Your most frequently asked questions… answered.
Editor’s notes (2019)
The FAQ and discussion below has been mildly edited to eliminate typos, make it clearer who the authors are and which boats they themselves have (by hull number and boat name if known). Wherever possible alternative (i.e. current) references to products & suppliers are provided.
The bulk of this FAQ was originally generated as a Q&A in the period 2005 – 2015. In this period Lester Helmus acted as a clearing house for questions and responses, but some respondents would also write direct to each other, hence some of the overlapping answers you see in the FAQ. In places there are 2019 and subsequent comments, drawing either on my own experiences, or from other Corbin 39 owners and sources, including our Corbin 39 Group on Facebook. More comments are most welcome and this FAQ will inevitably grow.
We have attempted to contact all contributors to the 2015 version of the FAQ. All responses have been most supportive, thank you. If you are a contributor who has yet to respond please contact us.
As will be apparent there are multiple viewpoints on some topics. Sometimes, but not always, this can be traced to differences in arrangement between the boats of the various authors. Some of the topics raised are not so much a Q&A, as simply being a statement of why a particular owner thought something was a good idea, which of course it may not have been at all. Make your own mind up.
If you have further comments or suggestions on any of these questions, or wish to pose new questions, or describe various issues you have faced and/or overcome, then please contact us either via the Facebook Group or via the Website.
[Remark as of November 2019: Quite a lot of the links to drawings & photos are not yet reinstated due to workload. However I also know quite a few of the relevant images have gone astray. You may find the relevant photos in the individual boat’s entry. Please email us if you have any of the missing photos, drawings, etc.]
ENGINE and SHAFT and PROPELLOR
Our engine started to blow blue smoke and used quite a bit of oil. Considering the cost of overhaul and the ” under power ” issues, we will be re powering to something larger over the winter. I would appreciate some input as to what would fit into the boat and what is suitable for this size of boat, preferably with same footprint. I can go longer but not much wider than the present engine. Existing: Vetus M 414, 33 HP c/w Hurth HBW 150V gearbox. Thanks for your prompt reply, the engine is 50% under the steps. The bed is long, however I can’t go much more in width without putting the chainsaw to the woodwork, e.g. Yanmar 50 HP would be a bit too wide. What do you know / think of the new line of Volvo, it looks as if the 50 HP Volvo is very close to the Vetus M 4.14 in foot print, and bear in mind that I MUST stay with the V Drive set up. Any engine with less than 3600 rpm, I would not be able to use our HWB 150 V box ( 3:1) and would need the whole new package. Preliminary pricing here in Canada is +/- $15K, I would install myself, less any trade in value. Regards, Frank Bryant (s/v #186, Visitant)
The engine is 50% under the steps. The bed is long and I can’t go much more in width without putting the chainsaw to the woodwork. Eg. Yanmar 50 HP would be a bit too wide. What do you know / think of the new line of Volvo, it looks as if the 50 HP Volvo is very close to the Vetus M 4.14 in foot print, and bear in mind that I MUST stay with the V Drive set up. Any engine with less than 3600 rpm, I would not be able to use our HWB 150 V box ( 3:1) and would need the whole new package. Preliminary pricing here in Canada is +/- 15K, I would install myself, less any trade in value. Regards, Frank Bryant (s/v #186, Visitant). P.S. I hear that Westerbeke is a Mitsubishi just like our Vetus. Any thoughts on West. ???
a. I’ve just purchased a refurbished Pathfinder engine from Pathfinder Marine in Montreal. These people are amazing! If you want ANY information on changing things on your engine call John at 1-514-695-6676. He’ll answer any questions and supply original parts. They’re still in business, and going strong. With the engine comes an original Pathfinder engine handbook (250 pages!) with all part #’s and repair instructions. They are also offering a deal on new engines and will take your old one on trade. Call John, he’s really knowledgeable and helpful. Paul Melanson (on s/v #058, Quintana)
b. Thanks for the lead to Beta Marine. After talking to numerous wheelers & dealers representing various engine makes the Beta people were very prompt, knowledgeable, accommodating and VERY competitive in pricing. Needless to say, I have a deal for a new BV2203 ( 50 HP ) in the works with a c/w gearbox. [This is the engine Collin Harty is planning to use with Galene.] By the way, I also spoke to the Pathfinder people in Montreal, Canada, saw their new engine in a Corbin here in Toronto, heard and felt it run etc. The Pathfinder has NO association with VW whatsoever. The price quoted was Plus / Plus / Plus etc. and they wanted me to do the deal NOW and they were doing me a favour by ” welcoming me to the Pathfinder family ” and were overly critical of every other make out there. SPOOKY, I thought. Regards, Frank Bryant, (s/v #186, Visitant) hull #186.
