Long distance towing - Page 2

FoxZulu · 17 May 2018, 08:36

I always tow with the engine tilted fully up as it puts the weight of the power head above and forward of the transom rather than behind where it would be trying to lever the transom off.

Last Tango · 17 May 2018, 12:13

Mid-way with a custom block fitted to the ram for me.

The engine is off-balance when it's fully tilted and puts a lot of strain on the steering. Also if you've got a hard boat I'm guessing it has an engine well that'll mean your control cables /rigging tube will probably be getting pinched a bit when it's fully tilted.

Also leg sticks out further....more vulnerable and liable to hurt someone if they walk into it.

Just my preference.

Pikey Dave · 17 May 2018, 13:40

Quote:

Originally Posted by FoxZulu

I always tow with the engine tilted fully up as it puts the weight of the power head above and forward of the transom rather than behind where it would be trying to lever the transom off.

I'd say from a mechanical forces point of view, the higher the engine the higher the stresses on the transom. When the engine is vertical, most of the weight is in vertical shear on the transom, the more you raise it, the more leverage you apply to the transom. With the engine fully tilted, you have created a see-saw on the transom. Look at it this way, if you wanted to prise the transom off, would you put a bar vertically on the transom & try & pry it off by pulling out the top of the bar, or would you fix a bar horizontally to the transom along the keel line & put your weight on one end?
Just my opinion.

charliee · 17 May 2018, 14:08

Several outboard manufacturers sell OEM versions of My Wedge - Home
I've use a couple of different models for different engines and they don't need a lot of tilt to activate the support, therefore I assume its best not to tilt the engine higher than necessary to clear any obstacles you might encounter on the road also the Lower an engine sits the greater support provided by the engine bracket.

FoxZulu · 17 May 2018, 15:35

Most of the weight of an outboard is at the top in the power head. With the OB tilted down ALL of the weight of the OB is trying to move downwards behind the transom thus creating a levering force on the transom. Now imagine that the OB is positioned one metre further to the rear of, and still attached to, the transom. The twisting force would be much amplified.
By tilting the OB 'up' you are moving the majority of the weight forward, as well as slightly downwards, placing it above and to the front of the transom, and so reducing the twisting effect on the transom. It is also now above the rigid structure that the transom is supported by. It also has the benefit of placing more weight within the actual boat thus shortening the overall weight/length ratio and giving a more favourable CoG for towing. Providing that the OB is locked in this position there will be no see-saw effect.

IMO I doubt it makes much difference at all as the boat has been designed and built to carry the weight in any position. I just think that if you're going to tilt the engine at all you may just as well put it in the most advantageous position available.

All in my opinion, of course

Last Tango · 17 May 2018, 17:09

Quote:

Originally Posted by FoxZulu

....By tilting the OB 'up' you are moving the majority of the weight forward, as well as slightly downwards, placing it above and to the front of the transom, and so reducing the twisting effect on the transom.....

This would be the case if the pivot point was central, right in line with, and on top of the transom, but it's forward of the transom like and off-set hinge so the engine actually rises as it's tilted and moves further away from the transom increasing it's leverage.
Remember it's not the vertical weight that's the devil here, it's the inertia created by it's mass and if the transom can withstand the beating it takes coming off a 2 meter wave with half a ton of thrust from the prop hitting it, a couple of pot holes in the road shouldn't be of any concern IMO.

MatFromPoland · 17 May 2018, 20:33

But some engines are designed to tow a little up like Evinrude:

If you not trust your transom on towing maybe not go to the Sea ??

Pikey Dave · 17 May 2018, 20:41

Quote:

Originally Posted by MatFromPoland

But some engines are designed to tow a little up like Evinrude:

If you not trust your transom on towing maybe not go to the Sea ??

Evinrudes have the best setup for towing imo. I was shocked when I went to the dark side after owning evinrudes & found that I'd to start sticking a lump of wood in the engine, it was a step back.