Shafts thru the transom?

[tom kane]

An average marine workshop could easily build an inboard/Vdrive that could be run as a conventional drive,or as a drive that can be raised and lowered from horizontal or down 20 degrees shaft angle,or much more using mass produced components.You could have a choice of surface piercing or subsurface drive,and a choice of steering devices.Take a look at James R. Wynne 1960 inboard outboard patent and see how that works.There are many other systems used in modern applications.The cost should be minimal, even as one off units.

[JBAInnovationAS]

Like the one on the attached picture. Made form available standard universal joints etc. only the big nylon pivot and axle tube are machined, ... and of course it didn't work. Disasterous geometry and flow to the propeller. I am now building a traditional shaft/ submerged propeller setup on this boat. Will let you know speeds etc. when I am done.

[tom kane]

Originally Posted by JBAInnovationAS

Like the one on the attached picture. Made form available standard universal joints etc. only the big nylon pivot and axle tube are machined, ... and of course it didn't work. Disasterous geometry and flow to the propeller. I am now building a traditional shaft/ submerged propeller setup on this boat. Will let you know speeds etc. when I am done.

Looking forward to see this project.

[Steve H]

Here is a better pic of my current set up that is coming out any day. just waiting for the weather to warm up

Steve H

[tom kane]

Thanks for the better image Steve H don`t we have fun,the things we do.

[CaptPPan]

I have almost the same setup on a 27' Harley. What size shaft do you use and how long is it. I've also had to force feed my stuffing box with water to keep it from burnig up, did you have the same problem?

[Steve H]

The shafts are 1 1/2". The are about 70" overall length. Yes I did run water pressure lines from the engine blocks to the stuffing boxes. I just drilled and tapped the shaft log assy and installed a barbed fitting, then connected a 3/8" line from the exhaust manifold. Made a huge difference. It also has water pick up tubes that are bolted to the transom, pointed into the shaft exit holes. I had to tighten the stuffing box constantly prior to the waterline install. Other than dock handling, this has been my main complaint about this set up.

Steve H

[CaptPPan]

I handled my stuffing box problem the same way and now it works wonderfully. I'm only using an 1 1/4 shaft and it's almost as long since my engine is mounted under the centerconsole. I get alittle shaft wipp on exceleration so I plan to upsize the shaft when I reprop.

[Steve H]

I tried to use a dripless packing, but the shaft whip issue destroyed it in no time. Had to go back to standard stuffing boxes.

Steve H

[tom kane]

These S/P propellers with side plate rudders on Albert Hickman`s 20 ft Viper1V 6 cylinder 25 HP Ferro engine may appear to have water flow problems,the sea sled had a shallow V flatting at past midships through to the transom,and the sea sled gave good speed with the heavy machinery of the time.Power Boat Speed by Kevin Desmond.

[Frosty]

I bought a brand new cat and did just that I literally stuck 2 shafts out of the transom about 16 inches away, bought surface props 24x 24 and drove them with a pair of Yanmar 6 LPwith zf 630A down 8 degree gear boxes. My wieght is 14 tons and I can achieve 24 kts but cruise all day at 3000 RPM 16 kts. It is very smooth no vibration and use 45 liters per hour at 16 kts

[CaptPPan]

Jack,
Sounds like a nice boat, can you post some Pictures?

[Frosty]

Hi Capt
I new some one would ask me that hmmm i do have some but are of the boat when I bought her in aus. I know you want to see the drives. I am not very good at this, will get my buddy to help me --stand by - might take a day or two.

[Frosty]

Ok I got to send you .Hope they come through. One is of the boat leaving Aus on a ship to Singapore. The other is just of the drive only. The rudder at that time was experimental. There has been three since then!!

[CaptPPan]

What a nice symple system. Is it comercialy availabel or did you make it up?
Is there a conventional stuffing box on the inside of do you keep the water out some other way?