Prop selection

[Pilotocopilot]

The previous previous owner of our 37 re-powered the boat putting in a 3HM35 Yanmar in her. Nothing else changed so the 1 " shaft is still there etc.
My question is, is the shaft tapered at the prop end and what's the typical prop for this combination, diameter and pitch,with rotation I'm guessing at right hand.
Now the reason for asking, I've come across some folding props locally that may or may not be suitable, their shaft size corresponds but since the boat is 1500 miles from where I am diving on it with a tape measure is impossible to get at least the diameter.

 

[Johnb]

I can answer part of it. My HC 37 had a 1" shaft with an SAE taper on the end. The nut that holds the prop on is 3/4".

If you know the brand of prop you can submit the boat weight, engine HP at X rpm and transmission ratio to the prop dealer and they will advise you of the suitability.

 

[Jim Legere]

The original prop was a 15RH16 two blade. Here is an old thread discussing prop options: http://forums.hunter.sailboatowners.com/showthread.php?t=112561

 

[Ed Schenck]

Anyone who has called Flex-O-Fold has gotten the right answer. Loved my two-blade with the 2QM20 and now the three-blade on the 3YM30. Still have the two.

 

[Pilotocopilot]

After going to the link you provided Jim, I noticed one of the comments was to provide the prop shop the necessary info including the clearance which if anyone knows is pretty much the last piece of the puzzle I'll need.

 

[Ed Schenck]

In this thread( http://forums.hunter.sailboatowners.com/showthread.php?p=614830&highlight=prop clearance ) you can see a picture of my unfolded 16 x 11 Flex-O-Fold. With an 8" blade you still see that there is lots of room. The rule, I think, is that the space between the blade and the hull should be at least 15% of the diameter. Or in the case of my 16" prop a clearance of 2.4".

 

[Pilotocopilot]

Thanks everyone, I've decided I have to go down to see it and deal with a rear main seal leak on the trans anyhow, so I'll get the pertinent info when she gets hauled out. I'm sitting on the fence as to bothering with a folding prop as the number of issues re comming off throwing blades constant maintenance poor performance as indicated on some of the other forums I've been reading have turned me off somewhat.What I do want to investigate is whether my current fixed prop is sized right as one thing I've noticed is the motors inability to reach it's peak rpm and the props rear prop walk is the shits.

 

[Jim Legere]

I'm sitting on the fence as to bothering with a folding prop as the number of issues re comming off throwing blades constant maintenance poor performance as indicated on some of the other forums I've been reading have turned me off somewhat.

Maybe what you need is a feathering prop rather than a folding prop? I think if you want to spend the bucks, MaxProp, J Prop and others will do the job. Kiwiprops are cheaper and I have heard good reports on them too. Me? I have stuck with my old 2-blade fixed and I put up with the 'exciting' propwalk

 

[Pilotocopilot]

Jim I think your right, live with the prop walk. But I still may have an issue with it maybe being too much prop and not allowing the motor to achieve its max rpm. The only other thing I'll get them to check is the Tach, nothing saying it may not have a flat spot.

 

[Jim Legere]

If the problem is "too much prop", its pretty easy (and inexpensive) to have a prop re-pitched.