Trim Tab Upgrade

[Outta Here]

I have Bennett 12-24's on a 23 Parker. Love 'em. Large tabs = free extra planeing surface. I get instant response with just a touch.

I can bury the nose any time. Parker might use "too small" tabs to keep boating novices safe. Look how many threads on other forums "OK for tabs down in following sea?" or, "What are tabs for?". Easy to get in big trouble with big tabs.

 

[Megabyte]

Parker might use "too small" tabs to keep boating novices safe. Look how many threads on other forums "OK for tabs down in following sea?" or, "What are tabs for?". Easy to get in big trouble with big tabs.

True... Very true.
Never thought about it that way, but you could very well be correct.

Can you imagine someone with a set of 24x12's fully deployed, and running an inlet in a following sea? :shock:

 

[DaleH]

Parker might use "too small" tabs to keep boating novices safe.

Unfortunately, I believe they use 12x12s on all their boats so they can buy them in quantity. I don't buy the "safe boating" notion one bit, but my opine only. It's really my only complaint with Parker boats.

 

[susqking]

I have been using the 12 x 24 since spring and this has to be the best upgrade you can make. It's like I have a different boat.

 

[Par]

OK, guys after some study, I am now convinced that replacing my B12x12E tabs with B12x18E tabs is the way to go and that not moving the actuator and drilling new attach holes 3 inches offset on the blades is an acceptable installation method. But of course I have some questions. :roll:

Par, where did you get your replacement blades? What came with them, just screws? Was there installation instructions? Short of calling Lenco, I can't seem to find them anywhere. The website talks all about upgrade blades, but does not talk about installation requirements (like having to move the actuators).

After drilling the new mounting holes on the blade, what would you guys do to fill in the old holes, if anything? Properly done would require welding (which I don't know how to do) with a heli-arc (which I don't have).

Last question, for now. My bottom is painted because the previous owner kept her slipped. I don't keep her slipped. My current tabs are painted. I wasn't intending to paint the new ones. Pros, cons, thoughts?

John

John - I purchased the blades from www.southernangler.com. They were $126.00 a piece. This was for the blades only. No hardware was included so I just bought the extra 8 screws from West Marine.

There are no upgrade instructions included so I used the install manual on Lenco’s site. There was more than enough info to get the job done. I also used marine-tex to fill the old screw holes and put a nice layer of 5200 just to be safe.

I finally ran the boat this passed Friday for the first time since I installed them. Even though, like expected, the far outside edges of the blades are out of the water when on plain, they still made one heck of a difference. I was able to get on plain much, much faster then before. The ride was absolutely better as well. There was some wind chop and swell and it was all but un-noticeable. The ride was 100% better then with the 12x12’s.

Brian

 

[rangerdog]

Just what I wanted to hear, thanks Par, 100% is something to look forward to!

 

[John_Madison CT]

I think you've convinced me to do the same after I haul this December.

The link to your vendor does not work correctly, can you please check it?

 

[Porkchunker]

I was toying with the idea of larger tabs a couple of years ago, but because of the cost, opted to go with a pair of those flat SS plates mounted to the bottom of the anti-ventilation plate of each F-115. They are made by Cobra Marine, and only cost $69 each. Those two plates add enough surface area to lift the transom, (overcoming the weight of twin 4-strokes) and make the 12"x12" Lencos MUCH more sensitive.

If I had known that I could install wider Lenco plates and offset them by up to 3" I probably would have taken that route, rather than drill holes in my lower units. But now that they are there, and the plates work great, I won't be swapping tabs out.

If and when I repower (probably to twin F-150s), larger tabs will be back on the table.

 

[Par]

I think you've convinced me to do the same after I haul this December.

The link to your vendor does not work correctly, can you please check it?

Woops. There was a period at the end that was not supposed to be there. Here ya go: http://www.southernangler.com/

 

[Chop~Chop]

I may be over-thinking it, but I'm considering another option to get reasonable performance this year before I'm in.

