12 foot semi V, 8 HP johnson -adding a foil?

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great white

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If you look to my Sig line, you can see the boat and what I have done to it.

12 foot springbok/Prince craft with about an extra 60 pounds of decking, 8 HP johnson outboard.

Its all set up properly and will plane fine. Somewhere aound 15-20 mph, forgot to GPS it last time. My buddy's 14 deep tin with a 35 can catch me, but not by much.

Thing is; the decking has made it comfy and added lots of storage but the added weight has made it slow (well, slower) to plane out of the hole. 2 full size guys it won't plane at all, but it wants to. It runs like a displacement hull and splits the waves with two anglers and gear aboard . It use to plane with two guys before the decking, but took a while to get there.

Once up on plane I can back off full throttle and stay there with a bit less twist, as you would expect.

Compounding the issue is I'll soon be dropping a 2hp on the back and a battery in the nose. 20 lbs for the outboard, at least the same for the battery.

I need the 2 HP since we fish ocean water fairly often. Its not just a flat water tin. Fair seas and only a couple miles out, but rowing to shore is not exactly an attractive "git back" option when wind and tide are against you. I'm always with another boat, but they are usually similarly powered and towing would be a chore at best. You also don't want to be under tow in a 12 foot tin when a 2-3 foot chop sneaks up on you, you need your own propulsion. My 8 HP has never let me down, but there's always a first time....

A bigger outboard seems like the obvious answer and the hull is rated for a 15 hp, but for personal and economic reasons I want to stay with the 8 HP. Translation: no money and it's dad's old outboard.

I'm thinking about trying a foil on the anti ventilation plate. Right now the vent plate just skims the water surface so a foil would be out (or just touching) the water.

What I am mainly after is the quicker to plane claims that they all seem to make.

Planing at lower speeds would be nice, but I can't see how it would do this on a proper setup like mine where the plate is essentially out of the water.

My boat doesn't do a crazy "nose up" out of the hole for more than a couple seconds so its not a big deal there.

Anyone use a foil on their itty bitty tinny?

Help? Hurt? No difference? Type of boat and engine size?

Please no uninformed opinions from what you have read. I would only like to hear from those that have tried them. Whether good or bad.

:)
 
I've got one on my 14' Alumacraft 1436LT and there is zero bow rise - but I'm running a 20hp Mariner outboard too - if your motor isn't powerful enough to plane now at WOT it's probably not going to do much better with a foil. I also have one on my 18' Tracker (150hp Merc Blackmax) which I'd run without the foil prior to installing it (the 14' has always had it) and it did cost me a bit of top speed - which will probably work against you too if your motor is struggling to get to full throttle.

I use the StingRay Jr. and Sr. on my setups.
 
My current boat is a 1648 when i bought the outboard for it a 25hp merc it had a stingray on it. The only thing it did was keep the bow down which isnt always a good thing. I like to keep my bow lifted a bit at slow speed when cutting through larger waves and a foil will not allow you to do this. I took it off and will never use another one.
 
Thinking a bit more with a semi-V a little extra lift might be all you need to get the wedge section of the front up and out of the water so you're not plowing as much...

Waves around here aren't an issue - I avoid Candlewood Lake with the Jon, and that's the only really busy waterway in CT - so having a bit of sheltering bow-lift doesn't do me any favors. I like to get on plane faster so I don't need to run as fast to be on plane as I've got my 2yr old on the boat with me a lot too.
 
[url=https://www.tinboats.net/forum/viewtopic.php?p=357952#p357952 said:
onthewater102 » 01 Jul 2014, 19:36[/url]"]I've got one on my 14' Alumacraft 1436LT and there is zero bow rise - but I'm running a 20hp Mariner outboard too - if your motor isn't powerful enough to plane now at WOT it's probably not going to do much better with a foil. I also have one on my 18' Tracker (150hp Merc Blackmax) which I'd run without the foil prior to installing it (the 14' has always had it) and it did cost me a bit of top speed - which will probably work against you too if your motor is struggling to get to full throttle.

I use the StingRay Jr. and Sr. on my setups.

The boat will plane, its just a little slower to plane than before. Once on plane its fine, I can back off the throttle a fair bit and keep it up.

Was wondering if a foil would give a little quicker to plane is all....
 
I'm running a foil (dolfin? sp?) on my 9.9 hp Merc on a 12ft Lowe Sport V and it works great. The only thing is that it becomes very roll sensitive on plane.
 
I've got one on my 12ft v-bottom with an older 18hp Evinrude. The motor is so heavy for the boat that it will not get up on plane easily without it. Now it jumps right up and hauls butt. It was worth every penny. You need to make sure that your cavitation plate is at just the right height so that when you are at speed the foil is mostly out of the water and then it won't hurt your top end speed. My foil has wings that are tilted up like an airplane dihedral. This seems to be the best kind for my little motor. If you don't like it you can always remove it.
 
That's such a great and often understated point - too many issues with boats planing/not planing nicely etc. aren't a weight distribution or power/weight issue but a motor installation/angle issue. Aligning the cavitation plate properly with the bottom of the boat should get the boat to perform fine - the foil should just allow you to get on plane sooner.
 

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