Motor height on bracket

[workinpr0gress]

Almost a two year anniversery for this thread, lol. Long before me. Maybe I'll pull a measurement and post a pic.

[thehermit]

Thanks Don....removed it to drop and service LU...I can put it aside Prop is a 15x15 OMC Alum.

Bruce...this thread was saved in my favorites

[workinpr0gress]

I run an el-cheapo original Stingray fin on my bracket set-up. It works so well for me that I skipped putting trim tabs on and just run a 15x17 3 blade and might actually go up to a 19. It may not be the norm but it sure runs good on mine.

When I first got the boat wet my only complaint was popping it up on plane and that is a complete non-issue for me now along with having some other advantages. Seems to really help with blowout in hard turns in a sea which I love. Some people don't like that you lose some top end speed which I have seen on other boats. Not with mine, I lost nothing up top. My performance #'s are very good for an old 150 crossflow that sat neglected outside for six years and it surely isn't 150hp, it's not tired it's 22yo, with 40yo technology. I can get 44mph with half fuel and me and the wifey with normal gear, and I'm a few hundred rpm to much at full trim. Really a old OMC 140 V-4 looper would probably run faster and is far from a modern engine. I think the perfect motor for me would be a 25" 90's 60deg. V-6 looper 175 OMC. At only 350 lbs. I could probably lose the foil and the boat run just as good if not better and definitely faster.

I honestly always looked at fins/foils as crutch for various reasons and if it had any weird side affects I would have thrown it in the garbage and got a 4 blade and tabs. The fact that I have had such good results has me changing my thinking on foils/fins on some set-ups. I'll probably be running the foil on this motor til it dies, then we'll see for the next outboard.

[hermco]

That shoots my theory down! Good to know they work on brackets, I have used and installed on many boats without and like the results but never on a bracket boat. BruceB
do you know how high from keel you have the motor mounted?

[workinpr0gress]

That shoots my theory down! Good to know they work on brackets, I have used and installed on many boats without and like the results but never on a bracket boat. BruceB
do you know how high from keel you have the motor mounted?

Nah... I moved it up and down three times...I'll try to get a measurement and a pic today. I do remember thinking it looked to deep/low to me no matter what height I had it at...lol

[workinpr0gress]

I had a nice length of thin wall 1/2" aluminum that I duct taped to the keel and to the motor and checked it a few times. About 3" to the cav. plate and a setbeck of 30"

[strick]

I have a fin on my 20...when I bought the motor it already had one on it so I just left it on...the boat really jumps on plane and turns on a dime without any cavitation. My trim tabs were an unnecessary addition to this boat. Bushwacker has a fin on his Hermco bracket and he has said that he thinks it helps as well. I used to have a fin on a bracketed 23 Arena craft....cant remember exactly why I put it on but I think it was because of blowing out in turns and it fixed the problem. I think the main advantage of a fin is that it will get the bracketed boat up on plane faster. BTW I think fins look ugly..... but if they help

[Bushwacker]

Don,

I raised my motor 2 holes from where you mounted it. Cav plate is now 3.25" above keel. It still handles fine; can put helm hard over at most any speed with no ventilation.


I had a Doelfin on the old 115 and it seemed to help planning when I was heavily loaded on my Bahama trips; I could trim motor down and plane easily at 12-13 mph, allowing me to run comfortably SITTING DOWN in 3-4' head seas. When I added the 30" setback bracket and increased motor weight from 300 to 429 lbs, it wouldn't plane below about 18-20 mph! I added the Doelfin and that reduced min planing speed a couple mph, but it still wasn't as good as what I had before. I then tried a 4 blade prop and that got me back to where I was with the old motor. Denny

[hermco]

Thanks for the info guys. The fins seem to be a big plus. Now can you buy some more boats and let me install brackets for more testing? Just joking. The info you have provided will be quite useful to me and others with bracketed boats.

[thehermit]

After glassing/filling/painting/re drilling. I am @ 3". I paid the price for not drilling right the first time . Need to give it a try next month. One move up would still leave me a little lower than before. Going to seatrial without fin. Then fin can go back on if need be.