Hyrofoil/Fin Test

[GoneFission]

OK, I curiosity finally got the best of me, so I decided to try a foil/fin on my 22-2CCP and motor.  I decided to go with the SE Sport 300 because it had been favorably reviewed and was supposed to be the fastest of the foils according to reviews, and was reasonably priced for $49 at Overtons.  

Installation was easy and uneventful, with four 1/4" holes drilled in the cavitation plate of my 200HP Mercury V-6.  The SE 300 comes with a handy drilling template that makes it hard to get it wrong.  Then off to the water to see what it would do!  

After leaving the no-wake some of the marina, I dropped the throttle and the boat went easily to a plane.  However, I could not tell a big difference with or without the foil, as my 22-2CCP has always planed well - note that I have a Quicksilver Power II propeller that starts at 13 pitch and then shifts to 19 pitch at 5000 RPM.  The boat was more sensitive to trim with the foil.  I tested at different speeds and RPMs (all RPMs are at 19 pitch with trim to best speed) to compare the before and after results.  Here what I got:  

RPM---Gal/Hr--MPH---MPG--G/H w/Fin-- MPH w/fin--MPG w/fin
3000----8.3-------24----2.9------8.4----------17------------1.7
3500----8.5-------26----3.1------9.2----------23------------2.5
4000----9.5-------28----2.9------10-----------26------------2.5
4500----11--------30----2.7------12-----------31------------2.6
5000----15--------37----2.5------16-----------37------------2.3
5500*---18--------40----2.2------20-----------39------------2.0

*note the boat would only make 5300 RPM with the fin, not 5500.  

As you can see, my 22-2CCP was slower and consumed more fuel across the spectrum with the foil/fin installed.  It would maintain a plane better - at 3000 RPM my boat is on and off a plane with no fin - with the fin, it was solid on a plane, but nose-high, plowing, and slow (as the numbers surprisingly show).  I was able to hold a plane at 2700 RPM with the fin, but it was kind of silly - like a big plow in the water.  

Foils are supposed to cure boats that tend to porpoise, but the addition of the foil on my boat actually caused it to porpoise at high speeds!  I think the fin was just barely in the water at high speed with a little "out" trim on the motor.  My motor is mounted with the bottom of the cavitation plate just above the bottom of the V in the hull, so I think the porpoise came from the fin entering the water stream, lifting up, and then going out of the water stream.  When lift was lost, it would go back down into the water and repeat the sequence.  

To summarize, my 22-2CCP was slower and used more fuel throughout the range.  I took the foil off the boat - even easier than installing it!  However, as the EPA says, "your mileage may vary."    I think the SE Sport 300 foil could be a useful product for a boat was difficult to get on plane (read high pitch prop and lower power), AND had the motor/outdrive mounted low enough so the foil is always in the water.  It fits all outboards from 35 to 300 HP, as well as sterndrives.  A tail-heavy boat with a high-pitch speed prop or sterndrive might be the ideal use.

If anyone wants to try it out on their boat, I have a very slightly used (just in the water one time!) black SE Sport 300 in original packaging, with all hardware, that I will let you have for $39 delivered to your door in the good 'ol US of A - that's $10 less than Overtons...

Now let's go fishin'!

[JimCt]

Thanks for the report!  I think foils are perhaps mostly of benefit to boats that have a stern-heavy trim or are loaded a little heavy.  Different foil makes may also yield better or worse results.  I got an aluminum Bob's Machine foil from John (Jones) but haven't installed it yet on the 170.  Will put it on this summer sometime and report what happens.

[RickK]

Good stuff, thanks.  I experienced a loss of MPH with a Bob's plate of about 1.5 - 2 (don't have the flow meter) and didn't notice too much difference in planing quickness.  I too, took it off. The best thing I found was to put my big fishing buddy in the front of the console on "take-off" and all is good. With both of us on the back, it's harder to get on plane.
That prop sounds interesting - have to check it out.  How'd you get the prop to go to 19 degrees at low rpm?  I thought it switched at 5k. Can you change it on the fly?

[GoneFission]

The prop shifts at a pre-set torque loading, which is adjustable.  I have mine set at about 5000 RPM, but it's kind of like an automatic transmission, in that it will shift lower if there is less torque on the prop.  

Once it shifts, it stays at the higher pitch until the blades are unloaded, such as returning to idle.  You can also force the shift back down at lower speeds by lifting the throttle (to unload the blades) and then getting back on it at the lower pitch.  Again, kind of like the throttle kick-down on an automatic transmission.  

The first and best-known shifter prop is the Land 'n' Sea.  However, a fire with a major supplier has them out of the prop business.  You can find info (and an amazing video!)    on the Land 'n' Sea torque shift prop at:  
http://www.land-and-sea.com/marine/torq ... -shift.htm

The Land 'n' Sea torque shift propeller is a neat product, and I hope that whomever winds up with the tooling and license (Bombardier?  Brunswick/Mercury?) has the financial and marketing capability to promote it!