Advice requested. Asked by Jeremy Parrett (#101, Two Pelicans (ex #101, Pelican 1 / Two Pelicans) )
a. Hi Jeremy, I have a Pathfinder 50 engine, rated at 42 HP. It drives through a 2.77 gearbox ratio, with a 1 1/4″ shaft. Normal max engine rpm is about 3000-3500. Originally I used a Gori 2 blade folding propeller, 16.5″dia x 11″ pitch. It worked OK, even in reverse, but maximum speed was only about 6 knots. I have now fitted a fixed 3 blade prop 3bladeprop.jpg and I BELIEVE it is 18″ dia x 11″ pitch but I can’t locate the reference details. The blade tip clearance is about 2″ from the hull . I have a prop strut that I designed myself, offset to port so that the prop shaft can be withdrawn to miss the skeg. It may be different from your strut My shaft slope is 1.375″ per foot, according to my sketches made long ago. I had my prop shaft and propellers machined so that the Gori can still be used on the same shaft, as a spare. Speed at max rpm is now over 7 knots, with great acceleration. Of course the 3 blade prop gives significant drag while sailing compared to the Gori and I have to lock the gear in reverse to stop it spinning while sailing. There are different opinions on this procedure but the one I go by is that there is insufficient splash lubrication of the gearbox at the revs caused by the prop windmilling.
David Salter (#050, Opportunity)
b. (May 15, 2013) This response might be a bit late to be of much use to you but here is my experience with Autoprop… “#155, Blue Run” has a Westerbeke W58 with a Hurth V-drive transmission (15 degree down angle). Engine under the companionway steps. I installed an 18″ Autoprop in 2006. Under flat water no wind conditions we get 6.5 knots at about 1800 rpm. At 2100 rpm (the engines torque peak) we will make 7+. With wind we lose about a knot and with waves in the 3 to 4 foot range about 2 knots all at the same rpm. I do not usually run at higher rpm however the engine is rated for continuous output at 3000 rpm and a maximum output at 3600 rpm so there is some reserve available. I have been very pleased with the performance of the propeller.
Regarding backing: the Autoprop has lots of bite in reverse however the geometry of the hull, the 15 degree downward slope of the propeller shaft, and the shaft offset to starboard combine to create a substantial prop wash effect due mainly to the wash from the propeller hitting the hull and pushing the boat sideways. This effect will vary from boat-to-boat depending on the geometry of the drive-train. With a sail drive the prop wash effect should be near nil and only the prop walk will be present. A boat with a flat or near flat bottom will be little affected by the prop wash.
Something unrelated to the propeller that can affect backing is the installation of a hydraulic autopilot servo. If it limits rudder angle on the wrong side it may make it impossible to compensate for the prop walk/prop wash effects.
George Weeks (#155, Blue Run )
c. I hauled out in June and besides doing the bottom, polishing the hull, and installing a boarding ladder, I fitted a used autoprop. It has a diameter of 18 inches with 14 inches of pitch at max rpms. You will not believe the figures we obtained after launching the boat. Bearing in mind that I have a Yanmar 3 GM 30 F, at 2800 RPM (max is 3400) we achieved a straight line, flat calm speed of 8.2 knots (incredible). On easing back to 2200 RPM she was still doing 6 knots. The previous maximum speed on the fixed 15in X 14in pitch was 6 knots at 3400 RPM. Now for the best part…….backing out of the haulout slip I managed to reverse all the way out of the marina into the channel. Almost all the prop walk has gone. Leaving the dock is now a breeze. The only downside to this is I really miss the ability to throw the boat into the dock when reversing to a stop coming alongside (joke). I guess I am going to have to get used to a boat that goes, stops, and reverses in a straight line???!!
