Prop walk
Date: October 5, 2000
From: Lee McIntire llmac@wt.net
Paul,
I have a three bladed prop on my 77 E-32. The original Yanmar 2QM20 is installed in the boat. The prop walks badly to port in reverse. So badly that the engine is almost useless to slow the boat down in a tight canal or slip. As the boat slows, she also starts to rotate clockwise and the rudder cannot overcome the prop walk. I have to really be careful managing my energy when returning to a mooring. Fortunately my home slip faces into the wind.
The boat backs in a large circle to the left. Using short bursts of low rpm power provides some success when power departures from the slip are required. (wind from aft in slip). Most times I just push the boat out of the slip. Making way forward under power, the prop creates a great deal walk to starboard. The aft wants to swing right and the bow to port. I usually cruise at 1500 rpm and 5.5 kts with about 15 deg of right rudder deflection to hold course. Of course, turning left under power is just a matter of neutralizing the rudder and letting the walk run it's course. This is a big pain.
I believe the previous owner installed a prop that is just way to over pitched for this boat to cruise at a lower rpm. My mechanic has told me that the engine should cruise at about 2000 rpm for optimal performance and reduce wear. At 2000 rpm my prop cavitates and the boat makes 6.4 kts, but starts pitching down (and back up in oscillations of course).
I know that any prop mounted on an angled shaft will have some degree of "prop walk" This is a result of asymmetrical angles of attack on the blades as the prop moves through the water and an angle. The problem is worst at slow speeds and high rpm. This I understand, but I feel that my prop magnifies this normal phenomenon substantially. I have also been told that this prop is probably taking a half or full knot off of the boat's sail performance. Does anyone have any comments about performance with the original prop? Has anyone found a nice replacement / upgrade prop? I would sure like to hear from someone who has an idea. Thanks.
Date: Friday, October 6, 2000
From: Wayne Turk JANWAYNE@aol.com
I own an E-40 so the boats & props are different, however it is very important to have a prop that will allow the engine to reach it's rated rpm's at full throttle. Not only does it overload the engine & lug it down which is bad for diesels but it also does the same to the transmission. I can attest to that since I had a similar overpropped situation which cost me a new transmission. Consult your owners manual for max rpm & check it out.
Date: October 6, 2000
From: Dennis Jones dennisjones@rcsgroup.com
Lee,
I have a 1979 E-32 with the Yanmar 2QM20 and the original 2 bladed prop. The handling in reverse is much as you describe on your boat, though probably not to the same extent. The handling in forward seems to be OK, though. I also get cavitation when accelerating, but it seems to improve once the boat settles into the new speed.
I've read that the prop walk problem on these boats is a combination of the angle of the shaft (as you said) and also the small amount of clearance between the prop and the hull. If you refit, you might consider a smaller diameter prop.
I've learned to use the prop walk to good advantage in most cases. The boat will spin on her keel in almost her own length. When leaving the slip, I use a fairly high rev to get some reverse momentum and then put it in neutral. Once clear of the pilings, I put it in reverse and it walks the stern around and points me out the channel. On return, I coast into the slip and then use reverse to walk the stern over where I can pick up my spring line, then use a little forward to push the bow over to the finger pier. Of course, if the wind is blowing, none of the above applies. Good luck!
Date: October 6, 2000
From: Bob and Sandy Warren rwarren@inna.net
I've got a 79 Endeavour 32 with the same engine as you but a 12 x 16 two bladed prop which I believe is the original. We walk to the left also when backing down but nearly as badly as you from what you describe. When going forward the boat will turn if you let go of the helm but I wouldn't say the off-setting force one applies to the helm is unreasonable.
I was interested in your comments because when we made the transition from one-design sailing and racing to cruising we were surprised at how much we have had to use the motor. We were thinking that changing to a three-bladed prop would be more efficient and perhaps work better when backing up the boat. Now I think I'll let sleeping dogs lay!
Date: October 7, 2000
From: Paul Uhl endvr32@endeavourowners.com
Bob,
A 3-blade can make it worse. The only solution I've heard about is to switch to a feathering prop. It virtually eliminates it. It has more to do with the fact that a propeller is only efficient rotating in one direction (forward) and the blade tends to grab or pull more water in the other (reverse). A feathering prop minimizes that.
Date: October 7, 2000
From: Kevin Coon kkcoon@worldnet.att.net
Hi Lee,
I started with a 3 blade prop. Best motoring sailboat I ever saw. It sailed really badly with that prop. I could only back straight at 1000 RPM or less. It helped a lot to push the boat backward out of the slip to get it moving and to let the rudder get a bite on the water.