My propeller is a Quicksilver Power 2.  It is not as adjustable as the Land 'n' Sea and is available in set pitches of 13/19, 15/21, 17/23, 19/25, and 21/27.  The 19 is about perfect for my boat.  I don't think the Power 2 is still sold by Mercury, but replacement parts are available, so you could build one if you wanted.  The Land 'n' Sea is very flexible, with adjustments for both top pitch and bottom pitch, as well as shift point.    

Both Land 'n' Seas and Quicksilver Power 2s show up on eBay from time to time, and usually are a LOT less than the $1000 list price...   :)

[RickK]

$1000  
Hmmmm
Honey I found this really important thing that the boat MUST have other wise it will sink!!!
Think that will work?

I couldn't find a trace on eBay - it's sometimes hard to do a search and get what you want without 5,000,000 other results.  :cry:

[ddd222]

when it comes down to it, the foil/fin was for the most part a quick fix that wasn't/isn't guaranteed to work the same on every boat. The only sure fire fix for this boat, as i have the same hull would be tabs. After installing myself and using the boat i really don't ever want to be w/ out them. I can't quote the benefits that bennett and lenco claim about fuel savings, and faster to plane, my boat has a 250hp efi, so planing happens in about 2 seconds and trying to improve on that would be a waste of time. But changing the boats attitude at the quick flick in numerous situations, passengers moving around, different amounts of fuel, gear etc., they really make a night a day difference. Haing installed bennetts and used them for 2 seasons, i really can't say enough about the product or the customer service. But if I had to do it all over, i would definately go w/ lenco's. My tabs have a trickle leak from the hydralic line somewhere that i can't find and no amount of customer service will help, question of me getting to the lines that were snaked around the god awful glaased in livewell on my 87' 222. Assuming the tabs worked fine and didn't leak, 2 others drawbaks of the bennetts are where to mount the hpu w/ limited space, and the cost of replacement which is over $300. From what i can see if you decide to fix the problem the boats having, and u decide to go w/ tabs, the lenco's may initially cost $50-80 more than the bennetts, but will likely take the same time to install, take up less space, and have less parts to replace. I would like to say otherwise because the bennett people were so nice to deal w/ and very helpful and professional, but electric tabs seem to make more sense to me. Hope u decide to install them, u will definately be glad u did

[Radioshop]

Hmm, the foil worked well on my 13' Whaler when I was a kid.  Sounds to me like the foil myth is busted though, unless there's a porpoising problem.

[ddd222]

i forgot to mention which may be helpful is re-distributing some of the weight of the boat, unlikely it will change things that much but may help, and have probrably been mentioned before. I didn't see what year yours was but if you have the coffin box may want to add weight, moving batteries off splash well to the console, also had a friend move his console forward, but that needs a little more attention and modifications. And last but not least maybe the foam in your boat may be saturated and wet changing the boats ride, but with all the guys here w/ older 222's, i think every one has a bit of wetness, likely addressed only with soft decks and transoms. And BTW the boat seems powered right and prop changes can't solve everything.
      Thought i would mention these few things after suggesting trim tabs, which also suggests time, money, and cutting holes in transom, which is the hardest part! Money aside, install manuals for both mentioned quote 1-2 hours install. I saw them do it in a shipyard on ship-shape tv in about 2 hours, 3 guys, perfect/ample tools resources at their disposal, not to mention the boat being 2/3 together after total refurb with everything in the transom area exposed and easily accessed. All said and done i think i had between 9-11 hours on the install by myself, not including the 3 hours i sat staring at the transom and the 3/4 inch hole saw, and the transom, the saw, the measurements, the saw, the transom, ..................BTW, placement of tabs on my boat came real close to the outside stringers, one reason it took me so long to finally get the stones to make the cuts, best luck whichever route u choose

[John Jones]

All I can say is the Bob's Machine Stabilizer that I sold JimCT really helped my '02 Key West 1900.  Hole shot, lower planing speed, better bite while turning.  I could trim up farther without blowing out which gave me about 3mph higher top speed.  Oh well, every boat is different.

[Tailgunner]

Well, that settles it. I placed one of these on my '73 222 and thought it was the greatest thing since sliced bread due to jumping up on a plane so quickly. I did notice my top end dropped slightly but had failed to check on fuel consumption prior to mounting it. Thanks for doing that GoneFission.

I'm going to take mine off after I burn a full tank and measure the usage. Then I'll measure again and see.

[GoneFission]

I think the foil will work on some boats; it just did not work on mine.  Again, my 22-2CCP is not a tail-heavy boat, and getting on a plane is not a problem for me.  Also, I think the deep-V CCP is different than the semi-V hulls in the 170s and 190s and 222s.  

I had great success with a foil on a bass boat I used to have that had two rear livewells and a big motor on the transom.  It was a pig out of the hole, but would scream at high speed.  I gave up a bit of top end (who needs to run 70+ anyway?) and the foil really made a difference in the hole-shot.  I figured for $50, why not see what it does to my AS?  I was surprised at the fuel consumption difference - did not see that coming...

