A need for speed

[Tom]

We have a 1989 Hunter 30, and love it. However, we have her loaded for coastal cruising and would like more speed for the long motor runs against the current. We have a 2 cyl, 18 hp Yanmar, and displace around 11000 lb. As far as I know, the prop is the original bronze 2 blade. We are a low budget program. Any suggestions?

 

[Steve Dion]

Contact Kilian Prop in San Leandro, CA.

Tom:Contact Kilian Prop in San Leandro, CA. These guys do wonders with fixed blade props. It is worth a call to them just to see if they think they can help you.

 

[Dean Strong]

3 bladed prop

Switch to a 3 bladed prop. I did, and the boat runs at hull speed at just under 3000 rpm, cruises at 6 knots at 2800. The engine also seems to run smoother, and backs 100% better.Check out the February (?) and March issues of Sail magazine on props, particularly three bladed props. A three bladed prop more than doubles the surface area and thrust.I was told that I would loose about .5 knots sailing, and a 5 degrees pointing, but I haven't noticed any difference. Of course I don't race either.Cost was about $300, plus a ten minute haul out to replace the prop. Any good prop shop can give you the proper size, or you can use the Sail article, which has tables and formulas. E-mail me if you want more info.

 

[Ron Sheldon]

Need for Speed...?just push!

RSIn regard to your question and the responses gotten. I would have to say..Go for the 3-blade prop. If you were racing and trying to get the maximum from your boat then go for a feathering 2 blade or have them "Tweek" your old one for the best pitch etc. I have had 3 boats over the last 10 years. (an 84 Ericson 28+, 85 Islander 30' & 34 Hunter) at worst case you lose about 1/2 a knot..(really...that is all!!)I actually checked in similar conditions with a GPS. But the added push you will have is amazing!! & add to that the torque in reverse?...My gosh. On the Ericson I had a folding prop and we used to really bury the railings. But motoring we sometimes joked we could get out and push faster. After going to a 3-blade...you could feel the difference and as far as sailing you really couldnt feel much differance.(I felt more drag with a dirty bottom!)the only way to really tell was by checking the GPS while heeling.If you give a prop shop your HP and rated RPM & hull speed/shaft size. you can go with the recommended prop size/pitch and get a used or re-conditioned (ie balanced)prop for about $150 or less!) So I would do it..as a matter of fact I did...3 times!!Good luck and great sailing (and motoring!)RS

 

[Kevin l. Woody]

Need for HP

Hello Tom,1st Your running gear is as only as efficient as your propeller. 2nd Your propeller will only distribute as much torque as your motor is capable of producing. I believe two things are going on with you. Your current two blade should be replaced to a three blade unit. This will increase the propellers end by as much as 30%. It may not increase the speed drastically but it will allow the boat to power into a heavy wind or sea without as much speed loss like your current two blade. The motor output needs to increase. I would look over the motor to make sure you are not having a problem with?? Which could reduce the motors ability producing its rated output. A fixed three blade will cost apx. $300 ish and a new motor $$$$.$$ I would try a new three blade first. Good luck Kevin.