Then I went to a fixed two blade, motoring was good, sailing was like a different boat. Backing was a little better.
Then I went to a folding prop. I will never use a fixed prop again! It sails like a different boat all over again. Backing is ok, still have to start out low RPM to let the rudder get a bite. Motoring is fine, I put a bigger diameter folder on than the fixed since it didn't drag.
I cruise at about 2300, usually. It gets pretty close to hull speed there even with a little chop.
I would love to try a feathering three blade. The only problem I have found withthem on other boats is that they snag a lot of seaweed and lobster traps. Hope this helps.
Date: October 8, 2000
From: Bradd Wilson marina@portcolborne.com
We had the same problem with prop walk due in large part to the 3 blade prop and configuration of the keel to rudder space ( the prop grabs as much water from the side as it does from ahead). This and the huge drag from the 3-blade prop under sail convinced us to look at folding or feathering props. We settled on a Flex-o- Fold 2 blade cruising model and reduced prop walk significantly although not completely and really improved sailing speed. Cost is around $1000.00 but it makes a world of difference and has the added benefit of not catching crab/lobster traps.
Date: October 8, 2000
From: Ed Phillips EPhil49932@aol.com
There was a recent email to the forum regarding a 3 blade prop on an Endvr 32, the lack of response when backing to starboard, or, trying to slow the boat down using reverse, and keeping the boat straight. This reminded me of an email I received several months back from a member who had measured the prop area on his E-37, and felt the Max-Prop would not fit. I can't remember who at this point, but, thought I'd share the following.
Im finally back in the water after a 15 month (weekends, vacations, and hollidays) total refit on my E-37. The refit included a 3 blade Max-Prop, cutlass bearing, and new prop shaft due to some "galling". The Max-Prop fits and it works well. I can back to starboard, and stop straight in a very short distance. It takes practice, however, and getting use to how much power to crank in at the right time is challenging at first.
There is still some port prop walk due to the rotation, but the blade angle mitigates the worst of it, and a burst of power will send you to starboard. Starting rudder position is very critical in the equation.
I do not know if the Max-Prop will fit on the E-32, but would probley help alot.
My boat is faster under power now, but this could be due to the new Yanmar as it has more horsepower than the old 4-108, and I do not know if the greater horsepower is a factor in how the Max-Prop functions.
As far as the galling on the shaft, it was in the cutlass bearing area, and I was given the following reason for why it happend. . . (I do not know for sure that it's all correct, but, the boat builder who pointed it out is very highly thought of, and it makes good sense)...He says that the prop shaft length from the strut to the prop is a bit long, and the torque/pressure of the three blade prop caused the shaft to "wobble" inside the strut.
The Max-Prop fits differently, the weight is quite a bit closer to the strut. There is a very distinct smoothness to the boat now. . . a lack of vibration at all speeds. Some of it is due to the new motor, but I think the new prop should get some of the credit too.
The down side of course is the cost of the prop.
Date: October 9, 2000
From: Ed Blithe BLITHE@Sensormatic.com
Lee, on Invicta 1978, 32, and original 2QM20, we installed this year, a three blade 16 X 10 RH, and we've been satisfied with it. We removed the original two blade due to poor performance. We can back up much better than with the two blade, however given the angle of the shaft we also walk, but to starboard. We do not experience the pitching that you mentioned and we can cruise along nicely at 2000, about 5.7 knots. (depending on how much junk we have on the speed wheel). We purchase the prop from Frank And Jimmie's Propeller shop here in Fort Lauderdale, P) 954-467-7723, just in case ya would want to contact them. Good Luck
Date: October 10, 2000
From: Ed Blithe BLITHE@Sensormatic.com
Lee, when I purchased my three blade prop the shop had a software programwhich took vessel weight, engine hp, etc and produced the pitch. Also, theyshowed me how to determine a RH from a LH but it would be impossible for me to explain it. (something about how you can pick it up with the blades facing you etc). There wasn't any stamp on the new prop we purchased.
Anyway good luck with the haul out. We too had a "grounding" we hit a rock with the front portion of the keel. It put a gash about 15" long and about " deep. I used underwater epoxy and it worked so well we continued the vacation. When we hauled it 7 months later, I just needed to sand it and it was ok. That was about 2 years ago and there isn't any evidence of water intrusion in the glass. So far so good. Good Sailing
Date: October 9, 2000
From: Lee McIntire llmac@wt.net
Hi all,
Many thanks to all of you for the email sharing your experiences and providing advice. We are having out E-32 quick hauled on the 21st for her annual inspection / cleaning. Usually this just involves a pressure wash and check of the bronze through-hulls, cutlass bearing, thrust bearing, rudder ect,; then a re-launch back into the water. (a few weeks ago we experienced a soft grounding. i didn't find any damage when i dove and inspected the keel and hull in the slip, but nothing beats a direct eyeball of the hull on the lift)
After hearing from all of you I believe I am certainly going to re-install the original prop I found in the lazarette. This may prove to also be unsatisfactory, but even if so, experiencing the difference will be a good education. Especially since we already have the prop and the boat is being hauled anyway.