[steved]

Thought I would put in my 2 cents.  I put a Permatrim hydrofoil on my 1982 Mariner 200, which is on my 1982 222 CCP at the middle of the season last year.  My boat stays in the water all season so we just pulled it up on a sling, drilled the holes, bolted on the Permatrim and dropped it back in.  I had the feeling that I was getting up on plane faster and staying up until I dropped to lower revs than before putting on the foil but I didn't do any real testing.  In addition, I found that I was getting quite a bit of spray off the bottom of the transom.

At the start of this season, we moved the motor up one notch on the transom. What a difference! I am definitely getting up on plane faster and staying up longer (sounds like I should paint the foil blue!!) and the spray is gone.  The wake is just beautiful.  

Don't have any empirical evidence about gas consumption, but it seems to be better.

I should note that I NEVER (well almost never) run the boat wide open, as I really have no need in that I am very close to my fishing spots.  Also, I try to treat the old lady with respect.  So I don't know about impact on top end - although the logic is that it would lose something.

So, as far as I'm concerned, the foil has been a positive.

[scott_gunn]

I have a StingRay hydrofoil and am glad I do.  My boat would porpoise.  I would take it off if I had tabs, because I definitely lost a little bit of top end, and I assume the same drag responsible for losing top end is hurting my fuel economy.  But I still like it overall.

[John Jones]

So I don't know about impact on top end - although the logic is that it would lose something.

Yes, first thought would say it adds drag so it must be slower.  However, as you found, raising the motor can make a big difference.  Just because that's where a motor has been for 20+ years doesn't mean that it is the most efficient place.  If the foil causes lift on the back end, then there is less boat in the water and probably less drag than caused by the foil for a positive gain.  In my case, I could trim out farther without cavitating, which gave more lift and a better thrust angle, therefore less drag.  I know people that never, ever use the trim except to raise the motor out of the water.  The most efficient angle for the motor is for the prop thrust to be on the same plane as the surface of the water.  This angle is different at every change in rpm.  Even if one is not a speed demon, changing the trim angle can make the boat more efficient at most any planing speed.  Play with the trim once you are on plane.  One might be surprised.

None of the babble below directly concerns foils but it does demonstrate what getting the ass end out of the water can do for you.
Ballpark examples on my 22-2.  Ballpark because my Navman F2100 fuel flow meter stays broken more than working but that is another thread.
Once on plane, I try to run 4200 or so rpm at cruise which seems to be the most economical for my gas hog motor while remaining on plane.  This gives me about 19-21 mph depending on chop, wind, and load.  (By the way, most don't realize that a boat has less drag on a chop than on glass slick water.)  I immediately raise the trim to the first mark on my gauge.  Speed jumps up to 23-27 mph and rpm increases to 4600 or so without touching the throttle.  I back the throttle off to 4200 or so again and lose a little speed.  Then I play with the trim in tiny increments while watching the speed on the gps until I find the spot where it runs the fastest while tweaking the throttle to keep the motor at the same 4200 rpm.  That is the most efficient spot for that days conditions.  Then, I start hitting "bow down" on my Bennett trim tabs in maybe 1/2 second adjustments.  This brings the stern up slightly and the speed and rpm go up again.  By tweaking the throttle, trim, and trim tabs I can drop my fuel consumption from initial 21 gph when first getting on plane to 11-13 gph at 25mph which at $3/gal is a helluva difference in my wallet on a run of any distance.  No, I don't do all this tweaking just puttering around but down here the coastal waters are so shallow we have to make long runs offshore to catch bottom species.  At current water temps the bottom fish are holding at 80-100 feet which is 20 miles or more offshore.  It's 11 miles to the inlet from my house, plus running to different spots.  It's nothing to put 80-100 miles round trip on the boat on a serious fishing trip.  That much gas and oil makes all the tweaking worth the effort.  Bottom line with all the rambling is that anything to reduce drag is better.  If a foil adds a little lift or allows for trimming up farther it will make the rig more efficient.  If one doesn't play with all the tools available then it will just be that much more drag.

[Ben87]

This is this is the kind of thread I've been wishing for, something that is directly applicable to MY boat.  John Jones, in your last post, I learned something new in that I didn't think that the boat was more efficient in a chop than on glass smooth water but now I can understand why it would be better with some ripple or chop, but not enough to affect ride quality.  

I play with trim all the time and know it has a huge effect on ride as well as efficiency.  I have no trim tabs but I twiddle with the trim all the time as the water is so variable in the sound I run that there is every kind of condition available in a 10 square mile area that it is done out of necessity.  

I don't think my 222 would benefit from tabs since when I have the motor trimmed all the way in, the bow stays pretty flat on the water as I believe the new engine trims in lower or closer to the transom than the old Mercury did, which is good, I've also noted that I have a much better bite in corners, perhaps the lower unit or the entire motor is longer???

Anyhow, I'm glad this thread came about, I just wish there were many more like it on the way, on the other hand, it could very well be that almost everything has been covered since the site's inception.