Jeremy Parrett (#101, Two Pelicans (ex #101, Pelican 1 / Two Pelicans) )
d. I tried the new ” J Prop “, has a real good bite and I had to reduce pitch considerably for the 33 HP of ours. As is now, the new prop is at 20 * 11, In forward I can get close to full RPM but in reverse the prop bites too much. I wonder if it’s the water flow difference under the boat ??? We played quite a bit with this new prop, and end result seems to be that with our engine, (Vetus 33 HP ) there is NO acceptable compromise with respect to pitch. Eg. if you choose a good forward performance, you end up with a SUB standard reverse, or vice versa. Seems that there is a different gearbox reduction in forward ( 3:1 ) to reverse ( ?? ). ( Our box. Hurth HBW 150 V ) My conclusion to date: Other than the feathering feature under sail, it was not worth the effort or expense, certainly not with our type of engine setup. It is worth to mention that the prop when set up for either direction bites VERY WELL, but not in both, as is our case. Considering the price of J Prop, and I really like their concept, why would they not allow for different pitch adjustment for Forward & Reverse ???? I will ask the factory in Italy that.
Regards, Frank Bryant, (s/v #186, Visitant)
e. We have just had #050, Opportunity away from the dock for the first time since installing the Autoprop, autopropinstalledshowingboatclearances.jpg . It was a quick motoring trial in rather lumpy conditions but seemed to perform well although it felt quite different from the fixed blade prop. We are off for a few days and will have a chance to get some real experience with the prop.
David Salter (s/v #050, Opportunity)
f. Our new 18 ” AutoProp must be helping with our improved sailing speed (previously a 17″ fixed 3 blade prop, autoprop.jpg ) A couple of days ago we achieved 7.2 knots by GPS with a beam reach, winds to 18 knots and somewhat rolly conditions (about 2 ft seas) with full main and one reef in our 135% genoa. We have generally found that reefing the genoa first (it’s easy!) moves our centre of effort forward and eases the rudder angle. Also the new (2nd season) fully battened, loose footed mainsail (from Quantum Sails) is easier to get flat and reduce heeling, hence reduce excessive rudder.
David Salter (#050, Opportunity)
g. You may recall that I fitted an Autoprop 3 blade folding propeller a couple of seasons ago. I have been pleased with the performance and now the maker, Bruntons, have come out with a newsletter. Here is the latest, http://www.bruntons-propellers.com/News/pdf_news_files/2007Newsletter.pdf .
David Salter (s/v #050, Opportunity)
Recently I have my hooks into a Yanmar 4JH4-HTE turbo diesel. This Yanmar has 2000 hours on it, new alternator, engine mounts, etc and a rebuilt KM4A transmission. The price is $5700 complete. Question: Has anyone installed a 4 cylinder Yanmar as a repower ? If so I would like to hear all about the issues a project such as this can produce. Best wishes, Jeremy and Jane Parrett (#101, Two Pelicans).
a. Some loose thoughts re: your repower …….. Having repowered ( former #186, Visitant ) to a new 50 HP Beta BV2203, the big issue with me was the mounting. Specifically: Compatibility with existing engine bed, incl. the final alignment of the shaft with the boat’s Stuffing Box.
In my case, since I did not want to do this at the boat, I had the time to duplicate the existing engine bed in my shop and only minor re location of the Beta engine mounts were needed to meet up with the old engine bed. Obviously you need to research the Yanmar foot print prior to …….. or have the Yanmar engine on hand. By having the duplicate engine bed off site, allowed me to align everything incl. the final height ( angle ) of the drive shaft / engine before-hand and all that was done on site was re drilling the engine mount in the boat’s bed. In my case, there was a 3/8″ thick s/s flat bar moulded into ( inside ) each length of engine bed stringer. You can re drill and re tap it, or some people just lag bolt the engine mounts.
Regardless how you proceed, I would strongly suggest installing a ” squeeze ” bulb on the fuel supply line. This will allow you to prime the fuel filters etc. by hand until you hear the fuel returning to tank. Doing this I have NEVER had to air bleed the system, esp. after filter change.
