Add lifting strakes to 24' Harris Floteboat?

[countrybrianf]

Just bought My pontoon a few days ago. Wanting to add strakes to get more speed out of it but want to know if it will help with my motor. Already done a lot of research but haven' found anyone with the same style setup with strakes. I have a friend that is a fabricator and can build the strakes for me and weld them on for cheap.

My boat is a 1996 Harris Flote Bote with 3.0 LX Mercruiser, Alpha One , 2 toons, Nada.com says the it weighs 2290lbs.
Right now i can go 25-26MPH @ 4,500 RPMs an 20MPH @ 3200 RPMs.

 

[countrybrianf]

Re: Add lifting strakes to 24' Harris Floteboat?

Also my prop I think it is a 18" diameter and i know it is a 13 pitch. Bought the boat for $3,000 with every thing you see in the pictures.

 

[MaPaHa]

Re: Add lifting strakes to 24' Harris Floteboat?

I had lifting strakes added to mine but the boat is not the same build. It?s a 22 foot boat and I first added a center toon with lifting strakes already on it, then added strakes to the older outer toons. I had an older 140 hp (about 115-120 in today?s standards rated at the prop) and I liked the way the boat performed. I now have a mid 90?s 150 Johnson on it and I never dreamed a pontoon could run this good. My son and I had it on the river today and clocked it at 38 mph GPS down river and 34 mph up river for an average of 36 mph. It jumps out on plane and pulls very strong. We had 9 people in it last week and it cruises good at 4,000 rpm on plane.

Here?s the nightmare? The welder that put them on (not with the welding shop any longer) burned through the pontoons in several places and there are several pin holes in them. The problem is the holes are not where you can fix them by just going over the welds. The leaks are in the pontoons behind the strakes and are not accessible. It sounds like a good friend and a good deal but just make sure he has plenty of stick time welding pontoons. If you wind up with holes burned in the pontoons behind the strakes? you?re screwed! Sorry for the putting like this but I?ve spent too many hours trying to figure out what I?m going to do, and the welder has spent a good bit of time on it trying to make it right but there are still leaks in my pontoons.

At the rate mine are leaking it?s obviously not dangerous or I wouldn?t have it on the water, but the idea of the pontoons taking on water bugs me to no end. I?ve come up with an easy way to get the water out while I?m on the water and my three pontoons together calculates out to about 12,500 pounds of buoyancy so a gallon or two of water in the pontoons is not a safety issue but I want them dry.

Overall, I think adding strakes is a great idea and I think you will like the results, but whoever welds them on needs to be an ace at pontoon welding. BTW, you will likely have to re-prop after you?re done. A nice 4-blade (stern lifting) pontoon prop could help. I just installed a prop from Power Tech that?s an off-shore 4-blade SS. They will help with the selection but you have to buy it through a dealer.

 

[5150abf]

Re: Add lifting strakes to 24' Harris Floteboat?

You have to be real careful with this, aquadynamics are a funny thing, a foot too long or too short and it won't handle right but if you have a friend that does aluminum fab you can probably fine tune it.

I am with Bennington in the weld shop and very rarely does R&D get chines on a new boat right, I almost always have to add or cut off to get them to run right and they do this for a living and have actual parts to use, designing your own chines could be a challenge, I would try to talk you into buying chines from an established toon company and having them welded on it will take away one piece of the puzzle.

Might cost more but like I said, it will take away a piece of the puzzle then you just have to figure out length, which normally are full length on the outside and about 2/3 of the tube the inside

 

[MaPaHa]

Re: Add lifting strakes to 24' Harris Floteboat?

5150abf,

Am I right in thinking that: if the strakes are too long the boat may run too flat without enough bow lift, and if they are too short the stern may run too deep and bow up? Are there any other issues with shortening or lengthening them that would affect turning?

After having them added to my 22 foot boat with a 150 Johnson, it seems to run about right. The bow rides up and the water line on plane is about ? way down the outer strake. Even when you have people in the front the boat has lift to pick up the front. The only complaint I have is that the boat is a little hard to turn at full speed (mid 30’s), but turns good around mid 20’s where you would typically pull a tuber.

My center U tube is 25 inches deep and built on a 23 inch diameter round. My outer tubes are 23 inches round so the center tube sits 2 inches deeper. All three tubes have lifting strakes on them all the way down on both sides. The strakes are one piece with a slight curve on the bottom and set about level on the bottom and straight vertical up the sides. The center tube is aft about 18 inches with a 5 1/2 inch jack plate. The motor is a 25 inch X-long shaft with the cavitation plate about 1 ? inches deep in the water. Prop is Power Tech off-shore big dia / big ear 15 pitch 4 blade.

My question is: did I get lucky or could adjusting the length help the turning? I obviously can’t add any more length and I’m happy with the bow lift, but if I cut any off it seems that the stern would run deeper which I don’t think I need but might do it if it would help the turning. Are there any other tricks that would help with turning?

Thanks

 

[Mi duckdown]

Re: Add lifting strakes to 24' Harris Floteboat?

Country. Enjoy your boat. don't over think things.

 

[The Woo Woo Kid]

Re: Add lifting strakes to 24' Harris Floteboat?

+1.

But if you must, and based on what the other guys said, perhaps your best bet would to find a boat like yours that already has strakes and copy, measure, etc. Not easy to find but maybe you'll get lucky.

There's always the waveglide option..... a mini third pontoon.

What diameter are your toons ?

For comparasion's sake....

Suntracker says strakes add up 41% more speed and 34% better gas mileage.

http://www.youtube.com/watch?v=0D0JwePW21I

Mine has strakes. It's a 2008 22ft Suntracker Regency w/ 26 in toons. The playpen measures 22 ft. the deck 24 ft+ so it compares to some 24fters.

Haven't been able to measure the speed, no speedo yet, but on my maiden voyage last weekend it was pretty fast. And smooth. Another thing the strakes help with.....Absolutely no splashing to the boat's interior or passengers. None.

Boating world did a test of a boat/motor exactly like mine and they got 41 mph, slight chop and even more wind.

http://www.youtube.com/watch?v=pZz34u99Srk

 

[5150abf]

Re: Add lifting strakes to 24' Harris Floteboat?

MaPaHa,That is the fun of it, you don't know until you try it, it could get better or it could get worse, you won't know until you try it but generally on our boat the inside one is shorter but we do have one that they are the same length.

On our ESP boat which is our banking model we have only foils on the inside of the tube and unlike a chine that si wide and flat these are pointy and angle down into the water so they give lift but allow it to turn really sharp ut again it was all trial and error.

I think if you got your to run that good and you only have one minor complaint I would let it go because you probably got pretty close to what your boat needs.

 

[Bamaman1]

Re: Add lifting strakes to 24' Harris Floteboat?

Lifting strakes don't work on all boats. For example, you wouldn't put them on a boat with a 50 hp, as there's not enough power to get the boat planed out and to hold the nosecones in the air.

I cannot recall any strakes on I/O's with the 140 hp motor. Your motor is realistically about equal to an 85 hp 2 stroke outboard, and is more of an economical slow cruising motor than a kick ***** 40+ mph motor.

You'd do best to accept your boat and its limitations, and to spend the money to replace the seating. Your present speeds are perfectly okay for day to day cruising.