23 Seacraft Twin Outboard Alignment

Skeeter15 · #1 08-08-2016, 01:33 PM

Hello All,
I am the owner of a 1983 model 23 Seacraft with Hermco bracket running twin Suzuki DF140's. Initially they were toed in at the front of the lower units about 3/4 inch. The motors were ventilating in turns and in chop. I have since toed them out 1/4 inch and the boat handles better and ventilation was significantly reduced. My bracket has 30'setback. My lower units are about 40' from the bottom of the transom at neutral trim. Can anyone running a similar set up comment on how their motors are toed (in...out...or straight)? Any feedback is appreciated!

natecert · #2 08-09-2016, 06:33 AM

Owned a 27.6 Rambo w/twin 150 Loopers and they were not toed in or out. They were hung on the transom don't know if that has any impact. In calm to lite chop I could leave the helm do a two minute chore and return, still on coarse.
Good luck
Ed

flyingfrizzle · #3 08-09-2016, 07:25 AM

Some will say toe out drops the bow and toe in lifts the bow and you will get many different responses on this if you read around on the performance sites. There are many variables that come into play here. I have personally been told to tow in the front of the noses an 1/16-1/8" to get best ride or performance. Some will argue that and say turn them opposite so the thrust lines meet 30-50 ft behind the boat. If you talk to the "go fast guys" they will tell you to set them for least drag at parallel or slightly in as torque thrust will pull them back parallel. I also have read and been told to un hook the cross bar and run them where they want to go for best ride and set them where you boat handles best. Also I think it depends on how you set the motors up, counter rotating inward for bow lift (most don't do) or outwards (how most are setup with the counter rotator on the port side). I personally think trying different things to see how your boat responds will get you the best response as no two boats do the same. Start parallel and check to see if they torque in or out and adjust to see how the boat responds. Get it set where you have the best feel and less drag as possible. I know if you go excessive either way toe in or out you will get blow out so starting parallel or slightly toe in is where I would begin. Asking suzukie for their suggestions in your case would be a good ideal too. 3/4" seems like a whole lot.

Skeeter15 · #4 08-09-2016, 10:40 PM

Thank you for the feedback. My props rotate outward. I will move the lower units back toward parallel looking for the sweet spot. Disconnecting the cross bar did not work on my boat. The loose engine would turn inward approximately 1 inch and ventilate like crazy. Boat had difficulty planing. I think it is because there is a hull transition directly in front of the lower units causing them to act a little different. The boat performs well with the slight toe-out. Just trying to maximize efficiency. Thanks.

Fr. Frank · #5 08-10-2016, 10:14 PM

Because your motors rotate outward at the top of the arc (as I understood you to say) you will need a very slight amount of toe-in to prevent heavy-side steering dominance. The mount of toe-in required is based upon arcane math involving a triangle from the average point of entry for the hull and the points of thrust and the distance between the points of thrust. I don't get that math.

I do know that if you have any toe-out, your motors are fighting/thrusting against each other in a turn. As with a car, the inside prop (wheel) travels a shorter forward distance through the same degrees of arc, and so must turn more sharply. This is accomplished by toe-in.
But 3/4" is too much, of that I'm sure.

NoBones · #6 08-10-2016, 11:40 PM

Quote:

Originally Posted by Skeeter15

My bracket has 30'setback.

30 feet !!!

40 feet above the transom..

No wonder the damn thing has issues......

DonV · #7 08-11-2016, 07:49 AM

Yeah, cavitation might be an issue.

I'd drop it to 39' and see if that helps.

Skeeter15 · #8 08-15-2016, 11:18 PM

Frank-
I plan to toe in slightly and see what happens. Thanks for the input.

medic1227 · #9 12-13-2016, 10:13 PM

I run twin 175 optimax's on a 30 inch bracket. I run them with no toe in or out, I do run them a little deeper than I like because of the great hole shot and no problems in a snotty sea condition.

gofastsandman · #10 12-13-2016, 10:44 PM

Quote:

Originally Posted by flyingfrizzle

Some will say toe out drops the bow and toe in lifts the bow and you will get many different responses on this if you read around on the performance sites. There are many variables that come into play here. I have personally been told to tow in the front of the noses an 1/16-1/8" to get best ride or performance. Some will argue that and say turn them opposite so the thrust lines meet 30-50 ft behind the boat. If you talk to the "go fast guys" they will tell you to set them for least drag at parallel or slightly in as torque thrust will pull them back parallel. I also have read and been told to un hook the cross bar and run them where they want to go for best ride and set them where you boat handles best. Also I think it depends on how you set the motors up, counter rotating inward for bow lift (most don't do) or outwards (how most are setup with the counter rotator on the port side). I personally think trying different things to see how your boat responds will get you the best response as no two boats do the same. Start parallel and check to see if they torque in or out and adjust to see how the boat responds. Get it set where you have the best feel and less drag as possible. I know if you go excessive either way toe in or out you will get blow out so starting parallel or slightly toe in is where I would begin. Asking suzukie for their suggestions in your case would be a good ideal too. 3/4" seems like a whole lot.

You make many great points.

What are you looking for OP?