I could redrill 12x12 tabs so the actuator mounts about 2-3 inches from the end of the tab. Obviously then, tab will be partially deployed all the time. If I want to bring the bow up, say on a flat calm day, I could use trim of outboard.

Last season I usually had tabs fully deployed all the time. So I'm thinking, repositioning actuators on tabs so they end out close to the fully deployed position Parker had setup.

I don't know if there is a potential problem with this as I can't picture how much the hinges on an actuator are required to move when I deploy them... :?:

It seems as though those hinges don't really move at all.

I think the only draw back will be mpg but I can't imagine how much :?:

Advice will be greatly appreciated.

 

[Megabyte]

I think the only draw back will be mpg but I can't imagine how much :?:

More than the fuel burn question, I'd be more concerned with performance in a following sea.
If your tabs are always partially deployed due to an altered mounting position of the actuator, you will not be able to fully retract them, thereby possibly causing handling issues in a following sea.

The smaller size of the trim planes may minimize any adverse effects, but it is something you might want to consider.

On the other hand, the larger the tabs, the larger the good and bad effects...
Those of us who have installed larger tabs can more easilly get on plane or stuff the bow when we need to, but we also need to be more aware when to retract them when sea conditions dictate.

It's just something we all need to be aware of when operating in changing conditions. :wink:

 

[Porkchunker]

...Last season I usually had tabs fully deployed all the time. So I'm thinking, repositioning actuators on tabs so they end out close to the fully deployed position Parker had setup...

What kind of boat (MV or DV) and what motor (single or twin, 2-stroke or 4-stroke)?

If you are running tabs down all the time, you are either too heavy in the transom (e.g., twin 4-strokes like me), or are trying to run the chop too fast (over-driving the hull for the conditions) and feel you need to soften the ride.

I had a similar problem, in that I couldn't get the bow down sufficiently to give a good ride even with the motors trimmed all the way in. I believe that the twin F-115s brought the center of gravity to the rear sufficiently that the tabs were ineffective. So...I was running around with the motors trimmed all the way in and the tabs partially deployed most of the time.

I was going to go to larger tabs, but didn't want to drop neary $600 for the upgrade. Decided to try the SS plates (as described above), which solved my problem. With the addition of the plates, I run the motors at neutral trim and the tabs fully retracted. When I need tabs, they are now very effective. Pics of the plates are elsewhere here in the projects forum.

 

[DaleH]

Last season I usually had tabs fully deployed all the time.

Fully deployed ALL the time :?: ?

Wow, that'll kill your MPG by 40% or greater. Chop, I have tested my mod-V with the WIDE Bennett trim tabs against another Parker mod-V with 12x12 Lenco tabs, that used to be on the Parker River, both boats running running V6 225hp OBs and using Navman or Flo-Scan fuel computers, and I can easily dial in a 10% improvement versus the use of "no tabs". In identical sea states and attempting to bring down the bows to the same point (best we could riding side-by-side) ... I was getting at least 30% better fuel economy with the wider tabs.

Look ... I'm still workingo n my boat in the Pert Lowell boatyard behind Fernalss Marine. Stop by and see me some time or catch me when on the mooring (Memorial Day weekend), I'd like to catch up with you and can help you out with your tab situation, even a new install, if that is the route you go.

There's no way you should have to live with your tabs deployed FULL all the time ... that's craszy ...

 

[Chop~Chop]

Deployed full "all the time", no, often though...I guess I've over embelished; my boss accuses me of going 6-sigma on him, too often. He thinks I'm crazy too.

The boat with F225 at end of monster bracket is definitely too heavy in the transom. I've always had to run with OB trim all the way in, just like Porkchunker did before his retro. I'm thinking now, plane mounted on the OB like Porkchunker can get me closer to right this year. I've seen different ones though. I think they are not metal and attach by wrapping around the lower unit and bolted together.

