Trim tabs with twin engines?

Rokjok777 · Posted: Sun Dec 14, 2003 4:09 pm Post subject: Trim tabs with twin engines?

Hi, I'm sold on the benefits of tabs, but Squidward has twin Honda 50's and there wouldn't be much space between the tab and the engine. I'm thinking about the Lenco 9X12. Should I be looking at narrower tabs? Or are tabs a no-no with twin engines? Also, let's hear some unbiased opinions on whether the hydraulic or electric tabs are better...I'd like to mount the control unit in one of the lazarettes and don't want the hassle of topping off fluid...plus those hydro hoses do seem to add to the maintenance. Any opinions?

C-Hawk · Posted: Sun Dec 14, 2003 9:47 pm Post subject:

I just installed the Bennet trim tabs-- Sport 80's with the auto controller. Have yet to get them wet, but SEA3PO has them and work great. Yes, we have twins.

Almas Only · Posted: Mon Dec 15, 2003 7:15 am Post subject:

Don't know about clearance for twins, but have installed the Lenco 9X12's on our 22' CDory, and am very pleased with the installation and operation. Photos of the install are posted under the Trim Tab Photo Album, under the most creative heading of "Trim Tabs". I'll be glad to give you a measurement on the spacing between the units, if you want, and take a stab at any of your installation questions, if you go with this unit. Like others, I've found trim tabs to be a "must have" piece of equipment, which only take a little while, and some open water, to master.

Good luck!

Almas Only · Posted: Mon Dec 15, 2003 7:30 am Post subject:

As a followup on Lenco 9X12, we got our's new, in the box, delivered to the front door, for $386. I'll be glad to share particulars, if you're interested.

MOOSE · Posted: Mon Dec 15, 2003 8:04 am Post subject:

I installed the Bennett M-120s Sport Tabs on our CD22 last spring and we have twin Honda 40s. The installation was straightforward, they work well, and I would not be without them.

Alyssa Jean · Posted: Mon Dec 15, 2003 8:18 am Post subject:

I also have twin Honda 40's and had Les at EQ Marine install the Bennet tabs. The larger tabs can not be installed because of the limited remaining space to the outside of the engines, but the smaller ones fit fine. You will love them and wonder how you got along with out them.

There is also a thread on the old C-brat MSN Tech site with a lot of discussion about tabs.

Les Lampman · Posted: Mon Dec 15, 2003 10:23 am Post subject:

rokjok777,

I highly recommend trim tabs (and I do like the idea of the Lenco's enough that we'll put them on our current boat); I believe everyone that's installed tabs has been quite pleased with the results.

The M120 Bennett tabs that are typically installed on the twin engined CD22's have a 10" span and a 12" chord. These fit well but I wouldn't push the chord any wider; it's tight enough at 10" that I've had to remove previously installed hydrofoils (like Doel-fins) in order to avoid interference at full lock turns (particularly when tilting the engines).

You've got to be careful on the sizing charts; the tab manufacturers are not consistent in the order of which the span and chord is given; a Bennett 12x9 is 12" in width (span) and 9" in length (chord) but a Lenco 12x9 is just the opposite at 12" in length (chord) and 9" in width (span).

My experience suggests that anything from 80 square inches (per tab) up will work but my preference is for something over 100 square inches. In the Lenco line I would opt for the TT12x9E for a twin engine CD22 and the TT9x12 for a CD22 with a single engine. The TT12x9E tabs will mount just fine on a single engine boat but the 12" chord is going to cause problems if you've got a kicker motor mounted on the transom next to the main engine; the kicker won't clear the 12" deep (chord) tabs.

Rokjok777

This is one of the many reasons I chose a C-Dory, this great online resource for information. Thank you all. Really superb, now I have a winter project. Lenco TT12 x 9E are my choice, thanks especially to Les.

Iconoclast · Posted: Mon Dec 15, 2003 1:15 pm Post subject:

Can't you all get most of the benefits of trim tabs by just tweaking the engine angles? What more do you get?

jimandlaurie · Posted: Mon Dec 15, 2003 1:16 pm Post subject:

Our Christmas present to Laurna Jo is tabs. But it may take a bit cuz we gotta wait for Les( The Premier Dealer and C-Dory Rigger!) to slow down a bit with all the "births" he is taking care of. Will go with his recommendation.
Jim

MOOSE · Posted: Mon Dec 15, 2003 2:55 pm Post subject:

"Tweaking the engine angles" will only serve to raise the bow more; i.e. they only "tweak" one way. To limit pounding, the nose must be trimmed down and the best way to do that is with tabs. I would not be without them.

TyBoo · Posted: Mon Dec 15, 2003 8:36 pm Post subject:

C-Hawk · Posted: Mon Dec 15, 2003 11:51 pm Post subject:

"Can't you all get most of the benefits of trim tabs by just tweaking the engine angles? What more do you get?"

Yes, you can get a little attitude adjustment by "tweaking" the engines. But you lose performance when you do. I have the twin Honda 40s with the hydrofoils and have been able to adjust for list and attitude by raising one engine more than the other. This is not the best way to maintain good performance. I just installed the Bennet M80 sport-tabs. I would have gone with the M120, but I would have had to remove my bait pump.

Les Lampman · Posted: Tue Dec 16, 2003 8:57 am Post subject:

Roger,

That's a perfect example of a good compromise! Sometimes in these posts things come across as more "absolutes" than they really are; we're always trying to choose the best item possible but sometimes (really most times) the best choice is the one that gets the job done while not disrupting the other things about the boat one likes.

Did you keep the hydrofoils when you installed the tabs?

C-Hawk · Posted: Thu Dec 18, 2003 1:22 am Post subject:

Les-
I left the hydrofoils on for the time being. They clear the trim tabs by a couple inches.
The main reason for getting the trim tabs was for the side to side attitude. With the refrigerator on the port side, the boat was always listing to port. As noted above, I adjusted for it by trimming the engines separately- it took most, but not all, of the list out. I will be at Lake Cachuma for the next couple weeks, and will make adjustments and set the auto trim then.
With the limited dash space, I made a small shelf for the trim tab rocker controls just forward of the engine controls and mounted the auto control just left of the wheel. I will try to remember to take a couple of pictures.