You may also want to service your Stuffing Box, ie. new or double clamps, shaft seal, packing ( put 1 xtra ring of it ) incl. tightness as this will NOT be accessible after the engine is mounted.
Hope that helps, good luck Jeremy & don’t hesitate to write if you need more. Frank Bryant (#186, Visitant).
b. Before taking my Corbin down through the South Pacific I replaced my old Volvo engine with this same Yanmar. The engine ran beautifully for the whole 4 years but there were problems with the installation. The transmission is a 2 to 1 ratio. My existing V drive is also with a 2 to 1 ratio. One had to be changed. New V drives would not fit into my boat without major changes so a ZF hydraulic transmission was added to the Yanmar. The transmission failed several times until I got it properly overhauled in Australia. (Another problem with a hydraulic type transmission is that it does not stop the free wheeling of the prop under sail.) My Yanmar now has over 2500 hours and runs very smoothly and dependably. It is a very common type of engine in the South Pacific so parts and help is available. The price sounds great, I ended up with a total bill for $25,000 for one installed new. Good luck, and great sailing. Nick Fenger, (#038, Dragon Star).
c. We just repowered with a Yanmar 4jh5e, not the turbo but the naturally aspirated version. Am ecstatic about the result, now doing 8 knots at 3,000rpm if needed, cruising / motorsailing at 6 knots with 1500 rpm. In my case the transmission was too long and had to be replaced with a shorter one so that the front of the engine could be raised so that the shaft would meet the transmission flange. Engine bed was redone twice at my expense although the installer screwed it up. Make sure your prop matches the engine too. Write if you have questions. Gerry S. (#087, Octopus I).
d. Yes, I have recently repowered from a Westerbeke 38B to the bigger Yanmar. Also with the km4a tranny with zero angle. We had to modify the bed rails slightly and raise the doghouse about 3 inches. The exhaust had to be upgraded to 3″ and a new prop fit to handle the horses. What a difference in overall close handling and backing! If you do go ahead with it make sure you are prepared for a major upgrade and not just a motor swap… Fair Winds Keith B. (#025, Agape).
e. The specs state that the Yanmar 4JH4 HTE is a 110 HP Turbo. For what it’s worth, Beta is Kubota based, a simple & uncomplicated ” Cast Iron ” engine that is widely used in mining equipment etc. or where the eqpt. runs 24/7 for days on end. I was not involved in the calculations regarding the HP / Transmission or the Prop Size / pitch etc. for a given boat, It is done by people much smarter than I. Suffice it to say that the Gearbox ( if it comes with engine from the factory ) is always sized to accommodate the HP of the engine, the important variable being gear ratio. That is important with regard to the output shaft speed for a given type of prop. That’s why it’s worth looking at adjustable pitch prop, as no matter what one calculates, it will NOT be the right thing and would need to be field adjustable. Cheers, Frank Bryant (#186, Visitant).
I’m trying to find out from the group if anyone has had to replace the prop strut and how they managed to get a new one. I hauled my Corbin this week and the yard found that my strut is broken. Any help you can provide would be greatly appreciated. Andy Jeschke, #052, Tilikum
a. Andy, my strut was custom cast in bronze from a pattern that I made. It is offset to port so that the propshaft would clear the skeg. (See strut pic) It was made by Atkins & Hoyle, the hatch people, in Toronto. I don’t think it could break – the hull would break first! Regards, David Salter (s/v #050, Opportunity)
b. Andy, my strut was one of the last produced, and was constructed of 1/2″ stainless steel and a section of stainless tubing. Use the pieces of your old one and find a good metal shop. Good luck, Hope this helps. John Milburn on #190, Katie (a PH-CC).
c. Andy, don’t fret my friend I have good news….In the past, I tried Buck Algonquin, General Propeller- and other companies throughout the internet. No luck… General Prop said they could fabricate one out of SS for $1200-1500 but it would take 3 weeks-backlogged. I called Mar-Tec Engineering and they said they could have one made in California out of bronze in about 2 weeks for $800. I shipped the pieces of my old strut with 2 day delivery. They had the strut back to me in no time and held to their price.They have a website… Cheers, Kent Dudley (s/v Jack Iron) Hull #086.
