"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