[C320-list] RPM Vs SOG

[warren updike]

I have the original two blade prop and get between 5.5 and 6.0 SOG depending
on conditions at 26-2700rpm. I rarely run over 3K except for short spurts.
Temp is always between 175 and 190. Cooler in the spring and fall, warmer in
the summer when the bay water reaches 80F.  

Last year I used the optical tach from the C320 Tool Box to calibrate my
tach so I'm confident it's reasonably accurate. In comparing responses to
your query, take into consideration that tachs as well as temp gages may
vary widely.

Warren & Pattie Updike
Catalina 320, #62, "Warr De Mar"
Middle River, Chesapeake Bay




-----Original Message-----
I have an adjustable pitch MARTEC 3 blade feathering prop. and am trying to
decide if its pitched correctly and how well it performs.  I can get the
RPM's up to 3400 under full power and achieve 6.8 knts SOG under calm sea
and weather conditions.  At 2700 RPMs I'm doing about 5.4 knts.  3000 gets
me to about 5.9.  How's that compare with others.  My temp gauge reads
exactly 180 degs. at 2700 and rises just over the 180 deg mark when I push
it to 3200 but seems to hold.
 
Thanks,
 
Joe Tamucci #619