Hi,

In previous threads, I've read that, even though the manual for the
velvet drive (w/ a perkins 4-108) can be freewheeled while sailing,
real experience proves this to be harmful and even catastrophic to the
tranny.

Some suggest that if the motor is started periodically (6-8 hours) then
the tranny will be ok.

Should we just plan on starting the motor every 6 hours and motor
sailing for twenty minutes before shutting the motor down?

or

Should we bite the bullet and buy a Maxprop?

---

Hey Glenn - while you're making a prop, maybe you could whip up one for
me too!

Thanks,

Mike.

I've heard that an engine start every two hours is necessary.

"beaufortnc" wrote in
ups.com:

In previous threads, I've read that, even though the manual for the
velvet drive (w/ a perkins 4-108) can be freewheeled while sailing,
real experience proves this to be harmful and even catastrophic to the
tranny.


I know of two transmissions for the 4-108. Lionheart has both of them, now
that we bought a used engine from a gent in NC that was swapped with the
8000+ hour 4-108 the boat came with.

Lionheart has a shaft alternator that puts out about 15A at 6-8 knots under
sail. So, it came with a different transmission that IS made to freewheel.
I'm sorry I don't have any numbers, but this transmission is quite larger
than the little transmission the newer engine came with. I'm not sure what
the internal differences are but the mechanic said the freewheeling
transmission is "hydraulic" instead of "mechanical", the smaller one. It
also has no shift clunk going from forward to reverse. The case of the
freewheeler is much taller and has an oval bulge vertically. Does anyone
out there have the numbers??

The freewheeler freewheels without damage for days at sea. The shaft turns
constantly at around 120 RPM with the shaft alternator load and the tranny
doesn't even get warm.

--
Larry

My manual says it´s ok the freewheel all the time
sg

"Steven Shelikoff" skrev i meddelandet
...
On 4 Oct 2005 17:20:15 -0700, "beaufortnc"
wrote:

Hi,

In previous threads, I've read that, even though the manual for the
velvet drive (w/ a perkins 4-108) can be freewheeled while sailing,
real experience proves this to be harmful and even catastrophic to the
tranny.

Some suggest that if the motor is started periodically (6-8 hours) then
the tranny will be ok.

Should we just plan on starting the motor every 6 hours and motor
sailing for twenty minutes before shutting the motor down?

or

Should we bite the bullet and buy a Maxprop?

The manual on my 4-108 with velvet drive said it had to be started every
8 hours of freewheeling. If you don't want to do that, either a
feathering prop or a shaft brake will do the trick.

Steve

Here is the reason for the gearbox failures associated with freewheeling. It
has nothing to do with the Velvet Drive specifically. It has everything to
do with hydraulic gears that operate on hydraulic oil pressure derived by
the engine only. In that light, lubrication is also provided by the engine.
Gear failures under freewheeling conditions are usually output thrust
bearing failures due to the lack of of lubrication and high bearing load. If
prop shaft thrust is low, shaft speed is slow and some lube is provided by
splash by the reduction gear, no damage will occur. Any deviation from the
above induces risk. You could alsodrive an auxillary pump off the shaft,
drawing oil from the gear sump and feeding an inlet port will also buy the
insurance you desire.
Steve
"beaufortnc" wrote in message
ups.com...
Hi,

In previous threads, I've read that, even though the manual for the
velvet drive (w/ a perkins 4-108) can be freewheeled while sailing,
real experience proves this to be harmful and even catastrophic to the
tranny.

Some suggest that if the motor is started periodically (6-8 hours) then
the tranny will be ok.

Should we just plan on starting the motor every 6 hours and motor
sailing for twenty minutes before shutting the motor down?

or

Should we bite the bullet and buy a Maxprop?

---

Hey Glenn - while you're making a prop, maybe you could whip up one for
me too!

Thanks,

Mike.

"beaufortnc" wrote:

Hi,

In previous threads, I've read that, even though the manual for the
velvet drive (w/ a perkins 4-108) can be freewheeled while sailing,
real experience proves this to be harmful and even catastrophic to the
tranny.

Some suggest that if the motor is started periodically (6-8 hours) then
the tranny will be ok.

Should we just plan on starting the motor every 6 hours and motor
sailing for twenty minutes before shutting the motor down?

or

Should we bite the bullet and buy a Maxprop?

We have a Perkins 4-154 and a velvet drive. We also have engine
driven refrigeration, which we run for about 35-40 minutes twice a
day. So with that in mind, the problem with free-wheeling didn't
really come up.

But the shaft turning was so NOISY that we hated it. It was as noisy
as living next to a freeway, and there wasn't any way to stop it
turning except to put vice grips on it (one of our sister ships did
that, but I didn't think it was a good idea). For that reason, we got
a Maxprop, and we really love it. Sailing is quiet again.

---

Hey Glenn - while you're making a prop, maybe you could whip up one for
me too!

Thanks,

Mike.

grandma Rosalie

S/V RosalieAnn, Leonardtown, MD
CSY 44 WO #156
http://home.mindspring.com/~gmbeasley/id1.html

I too have a 4-108 but with the 1.5:1 Paragon [P22L] hydraulic
transmission.

Is it safe from freewheeling 'cause it's hydraulic ?

Thanks,
Courtney


Larry wrote:
"beaufortnc" wrote in
ups.com:


In previous threads, I've read that, even though the manual for the
velvet drive (w/ a perkins 4-108) can be freewheeled while sailing,
real experience proves this to be harmful and even catastrophic to the
tranny.



I know of two transmissions for the 4-108. Lionheart has both of them, now
that we bought a used engine from a gent in NC that was swapped with the
8000+ hour 4-108 the boat came with.

Lionheart has a shaft alternator that puts out about 15A at 6-8 knots under
sail. So, it came with a different transmission that IS made to freewheel.
I'm sorry I don't have any numbers, but this transmission is quite larger
than the little transmission the newer engine came with. I'm not sure what
the internal differences are but the mechanic said the freewheeling
transmission is "hydraulic" instead of "mechanical", the smaller one. It
also has no shift clunk going from forward to reverse. The case of the
freewheeler is much taller and has an oval bulge vertically. Does anyone
out there have the numbers??

The freewheeler freewheels without damage for days at sea. The shaft turns
constantly at around 120 RPM with the shaft alternator load and the tranny
doesn't even get warm.

Courtney Thomas wrote in
link.net:

Is it safe from freewheeling 'cause it's hydraulic ?


I've seen so many conflicting reports on this thread, I'm no longer sure,
Courtney. I'm going digging into the bilge of Lionheart to find out what
transmission she has and read the book more carefully when I get there.
The transmission that's in there was in there when Geoffrey bought her and
it works fine for days without starting. I'll try to get its number when I
go down.

--
Larry