Does anyone know how to determine a prop's specs? I believe the first number is the diameter, is the second number an indication of the prop's pitch? (ie: 16x10 RH) How do you determine the pitch by examining the prop? A look at the direction of pitch indicates RH or LH rotation. If its stamped on the prop somewhere I am missing it.
Thanks again! Its great having a community of fellow Endeavour owners to help with these types of issues. Happy Sailing
Date: October 10, 2000
From: Bradd Wilson marina@portcolborne.com
The first number is Diameter; measure from center of hub to the outside edge of ONE blade then double it. The second number is pitch which should be stamped on the hub. Figuring it out from looking at it is tough since it is the distance the "screw" would travel when turned one revolution. The direction is easily determined by the "prop walk". When you put the boat in reverse, does it walk to port or starboard. If it pulls left, it's a Right Hand and if it pulls to the right, it's a Left Hand. You can also tell by observing the prop from inside the boat when motoring. The other dimension you'll need id the shaft diameter which can also be measured from inside the boat at the rear of the engine.
Date: October 10, 2000
From: Tom Gilbert TGil95746@aol.com
You can measure the diameter of the prop by placing it on a flat surface and use a small tee square on the blade edges to mark the flat surface and then measure the marks. You can spin the prop to get marks directly across from each other.
To get the pitch, just stand the prop up on a blade and walk the blade along the surface until you have gone one revolution. Keep the shaft centerline straight ahead. Draw parallel lines from the beginning and the end and measure the distance. Or, just look at the numbers on the dang thing!
Date: October 11, 2000
From: Paul Uhl endvr32@endeavourowners.com
Lee,
Glad to help. You might also want to look at the Pratical Sailor article "Max-Prop vs. Autoprop" in the May 1, 2000 issue (back cover) which compares the virtues of a feathering and folding prop. If you don't have it I can fax it to you.
Date: October 11, 2000
From: Bill Lowenberg lastdance@pocketmail.com
I've had grat success with a prop built for low rpm engines (sailboats) called "sailprop" check with larger prop shops. Cost $400. and worth it. Final test. record max RPM in neutral, max RPM in fwd. should be within 5 percent.
Date: October 31, 2000
From: Doug Martin DOUGANDJILLMARTIN@prodigy.net
I have what I believe is the original 2 blade prop and have the same problem especailly when backing. Using short bursts of engagement of reverse rather than leaving it engaged in reverse the entire time backing seems to help. I wish I could help with a solution. Let me know if you find a good one. I have my wife pull in on the bow line to swing the stern to starboard before backing to adapt to the walk.
Date: November 2, 2000
From: Paul Uhl endvr32@endeavourowners.com
Doug,
The only REAL solution for prop walk is to get a feathering prop. Prop walk is caused by the fact that a fixed blade prop is NOT symmetrical (forward vs reverse), that's why they have "right hand" and left hand" props--each of which will create prop walk in the opposite direction of their rotation. Feathering props are symmetrical and although they don't "grab" as quickly as a fixed blade, will virtually eliminate prop walk. A horizontal prop shaft will also reduce the effect but a feathering prop goes a lot further in eliminating the problem.
Owners I've spoken with that have gone to a feathering prop say prop walk is entirely elimanted.
Date: January 12, 2006
From: Paul McGirr paul@chfcorp.com
I put on a Max Prop, feathering prop when I purchased our 1978 E32 a year ago. Unfortunately the prop walk in reverse is horrific. I have tried every imaginable way of backing the boat our of our slip but to no avail. As soon as we go in reverse the boat wants to rotate to port in a clockwise motion. Unfortunately this has me pointed a 180 degrees in the wrong direction. If my slip was facing in the opposite direction the prop walk would work for me.
Until I can get a new slip, I will back the boat out manually with dock lines and continue to embarrass myself.