My sense is that I would want to get the ride correct with the OB trimmed up at least a little. As Kevin points out I'd better be able to raise the bow especially when we get 20 knots out of the east running the Merimack inlet on a rising tide. Then, I'd need to be sure I won't cavitate...

Porkchunker, you may well be correct about running too fast. It may be I'm still use to the family boat and expect MV to be similar to old 24' heavy DV Sea Ray. But, in only about 1 ft. chop at about 22 kt I'd pound too hard unless I deploy tabs fully.

In flat-calm water, the end of my pulpit moves no more than about 4 inches vertical when tabs move from up to fully deployed.

Look-see here the pics. The end of a fully deployed tab is only about two inches below an imaginary parallel plane to the hull.

I made a mistake when the boat was new; I didn't demand sea trial and the seller was not very accomodating from day one. But I think she can be fixed to handle like her name-sake...Chop~Chop...

The postings here suggest Lenco 12x18 planes work well for 23xx. But I'm not convinced they are adequate for our 25xx beamier beasts.
Some sort of finite element analysis along with fluid dynamics could probably predict whether Lenco's 12x18 would work as well as Bennett's 9x24.

I was hoping to be in by Memorial Day too, but I got another dilema to deal with, not unlike the bottom paint issue I previously posted :x Sort of the dream that is my nightmare reality.

Dale, I'll try to catch up with you this weekend.

Mark

 

[susqking]

Chop Chop,
I wish you lived in the Chesapeake area, I have the same boat as yours and would love to show you the difference with the 9 x 24's. I was getting tired of pounding in a 1 to 2 ft chop. You won't regret putting them on, if you go that way.

good luck

 

[Chop~Chop]

susqking thanks for the offer. After I layup my boat around the beginning of October I'll be "free to move around the country" :wink:

Our season is sooo short my Admiral would move to your haunts in a heartbeat...

I figured out the thingy porkchunker uses is called a hydrfoil. I didn't find his posting with the stainless plates.

Here's a link http://sesport.com/5_29.asp
It must have been wishful thinking no drilling was needed :roll:

Now I'm overthinking again :?
IF I want to remove hyfrofoil after trim tab upgrade what would I do about holes in my anti-cavitation plate

 

[Megabyte]

IF I want to remove hyfrofoil after trim tab upgrade what would I do about holes in my anti-cavitation plate

J-B Weld :?:

 

[Porkchunker]

Chop,

Here is the link to my discussion about the plates: http://classicparker.com/phpBB2/viewtopic.php?t=228

Don't get the plastic "hydrofoil" type that bolt to the top of the anti-ventilation plate. Get the ones that bolt to the bottom. Permatrim and these Cobra plates are the only two I've found that bolt to the bottom.

The ones that bolt to the top or edge of the anti-ventilation plates, seem to stress the plates and can eventually cause cracking and breaking of the anti-ventilation plates. The plates that bolt to the bottom, use most of the surface area of the anti-ventilation plate to support the upward pressure.

I found the Cobra plates at Cabela's on-line catalog: http://www.cabelas.com/cabelas/en/templ ... hasJS=true

Don't get the painted ones...I did, and after two seasons the paint is gone exposing the SS anyway.

 

[Chop~Chop]

So after lots of consternation I've done something. I just hope it's not a big mistake and the sum of moments and forces remain zero.

If ya'll think I'll break something, like an actuator shredding the transom, please let me know.

I don't think the fully retracted position is too low; it may hinder how slow I can go and remain on plane but I believe this position had virtually no affect on bow position.

The fully deployed position looks a little aggressive; I'll certianly calibrate tab position to the little red LED bar-graph of the control rocker switch :wink:

 

[Porkchunker]

I think you are going to plow a lot of water and drop the bottom out of your mpg. And at $3.50-$4.00 a gal on the water, it won't take long to consume more $$$ than if you had gone to larger tabs.

Recommend you go with larger tabs or a Permatrim or the Cobra Marine plate I mentioned above.