Capn Chuck wrote:
SD, It does depend on the RPMs of your engine, however, PYI is going to recommend at the least a tube connected to the dripless, vented above the waterline and left open to the air. This allows the system to burp itself and purge air. The water line is an easy install if you decide to go that route. Chuck
*It's usually not about RPM...as the range of most boat engine rpm*isnt that extreme..it's about boat speed and whether higher speeds would draw water out of the stuffing tube to the point of lessening cooling.
Here's a couple statements from installation manuals/articles..
15A. Low speed boats
Under 12 knots of boat speed under power).
Note:Sailboats or displacement powerboats with a powering speed below 12 knots can use either method A or B.
Using a 3/8
A dripless seal must be constantly
cooled by water. In low speed applications
(under about 12 knots) water pressure i
the stern tube is sufficient, but most models
have a hose barb in the seal housing for
injecting cooling water
-- Edited by psneeld on Wednesday 16th of November 2011 07:16:43 AM