Catalina 34

General Activities => Main Message Board => Topic started by: Makani on February 28, 2011, 09:27:15 AM

Title: Propeller Diameter
Post by: Makani on February 28, 2011, 09:27:15 AM
I am getting ready to put a 14" diameter, 9 degree pitch feathering prop on my 34. Are there any negatives to this. I am trying to get more sailing speed for racing. Thanks.

Keith Gannett
Mt. Pleasant SC
Title: Re: Propeller Diameter
Post by: Ed Shankle on February 28, 2011, 10:12:30 AM
Don't think there are negatives, though if you check out some of the previous discussions on the forum, there are differing results on the best pitch. Factors to consider; number of blades, size of blades, size of engine (HP), tuned status of engine.
I put a 3 blade Flex o Fold on my 89 a couple of years ago with a 10 degree pitch. Works great; picked up 1.5 knots, combined with a new headsail. Seemingly improved my motoring speed as well. Pick up a knot there, although I also replaced the injectors too, so that contributed.
Others have found that a 10 pitch loads the engine too much. So it seems that depending on the factors above, it might be an iterative process to get the best setting for your boat.
Of course if your question was more around the impact to your rating, that's another discussion....

Ed
Title: Re: Propeller Diameter
Post by: Steve Sayian on February 28, 2011, 02:26:44 PM
Ed,

I'm just starting the job of replacing the injectors on my M-35.  Did you encounter any problems?  Did you have to have the new injectors adjusted for flow rate or do they just screw into the insert and then into the engiine.  What about bleeding them for the first time? Where's you get the new ones?

There's Kubota dealer in Norfolk, MA and I'm going to contact them for parts.

Steve
Title: Re: Propeller Diameter
Post by: Ron Hill on February 28, 2011, 05:53:42 PM
Keith : You didn't mention if the 14" prop was a 2 or 3 bladed??  FYI the factory installs 15" fixed props.

Title: Re: Propeller Diameter
Post by: Ron Hill on February 28, 2011, 05:59:39 PM
Steve : The flow rate of a diesel injector is fixed.  That's why you get the same number and manufacturer when you replace an injector.  Be sure you get the new gaskets when you buy those injectors.

If you'll read a couple of articles in the Mainsheet tech notes you'll find that changing injectors is an easy task.  a though
Title: Re: Propeller Diameter
Post by: Makani on March 01, 2011, 03:42:22 AM
It is a 2 blade feathering prop.
Title: Re: Propeller Diameter
Post by: Ralph Masters on March 01, 2011, 07:47:00 AM
If you're look to speed it up you're in the wrong type boat...............
Title: Re: Propeller Diameter
Post by: Ed Shankle on March 01, 2011, 11:26:42 AM
Steve,
Ron covered some of your questions regarding the injectors. To finish answering, at the risk of highjacking this thread;
Conveniently, there is a Kubota dealer in Ayer, 2 towns over from me (Bolton). I followed the usual bleeding procedure, it just took a little longer for the engine to fire up. No real problems, I followed the instructions posted in the tech notes/projects. However, there were a few things that I encountered that weren't covered in the instructions that I thought would be useful for those who haven't done this before and wants more detail. I passed them along to Stu to update the instructions. Mainly they were;
1. needed to take the valve cover off for the socket to sit over the injector
2. needed to loosen the rigid banjo lines in order to get at the injectors with the socket. also needed a closed end offset wrench to loosen the banjo nuts on the pump. Open end wouldn't fit.
3. there was a good amount of carbon powder around the edge of the injector that remained when I took the old one out. Used a vacuum with a long narrow attachment to suck it all out.
You may encounter different things as my engine is a m25xp.

Ed
Title: Re: Propeller Diameter
Post by: Ron Hill on March 01, 2011, 06:15:14 PM
Steve : Look at Ed's advice, but I never had to remove the valve cover and I doubt if you (M35 has smaller dia. injectors) will have to.

Sounds a though Ed had some "blow by" to have that much carbon.  Just remember that "Cleanliness is next to Godliness" when it come to changing injectors.  Wrench in one hand and the shop vac hose in the other.

Your injectors are a smaller size like I mentioned, so I can't give you any wrench sizes or other tips.

After you finish and torqued them down, don't forget to use the soapy water check with the engine running.  A little soapy water in the block injector well - and if you don't see any bubbles, you know the injector is seated and you have a good seal.

Not a difficult task !   :thumb: