Help & ideas for easy steering Vietnamese style longtail engine / prop (to heavy operation)

[SokSanManagement]

Over weighted long tail prop/shaft.
Looking for ideas & suggestions please.
I have a team installing a Vietnamese style long tail engine and mount on a wooden river boat (see photos). Currently the system is to heavy for single person operation and I would like possible simple solutions that do not require the entire unit to be welded again or engine reposition or changing length of prop shift. Are there any more simple solutions that can make the weight balance easy for one person to lift and steer that does not require major changes to the set up/mount?
The engine is a modified medium size car engine on a customer welded mount with a 4.3m prop shaft. I believe the location of the engine should be fine but the prop shaft and prop are overweight making lifting and steering very very hard work.
Any possible solutions would be helpful for us to consider before we have to go back and start again with the mount sizing and weight distribution or relocation of the engine itself on the mount.
Thank you anyone for help.

 

[portacruise]

Put a long tapered cylindrical float as a collar surrounding the submerged portion of the long propeller shaft so the flotation pushes upward? Requires experimenting to see how large it has to be to give sufficient flotation.

Replace the propeller shaft with another shaft that is lighter, if the existing one is already way too strong? A hollowed out pipe, or solid aluminum, or titanium shaft?

Only other simple thing I can think of is to use an adjustable stop on the hinge extending towards the propeller shaft end, but the downside is that it keeps the propeller from going deep, requires that you be able to make something that adjusts quickly?

 

[BlueBell]

So many options.

A gas shock that takes some of the off balance load, or a spring or bungee cord.

A foot pedal with mechanical advantage so that when you push down on it, it compensates for the imbalance.

A counterweight on the front of the engine.

An adjustable AoA whale tail on the prop shaft that drives the shaft up when making way.

Just a few ideas that may work on their own or in combination.

However, rebuilding the mount would be your best option.

Good luck!

 

[seasquirt]

Move the pivot closer to the prop., or move the engine further forward on its mounting frame. Then no extra weight from extra equipment.

 

[kapnD]

The pivot point must be altered to balance.
Unhealthy handling characteristics will result if imbalanced, and control will be difficult.

 

[Adler]

Try to extend the end point of the triangular support frame along the propeller shaft , closer to the propeller hub ; that way you will increase the buoyancy (static condition) near to the end mass (propeller's mass) of the mechanism and you also receive an uplift force at the shaft end point when the boat runs (dynamic response).

 

[BlueBell]

@SokSanManagement

I missed the second most obvious solution:

Extend the lever arm length forward. Do you have room / space?

 

[gonzo]

A spring or rubber bands attached to a point below the pivot.