I am building a 18" barrelback runabout. Instaed of the standard
straight-shaft inboard drive, I am considering a modified I/O setup.
I would purchase a used Mercuiser 3.0L I/O. The engine would be
installed in the center of the boat as is normal for this type of boat
and is required for proper balance. The outdrive would be installed
on the transom. The driveshaft of the motor would be attached to the
outdrive with an extended drive shaft (torque tube), about 4' long.
Has anyone ever seen this done? Any comments or suggestions are
appreciated.

That is very common, I would make up a shaft assy. from a automotive drive
shaft out of a bone yard, but that would not be my first choice. My first
choice would be a Z drive. That would position the engine and prop in the
right place and maintain the clean transom that all barrelbacks should have.
Steve
"Bruce Taber" wrote in message
om...
I am building a 18" barrelback runabout. Instaed of the standard
straight-shaft inboard drive, I am considering a modified I/O setup.
I would purchase a used Mercuiser 3.0L I/O. The engine would be
installed in the center of the boat as is normal for this type of boat
and is required for proper balance. The outdrive would be installed
on the transom. The driveshaft of the motor would be attached to the
outdrive with an extended drive shaft (torque tube), about 4' long.
Has anyone ever seen this done? Any comments or suggestions are
appreciated.

(Bruce Taber) wrote in message . com...
I am building a 18" barrelback runabout. Instaed of the standard
straight-shaft inboard drive, I am considering a modified I/O setup.
I would purchase a used Mercuiser 3.0L I/O. The engine would be
installed in the center of the boat as is normal for this type of boat
and is required for proper balance. The outdrive would be installed
on the transom. The driveshaft of the motor would be attached to the
outdrive with an extended drive shaft (torque tube), about 4' long.
Has anyone ever seen this done? Any comments or suggestions are
appreciated.

Centaflex make a series of shafts/rubber couplings that do exactly
what you want to do. AGM series. I'm doing exactly the same with an
8 ft 5 inch hollow shaft. Hollow shafts have the advantage that
longer lengths can be used without a support bearing.

On 11 Sep 2004 23:21:49 -0700, (Rob) wrote:

(Bruce Taber) wrote in message . com...
I am building a 18" barrelback runabout. Instaed of the standard
straight-shaft inboard drive, I am considering a modified I/O setup.
I would purchase a used Mercuiser 3.0L I/O. The engine would be
installed in the center of the boat as is normal for this type of boat
and is required for proper balance. The outdrive would be installed
on the transom. The driveshaft of the motor would be attached to the
outdrive with an extended drive shaft (torque tube), about 4' long.
Has anyone ever seen this done? Any comments or suggestions are
appreciated.

Centaflex make a series of shafts/rubber couplings that do exactly
what you want to do. AGM series. I'm doing exactly the same with an
8 ft 5 inch hollow shaft. Hollow shafts have the advantage that
longer lengths can be used without a support bearing.

Get a brochure via this URL:
http://www.engineeringtalk.com/news/cen/cen107.html

Brian W
- no beneficial relation

Do you know any classic mahogany power boat plans source?
Thanks

Steve, What do you mean by a Z drive? I thought a Z drive was a
British term for an outdrive unit. I stated that I was planning to
put an outdrive on my transom but you state that a Z drive would be
better because it would maintain the clean transom look. I'm
confused.

"Steve Lusardi" wrote in message ...
That is very common, I would make up a shaft assy. from a automotive drive
shaft out of a bone yard, but that would not be my first choice. My first
choice would be a Z drive. That would position the engine and prop in the
right place and maintain the clean transom that all barrelbacks should have.
Steve
"Bruce Taber" wrote in message
om...
I am building a 18" barrelback runabout. Instaed of the standard
straight-shaft inboard drive, I am considering a modified I/O setup.
I would purchase a used Mercuiser 3.0L I/O. The engine would be
installed in the center of the boat as is normal for this type of boat
and is required for proper balance. The outdrive would be installed
on the transom. The driveshaft of the motor would be attached to the
outdrive with an extended drive shaft (torque tube), about 4' long.
Has anyone ever seen this done? Any comments or suggestions are
appreciated.