Experience with Campbell Sailor propeller on a Hunter 36

[PNWE36]

Hello,
I have read positive posts on the Campbell Sailor propeller in the forum. I am interested in hearing about experience from someone who has installed one on a Hunter 36 or a sailboat with similar engine/transmission combination.
My 2011 H36 has a Yanmar 3YM30 engine with a Kanzaki KM2P-1 transmission 2.62 ratio. The stock propeller is a 3 blade 15x12 pitch. I am looking to replace it and West by North is suggesting a 16x9. They said they have supplied this propeller for several H36 but do not have any customer feedback to reference.
I have a slight vibration (pulse) at the helm above 2000 RPM. It is worse under load. My boat only has 280 hrs on it. I have done all the usual things to eliminate vibration. Everything from the transmission coupler back has been removed and checked or replaced and aligned. There is minimal vibration at the engine/transmission. I did have the propeller balanced as well but maybe it is still out of balance.
I want to change the propeller to see if it makes a difference and may as well get some benefit in the process. All information I can find shows the Campbell sailor is a good choice for a fixed propeller. I want to avoid going through a process of installing the propeller and then having to send it out to have the pitch changed if it is not correct.

Thanks,
Dirk

 

[jssailem]

Dirk.
I just read again your posts about the vibration.
From the descriptions, it sounds like you significantly reduced the issue at the motor, shaft, cutlass bearing (it’s condition likely due, at least in part, to the misalignment you repaired), and coupler. It sounds like the second alignment did as good as possible - 0.001 on the coupler. I learned when I replaced my shaft and coupler that you want to assure the shaft and coupler are “Fit & Faced” This means the shaft is at a 90º angle to the face of the coupler. That way as you attach it to the transmission and align the engine/transmission/shaft it will be centered in the cutlass bearing. Then the only last element it to assure the prop is fitted to the shaft and aligned. The taper on the shaft and the taper in the prop hub when married should complete the desired alignment.

Soft mounts can be an issue, but not the issue you describe. “Vibration at the Helm”.

My suspicion is you are getting cavitation when the prop is spinning. Cavitation will affect the rudder. You would feel it in the helm.

My experience with WestbyNorth was excellent. I talked a lot to the engineer when ordering my prop. I have a 35f boat displacing 16500 lbs, with a 48hp diesel and a 2.6 transmission ratio. Not a Hunter.

You need to know the distance from the bottom of the hull at the prop to the shaft for WbyN to get the correct prop size. If you have the room for the 16” prop that is great. As I recall you need about 2” of space between the prop blade and the bottom of the hull so as not to have cavitation as the blade rotates compressing the water against the hull. (That is from memory. The engineer at WbyN will know.)

The design of the blade was a significant element in the improved thrust generated by the CampbellSailor prop.

You might also consider the distance from the prop to the rudder. To close and cavitation off the spinning prop can cause a vibration as the fluid passes across the rudder.

 

[PNWE36]

Hello John,
Thank you for your reply. I am confident the coupler etc has been assembled properly. Not sure about the propeller as it has not been double checked. That will be done with the propeller change.
The rudder is several feet from the propeller I can't say for sure but would expect the cavitation would have been absorbed into the surrounding water by then.
WbyN have been very good through the quotation process. I don't have the measurement from the blade to the hull and the boat is in the water. From the pictures WbyN said there "should" be enough clearance plus they have supplied this size of propeller for other H36 without any negative feedback. It looks like more than 2".
Cheers,
Dirk

 

[jssailem]

This is the prop I took off in 2018.
Bad design flaws that made this a bad Prop on my boat.

Here is what the Campbell Sailor looked like coming out of the box in 2018.

Here is the prop in 2023. Just out of the water, when I did the shaft replacement, the rebuild of my engine and transmission.

Looks good for being in the water for 5 years.
The design gives me more forward thrust without dragging the stern down or overloading the engine. Yields improved performance.

 

[PNWE36]

Thanks for the pics. Looks good after 5 years.

 

[FastOlson]

Watch out for common "assumptions" too. I once bought a new name-brand prop that, when checked, was not matched in pitch for all blades. A few $ later, and it was.
True for the compromise prop that came from the OEM. "Trust but verify" as the saying goes.