (US)     Profile for jimh  Send Email to jimh     
In my article on propeller testing there is an image that shows the position of my engine relative to the Whaler Drive bottom or flat spot as well as the keel of the hull. See

At the time that image was taken, the engine was mounted in the lowest position. From the dimensions shown, it appears that the anti-ventilation plate of the engine is 0.25-inch above the Whaler Drive flat spot.

NewportMe (Bruce) describes his engine mounting when in the "highest position" (which we will assume means three-holes up) as putting the anti-ventilation plate 2.0-inches above the Whaler Drive flat spot. We assume that the three-hole increase has produced 3 x 0.75-inch or 2.25-inch increase in the height of the engine. Working from my baseline dimensions, this would mean the anti-ventilation plate ought to be 2.5-inches above the flat spot of the Whaler Drive. We have about 0.5-inch of difference, which we will have to assume can be attributed to variations between engine manufacturers in the actual length of the outboard. And, of course, I am assuming that both the engines are designated at 25-inch shaft engines.

When I fitted a new engine on my Boston Whaler, the dealer was quite strong in his suggestion that we try mounting the engine one-hole up. Again, working from my dimension in the reference article and assuming that the two engines have the same length, this implies that my current engine is mounted with the anti-ventilation plate 0.75-inch higher than shown in my illustration, or about 1-inch above the Whaler Drive flat spot. The engine has two more holes of lift available, and if moved to the highest position its anti-ventilation plate would then be about 2.5-inches above the flat spot of the Whaler Drive.

I will stand by for Bruce to report on the boat handling and feel with the engine in the newly raised position.

NewportMe posted 04-25-2011 03:21 PM ET (US)     Profile for NewportMe  Send Email to NewportMe     

I will make an effort to clarify my statements. There are 4 holes in the upper mounts to my motor. My motor is now mounted in the lowest hole (all the way up). Before Saturday the motor was mounted in the second to the bottom hole (2 holes up?). The a/v plate is now 2.125" higher than the "flat spot" on the whaler drive. I was rounding my measurements, and did not take any measurements from the keel.
Hopefully I will be able to check the performance and the handling this weekend...we will see what the weather brings.


jimh posted 04-25-2011 08:39 PM ET (US)     Profile for jimh  Send Email to jimh     
Bruce--Our measurement systems are now within 0.25-inch of each other, which is certainly close enough to attribute variation to any one of several sources:

--location of holes drilled in transom

--measurement error in extending plane of the Whaler Drive flat spot to the plane of the anti-ventilation plate

--variation in the shaft length of our engines, even though both are specified as "25-inch" shaft length.

NewportMe posted 05-01-2011 09:56 AM ET (US)     Profile for NewportMe  Send Email to NewportMe     
I made it out for testing/fishing yesterday. My new average top speed is 44 mph (1 run with wind 1 against). There are no negative effects that I noticed yet. No ventilation or blowout of the prop during hard turns, there was no swell as I was on a lake. The cooling stream was strong, as Tom had mentioned, This change did not eliminate the porpoising but did lesson it to an extent.
I don't know if the higher top speed will result in any measurable efficiency gains but I'll take what I can get. The boat seems lighter or higher in the water at speed and suffers from no adverse handling that I have discovered thus far. Overall the change seems positive, but time will tell.


NewportMe posted 05-01-2011 10:03 AM ET (US)     Profile for NewportMe  Send Email to NewportMe     
Oh my son and I did manage 2 fat 19-inch landlocked salmon in a few hours of trolling. A great day to be on the water.


jimh posted 05-01-2011 01:07 PM ET (US)     Profile for jimh  Send Email to jimh     
Thanks for the quick summary of results.

There is no misconception about the effect of raising the engine on the cooling system: the higher you raise the engine the more cooling problems may occur. Modern outboard engine gear case design has evolved, however, and on my current engine, for example, there is a water inlet for cooling that is located on the leading edge of the nosecone of the gear case. This inlet is going to be in the water all the time, unless you have your engine running in mid-air.

My engine manufacturer (Evinrude) also provides several different types of inlet covers for the main water inlet, with several types intended to increase cooling water pressure and flow in compensation for raising the engine mounting height. I think there are even some designs which begin to look like scoops, again intended to improve cooling water flow when the engine mounting height is increased or there are other problems with cooling water flow. Some boat hull bottoms have some strakes or other appendages which can affect the flow of cooling water into your engine.

The Whaler Drive does seem like it affects the flow water into the engine, as the water coming off the hull tends to become aerated. If you look at the water behind a boat with a Whaler Drive and compare it to a similar hull without the Whaler Drive, you will see--well I guess I should say "I see"--the water coming off the hull looks to be very aerated--bubbly. From this I surmise that the water coming into the engine gear case on a Whaler Drive may contain more air than on Boston Whaler hulls with a standard or notched transom engine mounting. Airy water probably does not work as well for cooling as solid water, but so far I have not seen any problems at my engine mounting height.

Tom W Clark posted 05-01-2011 01:39 PM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     
Bruce -- Are you using a "Stiletto 15-pitch" Advantage or Bay Pro?
NewportMe posted 05-01-2011 06:21 PM ET (US)     Profile for NewportMe  Send Email to NewportMe     

I believe it is an Advantage but I will check tonight and post back tomorrow.

jimh posted 05-01-2011 06:28 PM ET (US)     Profile for jimh  Send Email to jimh     
Also, congratulation on the 44-MPH. This is faster than I can go on my REVENGE 22 Whaler Drive with 225-HP. The best I have seen is about 42.5-MPH. Like your results, that was obtained on the edge of the boating season, with cold water, cold air, and in my case a bit of a tail wind and a light load.

I think 44-MPH is a respectable speed for an OUTRAGE 22 Whaler Drive, but you might be able to tweak a few more tenths-of-a-MPH out of it with some further testing. Good luck.

NewportMe posted 05-02-2011 07:21 AM ET (US)     Profile for NewportMe  Send Email to NewportMe     

The prop is an advantage II 15 pitch. At WOT during my highest speed run downwind I was running around 5850 rpm. Motor is E225CXCCE, I believe this indicates that the motor is counter rotating but prior to my ownership the lower unit must have been swapped because the rotation is right hand.


NewportMe posted 05-02-2011 03:56 PM ET (US)     Profile for NewportMe  Send Email to NewportMe     

Thanks for the encouraging words, this site has been an invaluable resource to me and many others. Hopefully I can leave a small scrap of information that will be a help to someone, or help them try to improve their boat somehow. The amount, and quality of information here is awesome.


Tom W Clark posted 05-02-2011 07:28 PM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     
Bruce -- Yours is a very interesting data pint. i would not have thought the Stiletto Advantage would be a good fit on a Reveneg 22 Whaler Drive, but what do I know?

So, do I understand correctly that your motor is now "two holes up" on your Whaler drive?

What about raising it another hole?

Jim -- Given Bruce's report, do you have interest in trying a 15" Stiletto Advantage on your boat this summer?

NewportMe posted 05-03-2011 07:43 AM ET (US)     Profile for NewportMe  Send Email to NewportMe     

My boat is an Outrage so it should be lighter than a Revenge, I don't know if that would change your opinion on the prop. My motor is currently all the way up (3 holes?)


Tom W Clark posted 05-03-2011 10:46 AM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     
Bruce -- The Outrage 22 Whaler Drive is specified at 2500 pounds. The Revenge 22 Walk-Through Whaler Drive is specified at 2600 pounds, only 100 pounds more.

I suspect the frontal area of the Revenge 22 Walk-Through will have a greater effect on top speed that the trivial added weight, but even that should not be that profound.

So your Evinrude is three holes up and Jim's is only one hole up. Do I have that right? That suggests Jim has lots of room for moving his motor up and the potential to gain both speed and fuel economy in doing so.

NewportMe posted 05-03-2011 04:04 PM ET (US)     Profile for NewportMe  Send Email to NewportMe     

Wow only 100 lbs. I would think the tables benches cushions etc. would tally over 100 lbs. but who knows. I am quite pleased thus far with the prop but what would be your suggestion for one. I may damage mine.... or hit the lotto, any information I can salt away is appreciated.


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