d. Andy, The strut on #186, Visitant is NOT cast but fabricated in pieces from 1/2″ S.S. and welded to suit the angles etc. ie. hull flange, tube etc. I would further respectfully suggest that if a new tube is fabricated that it be made shorter than the standard strut bearing or get a bearing that is substantially longer, Reason: future bearing removal. ( Just my 2 cts. worth Canadian ). Frank Bryant, (s/v #186, Visitant).
e. Andy, depending on the condition of the existing strut and the extent of the break you may be able to bring it to a stainless steel welder and have it welded and reinforced…assuming it’s stainless steel (it should be). If you need a new one, I would take the old one as a pattern to someone who can fabricate stainless steel parts. Have him use a good grade like 316 Stainless for the part. Most good machinists should be able to do this for you. I think the chance of finding a factory replacement part is slim to none. Jack Verheyden (#127, Kathrian).
f. Thank you for your help with the prop strut. I got a response from John on Katie but he suggested repair which I don’t think is possible with the condition of my strut. The yard manager thinks he can come up with something from off the shelf or their fab shop can probably make one. I’ll send an email with the final resolution. Thanks again , …Andy
Do I need to cut the cockpit floor to remove a saildrive? Lester H. (#010, Insouciance)
a. I removed my saildrive two times by pulling it backwards, by hand, from behind the engine. It is awkward but doable. The unit weighs only 60 pounds. It is a two man job; one inside the boat to pull and one outside to push and helping to angle the drive so it passes thru the hole in the bottom of the boat. I do not understand why you want to cut out the floor in the cockpit. Good luck, Valois Nadeau (#096, Giva).
b. In 2004, while in Australia, I replaced the original 35hp Volvo engine and 110S saildrive for a 50hp and 120S saildrive from the companionway. The engine was a tight fit but the saildrive was easy and carried inside by hand. I see no need to cut the cockpit floor. Good luck, Michel Z, “ex” Corbin owner (#108, Neige d’Ete).
c. Sorry for your troubles. Try not to get into it if you can help it. I have no photos or drawings. #186, Visitant had 3 removable panels. 2 large ones (full width of cockpit floor, from companionway to pedestal) and 1 small aft of the pedestal. The base floor openings of the cockpit floor were molded with a ” turned up & raised ” 1″ lip (similar to the forward deck lockers) with the covers overlapping. This gave water a way to drain into the channels without overflowing and without the need for excessive gasketing. These hatches had 8 x 1/4 – 20 round head (carriage) bolts with rubber washers and through bolted to below. Sorry Lester, of all the photos that I have, I never took any of the cockpit floor ……….. Regards, Frank Bryant (#186, Visitant).
d. I have a centre-cockpit that has a swing up floor section. There is a water drain lip in the floor around it. John Gleadle (#181, Spinnaker).
e. Our Corbin CC came with a large opening hatch on a recessed cockpit floor to act as a gutter system for the cockpit drains. This looks like it was moulded in the construction of the cockpit frame when the boat was built at Corbin ( I have no drawing or plans). I will be going to the boat next week and can send you some pics. Not sure how you would do a solid floor but I would suggest you re-enforce the opening and cutout of the cockpit floor and get a good gasket to seal the opening from green water. Will the saildrive not come out through the companion way door? Regards, Paul W. (#190, RKalliste’).
f. There should be some stainless steel sheet metal screws holding the removable cockpit floor panel in place. These are accessed from underneath. Once the screws are removed, just pry up on the panel. I found some bedding compound in between the two floor panels when I removed the upper panel. The lower floor is a molded flat surface inboard from the cockpit drain channels. Lay out the opening cut-out lines at least 2″ inboard of the inside edge of the drain channels. You will need this flat area to mount the upper floor panel seals. At the corners, mark the centers for a 3″ hole saw to give you a nice 1-1/2″ corner radius. You do not want square corners here in order to eliminate any stress concentration. Drill out the four corners with the 3″ hole saw, then cut away the floor with a sabre saw, or sawall. Make sure you have help, the panel is very heavy and must be well supported as you complete the final cut. It is cored with the mahogany plywood. The upper panel was cored with end grain balsa. I elected not to hinge my panel as it could only open towards the companionway due to the taper of the cockpit (newer deck design). 4 cams hold it in place against the hollow Buna D seals installed inboard of the drain channels. Very dry, no leaks. I’ll be working on my boat today and will take some pictures to send to you this evening. Best Regards, Jeff Shutic (#145, Luff Shack)
g. I have a saildrive on Bodacious. I had the gear box replaced a few years ago. The saildrive is attached to the gear box right behind the engine. There is no cockpit floorboard; the saildrive was removed via the companionway after removing 4 or 5 bolts. Regards, Murray F. (#102, Bodacious).
