cv or u joints
 

Hello all.
I was wondering if anyone has any knowledge about installing an engine
15* different from prop. shaft. I'm hoping to drop the engine down
into the pilot house sole, so it's level. I'm considering "U" joints
or CV joints, or other alternatives that might prove better. I'm open
to any input. Thanks, Paul.

Paul Baker wrote:
Hello all.
I was wondering if anyone has any knowledge about installing an engine
15* different from prop. shaft. I'm hoping to drop the engine down
into the pilot house sole, so it's level. I'm considering "U" joints
or CV joints, or other alternatives that might prove better. I'm open
to any input. Thanks, Paul.

Check out AquaDrive.

Lew

I don't think Aqua Drives can get more than 7-8 degrees out without
excessive wear.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

"Lew Hodgett" wrote in message
...
Paul Baker wrote:
Hello all.
I was wondering if anyone has any knowledge about installing an engine
15* different from prop. shaft. I'm hoping to drop the engine down
into the pilot house sole, so it's level. I'm considering "U" joints
or CV joints, or other alternatives that might prove better. I'm open
to any input. Thanks, Paul.

Check out AquaDrive.

Lew

Paul Baker wrote:

Hello all.
I was wondering if anyone has any knowledge about installing an engine
15* different from prop. shaft. I'm hoping to drop the engine down
into the pilot house sole, so it's level. I'm considering "U" joints
or CV joints, or other alternatives that might prove better. I'm open
to any input. Thanks, Paul.


If your present engine is 15 degrees down and taking shaft thrust load,
your solution may be a new marine gear with an output shaft at a down
angle. If you find a joint that will take the angle, it probably will
not also take the thrust so an external bearing will be needed on a new
structure.

In both cases, you might be best off running your idea past a marine
architect or surveyor before spending effort at the change. When you
want to sell the boat, the surveyor will likely catch risky design if
there is any in the drive or engine bed and it will be too late to fix
it even if it has not broken while you own her...

Skip

Paul,
Glen is correct. One set of CV joints will handle about 8 degrees without to
much wear. Universal joints at that angle will create to much velocity
modulation and create a pounding noise when running. However, it is possible
to get 15 degrees of angle successfully. I have done this on my boat, but I
used an oil cooled thrust bearing at the end of the prop shaft. I then used
2 automotive rear axle CV joints from a 7 series BMW. The end of the second
shaft has a spline which mates to a modified BMW differential housing, which
is mounted into a watertight bulkhead in sheet rubber (for noise). The spool
inside was stripped of gears and locked. The diff is only acting as an
intermediate shaft bearing. The engine is connected to the diff, on the
other side of the bulkhead, through 2 BMW CV joints and splined shaft end in
a similar manner as the second shaft. So, in final assembly, I have 3 shafts
and 4 CV joints and 2 sliding splines absorbing about 15 degrees of angle.
This allows the engine to be shock mounted to the keel, as the engine and
gear no longer has to support shaft thrust. Automotive CV joints cannot
handle thrust. The Aqua - drive units do.
Steve

"Paul Baker" wrote in message
om...
Hello all.
I was wondering if anyone has any knowledge about installing an engine
15* different from prop. shaft. I'm hoping to drop the engine down
into the pilot house sole, so it's level. I'm considering "U" joints
or CV joints, or other alternatives that might prove better. I'm open
to any input. Thanks, Paul.

"Paul Baker" writes:

Hello all.
I was wondering if anyone has any knowledge about installing an engine
15* different from prop. shaft.
snip

You are describing my installation.

It is accomplished with an AquaDrive (Actually a pair of CV joints on a
common shaft)which handles 10 degrees and an offset TwinDisc
transmission which handles another 10 degrees of down pitch.

It is understood that the engine must be pitched down with the tranny
end of the engine below the PTO end, not the other way around.

To the best of my knowledge, 10 degrees is the maximum down pitch most
engine manufacturers will allow.

HTH

Lew