Prop Data

[Mike Vaccaro]

Hi Folks!

There has been quite a bit of activity recently on the C34 board regarding various propellers that owners have installed in place of the factory-provided Michigan Wheel fixed pitch bronze props.  I'd be interested to hear from any owners who have swapped their stock wheel for a different fixed pitch prop, or a feathering or folding prop.  I would like to gather specific information about various installations so that we can compile a database of different prop options based on real-world experience. 

Based on engine, a forward pitch range of 9 (approximately 18-degrees) to 11" (approximately 22-degrees) with a 15" diameter is fairly "nominal" for the Catalina 34, with most folks favoring the 9-10" pitch range.   

For the data to be useful, we'll need to know the hull number, type of engine, type of propeller, prop dimensions and blade settings (pitch).  If there are specifics, e.g., the x/y letter calibration system used by PYI Max props, please include that as well.  Any performance notes, installation or maintenance tips would also be appreciated.   

Depending on the amount of data received, we'll either publish a short article in the Mainsheet (or tabulate the data) to make it easy to compare different wheel options for the C34.   You can simply add to this message thread, drop an e-mail to my address on the officer's page, or you can use the private message function to get in touch. 

Cheers,

Mike Vaccaro
C34 Association Tech Editor

[sail4dale]

some initial data for your reseach:

MK II (#1582) fin keel, West. 35 B engine, std rig, Flexifold 3 blade folding prop.
15" x 10 pitch  boat loaded for cruising no tracing mode.

Max practical RPM at engine: 2450;  Tach reads =/- 1900 RPM
Boat speed in smooth water and clean bottom - 7 - 7.4 knots

[Steve S.]

MK I - Tall Rig with shoal keel and MX-25B engine.  I have the Flex-o-fold 9 x 15.  It cruises at about 6.--6.5 knots on smooth water at about 2200 rpm

[Jeff_McKinney]

MK II wing keel, standard rig, Westerbeke MX-35B engine

Gori 3 blade folding prop 15 x 9, avg cruising RPM 2200-2300 on a clean bottom and 1-2 foot seas = 6-6.2 kts SOG. NO prop walk in reverse makes backing a lot easier.

[John Langford]

Mk 11, #1431, deep keel, Universal M35BC

Kiwi 3 blade feathering Prop, 15"x20degrees. Straight forward installation, requires greasing and painting of blades and hub when hauled. 6.6 knots at 2200rpm with clean bottom. Superb backing control. Huge improvement over Michigan wheel especially in light air. About $1300US delivered to your door.

[Steve Sayian]

MK II #1448, std rig, wing.  Kiwi feathering, same as Calypso.
Factory set at 21 degrees.  Too mutch pitch.  Engine smokes and lost 500 RPMs. 
Going to re-pitch to 10 inches (19 degrees).

In 10 knots or less boat performs exceptionally well.  It actually 'ghosts' again!