But I noticed in the Forum under the suject of Prop Walk, your last comment was that owners who have gone to a feathering prop have all but eliminated their prop walk. That being the case does anyone have an explanation for my dilemma. I would appreciate any help I can get on this subject
Date: January 12, 2006
From: Wolfgang Harms Wolfgang@pioneer-research.com
I have had a Max Prop for over 10 years and I am very satisfied. More powerful in reverse than my regular prop. There is no difference in the "prop walk" between other boats, other props, and my present prop. I suggest to check the pitch. The Max Prop company might help you. Their manager's name is Kevin. I think they are in Seattle. Call them up, but have your model, size and pitch setting.
There are ways to deal with normal prop wash, as you probably know and have tried. I give it a kick, and immediately turn into neutral before the boat has a chance to turn, but then drift slowly back out of the slip. Then the rudder will work. Once out, if you have enough room accellerate, and once in higher speed, the rudder will overcome the prop wash. If not enough room, do the kick-and-neutral method. In extreme cases, I have done a total 270 degree, with the propwash. If wind, current and propwash work against you, I have used a pivoting line. There are probably more tricks.
Plastic bags and debris wrapped around the prop can have bad effects, even prevent the prop from folding in the right position. Also a damaged prop. Another cause can be the shape of the hull, for example if some fiberglass repair was done that changed the water flow.
Date: January 12, 2006
From: Bruce Kemper BAPCKemper@aol.com
Hi Guys, Bruce Kemper here . . . I'm a yacht broker with Gulf Coast Yacht Sales as well as former Endeavour (1983 E- 40) owner. I've had the opportunity to run any number of boats and prop combos . . . several with Max Props. Every boat I've run that had a Max Props was neutral in reverse and forward. Did you change the pitch or diameter of the prop when you made the change? When you shift from reverse to forward do you hear or feel the prop reverse? Has the prop been inspected by a diver to make sure it's operating correctly? If you increased the size of your prop you'll have a vibration in reverse or forward . . . do you hear or feel that? If the prop is even 10% closer to the hull than the original prop it will defeat the reversing capacity of the prop. Hope this helps.
Date: January 12, 2006
From: Peter Hoeltje boatskipper@hotmail.com
Your going to get it with a feathering prop..they are nice, but not for cruising boats. Since they feater, when they are in reverse they remain kind of flat so it will give severe pull to that side and considerably less efficient when in R. Also its one more thing to jam or fail when you least want it to(and they do from time too time). My advice would be to replace it with a regular one and maintain manuverability of the boat. Its in tight quarters you want the control. The minimal walk you will get with the regular prop can be an advantage when docking once you get it figured out. I have spun ny 43 around on a dime and backed her straight into some TIGHT spots and left crowds amazed. ITs all in the comfort. Also dont be afraid of making weigh in reverse. Once you get some boat speed in her, she should drive like a car while coasting in neutral once you are backing.....again you need to be comfortable and confident with handleing the boat.
Date: January 12, 2006
From: Robert Lightbourn RLightb240@aol.com
Possibly You may be able to adjust the amount of pitch (lessen it in reverse) that should help. Sounds life its taking too big of a bite.
Date: January 12, 2006
From: Sandy Grima sgrima@gis.net
Although we had a geared folding prop we did find a few things out that we would like to pass along. On a windy day all bets are off and the boat will go with the pervailing wind. Backing out of the slip apply just enough power to get the boat moving with out over powering. The more power the more port prop walk. Once the boat is moving back off the power as much as possible to the point of putting it netural. This will reduce the port prop walk and transfer the steering control back to the rudder, which is overpowered by the prop walk. The other thing that is helpful when backing out of a slip is to guide the boat back as straight as possible for as long as possible using as much slip as a walk way. Once you have cleared the slip and are moving back in a straight line use reverse power sparingly (again more power = more port prop walk) also use as much real estate behind you as possible with our runing into anything behind you, given that you will have to stop the reverse monentium and get the boat moving forward enough to transfer steering control to the rudder going forward.
If you find this does not work there is always the use of a midship cleate to spring the boat to the right but that is a whole other story. Hope this helps and let us know how you make out.
Date: January 12, 2006
From: Barton Pokras bartonpokras@yahoo.com
We have a feathering prop on our E43 and we definitively have prop walk. Also, when sailing (not motoring) we put the transmission "in gear" to stop the prop from turning the propeller shaft.
Date: March 15, 2006
From: David Glasser agavedave@msn.com
I went from a 3-blade fixed to a 2 blade folding Martec (on my E32). What a mistake. The cocktails are pre-mixed by the engine on the way to the mooring, but I can't drink them because my teeth hurt from the pounding. The Martec 17 cleared the hull and rudder with a little room to spare. I traded down a size to a 16 inch in hopes of a smoother ride. The prop fits fine, but the vibration is still horrible. Hope this helps.
