now a prop question

[Jeff Kaplan]

As per my earlier posts, I need a new prop, not a transmission. The damaged prop was a composite 2 blade 15 1/2X9, going now for a bronze. After reading many threads on this forum, it seems that the earlier C34's with the 21 hp Universal M25 w/Hurst 50, boat came with either a 2 or 3 blade prop 15X9 with 9* pitch. I know that the 2 blade creates less drag but the 3 blade gives a little more umph when needed. When looking on line, seems 3 blade is less money and money now is of concern.  Looking for suggestions, need to go to H&H prop tomorrow. Thanks...Jeff

[Noah]

There is much about the debate between the Campbell Sailer and the Michigan Wheel Sailor. Both are good fixed three-blade props. Some say 15x10 others 15x9, either will work. My boat (25XP) 23hp and Hurth 50, came with A Michigan Wheel 15x9. I "upgraded" to a 3-blade Flexofold 15x10 folding prop.

[Jeff Kaplan]

Thanks Noah, I'll see if H&H has the original 15X9

[Ed Shankle]

Jeff, I echo Noah's comments. Had a 3 blade fixed, pitched to 10, then later on got a Flexofold 3 blade. Both sail and motor speed increased. There is, or was, a dealer in Marblehead who I ordered from and installed myself.
If lowest cost is the main driver, I'd go 3 blade fixed, just for the extra torque in rough water.

Regards,
Ed

[scgunner]

Jeff,

This is one of those topics that can be debated endlessly, ask 10 guys what's the right prop to use and you'll get 10 different answers and probably none of them wrong. The original prop was installed by the guys who build the boat to provide good all around performance, and it does. However individual sailors will have different and specific needs which may make a prop switch desirable. Someone who sails mostly will probably want a different prop than someone who motors mostly.

You'll need to figure out what type of sailor you are before you start prop shopping. Keep in mind even if you get the exact right prop for you your performance will only be incremental, in other words there's no prop out there that will enable a C34 to motor at 10 knots.

[Jeff Kaplan]

Guys,  I spoke to Gerry Douglas at Catalina this morning to ask him whether a 2 blade or 3 blade came standard on the early 34's, could have been either but he said most came with 2 blade.   If anyone in the future wants to know, the 3 blade is a 15X9 and the 2 blade is a 15X10. I went to prop shop today, and am waiting for response on price and availability. Gerry suggested the 2 blade for less drag when sailing, stated 3 blade gave a little more push. Price will determine.  Thanks for all responses...Jeff

[Ron Hill]

Jeff : Most of the C34 owners with a 3 bladed fixed (sailor) 15"x9" prop have re-pitched to 15"X10"!!

A thought

[Jeff Kaplan]

Ron,  I went with Gerry's suggestion of a 2 blade 15X10 fixed prop. He was fairly certain that the 2 blade was original on the boat. The boat came with a 2 blade composite prop and it worked well for me for 16 years, so I went that way, only now in bronze. Should have it early next week, will have a short haul, R&R and be back in action for weekend of 18th. This weekend in Salem supposed to rain, so no big loss.

[Noah]

2 blade is better than 1-1/2 blades!

[Jeff Kaplan]

Noah, that is quite right, actually the prop ended up being 1 blade.

[TortolaTim]

I just got a quote from West By North for a new prop. Mainesail recommends this particular brand and manufacturer. I sent them my boat info and here is the recommendation he sent me. I had read extensively on this site about the great prop debate and saw that the consensus was 15x10. They however, are recommending a 13x9. Below is the e-mail I just received from the company. Any thoughts?


"Hi Timothy,

Thank you for your interest in the Campbell Sailer propeller.

This recommendation assumes the Catalina 34 on the Universal M-25XP engine (23hp @ 3200 RPM). We're also assuming a Hurth HBW-50 transmission with a ratio of 2.05 to 1. Shaft diameter is 1.0 inch.

Based on this I would suggest a 3 blade RH 13.0" diameter x 9.0" pitch (13x9). This size is recommended to give you a good cruising rpm and still have reserve for head wind and seas.

The Campbell Sailer has cupped blades and a leading edge foil. This produces greater thrust and reduces the slip rate. To account for this we often size smaller than other manufacturers for a given installation.

The Campbell Sailer offers the perfect balance between powering, maneuvering and low drag performance. It's the lowest drag fixed 3 blade on the market. Up to 35-40% less drag when compared to equivalent size units from other manufacturers. The Campbell prop is renown for how smooth it runs throughout the entire RPM range.

This is a benchmarked installation for us. Last customer on the Catalina 34 / M-25XP @ 2.05 was very happy with the 13x9 Campbell Sailer prop. He could get 3200 RPM at max and a boat speed of 6.5kts cruising at 2700 RPM.

We would be happy to discuss this recommendation in further detail or answer any questions you may have."

[Jeff Kaplan]

Tim,  I assume Cambell knows what's best, but, I went with the suggestion given to me by Gerry Douglas, Catalinas chief designer. The 15X9 3 blade or the 15X10 2 blade which he suggested and I got. 13" seems very small but the cupping probably makes up for the size. The 3 blade provides a little more thrust but the 2 blade causes less drag while under sail, for what it's worth.  The decision is yours to make.

[Noah]

All interesting info. Can either/both of you share the cost of these various prop options? Also Jeff is the prop you ordered a Michigan Wheel or???

[Jeff Kaplan]

Noah, 2 blade 15X10 cost $600-, don't think it is Michigan wheel, they are much cheaper. I did see cheaper on line with 6-7 week lead time, can't wait that long. I know H&H propeller is a renowned shop so I know I am getting a quality prop, bored out and balanced correctly. I should have prop next week, at that time I will post what mfg. it is.

[Noah]

Jeff, unless they have your shaft in the shop you/yard should lap fit prop to your shaft when installing prop. Mainesail's web site (compass Marine How to) has good instructions on how to do this. It is not hard to do. You will need some dye and emory paper. Good learning exercise.