h. My 1982 aft cockpit model (built after Marius’ fire) has a partially removable sole, about 3 ft. fore/aft, bolted in which would expose the engine space. All the best, Bill Ullmann (#136, Saguaro).
i. We have a hatch in the cockpit floor that hinges up in order to access the engine room. I want to warn you that the hatch might impact the structural soundness of the cockpit floor. We felt it necessary to reinforce the floor under the steering pedestal. (We won’t be going to the boat for another month so I can’t send you pictures right now.) Just something to keep in mind. Nancy L. (#187, Toboggan).
Hi, We are currently sailing in the shallow (less than thirty feet) milky green waters of Phang Nga Bay. While the Bay is not terribly big, it has many shear-sided mountains that rise vertically out of the water. These limestone mountains are small in their diameter as compared to their height. Most of the islands in the bay are uninhabited, offering secluded anchorages under soaring cliffs fringed with jungle. Many of the islands have caves in which we take Therapy into to explore. Most of the caves open up to a small lake with shear sided walls, which are opened to the blue sky. Sometimes the cave is long giving one an aerie feeling as one paddles your way using a flashlight whose beacon is eaten up quickly by the cool blackness. Watch your head as the stalactites may reach down from the ceiling and touch you. Do not worry about the moaning of the water as your wake laps the limestone walls, and the quite talking you here is only the bats that you are disturbing along your way. #018, 2 Extreme is going to spend the year sailing between Thailand and north Malaysia. During the year, we will haul the boat, at that time I would like to change her propeller. Currently we are using a three-bladed fixed propeller that is powered by a Perkins 4-108 and a Hurth gearbox. I would like to know what the proper pitch, diameter, and number of blades for the most economical operations should be. I would appreciate the information, if someone in the club could help me out. Thank You, Henry and Mattie, (S/V #018, 2 Extreme), in Thailand waters.
a. Unfortunately I do not know the exact size of the propeller you need. To find the right prop, you also need the reduction of your gearbox. You should start with you present propeller, and determine the most important factor: the engine MUST be able to turn at its maximum RPM or no less than 100 RPM than the maximum RPM as seen in the engine manual. This would be the most efficient propeller and you should expect it to change as the engine wears and tears. If the propeller is too small you are spending more fuel for a given distance and if it is too big, you will burn your engine. The end result is obtained by trial and errors. Usually, I” of pitch will give or remove 200 RPM and 1″ of diameter will add or remove 400 RPM. This is not an exact science. Change the pitch when possible before changing the diameter. If you try to rev up and the engine does not reach its maximum RPM and black smoke comes out at the exhaust, calculate the number of RPM missing, divide by 200 and have your prop’s pitch adjusted by the number of inches you obtained. Hope this will help and have a wonderful day. Marius Corbin
b. A very important piece of information is needed. What is the reduction in your Hurth Gear? It varies widely, and is quite often different in forward and reverse. The propeller people want to know: 1. Gear reduction in forward, 2. Shaft horse power, and 3. Weight of the boat. I think much can be learned from the propeller you have. Since you want to change it, I’m assuming you’re having a problem, and want to change the pitch and / or diameter. You said you want to achieve the most economical operation. I interpret that as meaning you want to reduce engine RPMs and still travel at the same speed. With a fixed propeller, it’s tricky, and could well involve trial and error. Too much propeller (Pitch & diameter) will raise exhaust temperatures and result in engine problems. You can also experience engine lugging (No power) from a stand-still. They make all kinds of fancy (and expensive) non-fixed propellers to deal with these problems. Any decent prop shop can re-pitch your propeller, but be careful. If you are already at the best possible match between your propeller and the rest of your drive train, you could run into trouble. Perhaps knowing what I did will help you. My Corbin has a Pathfinder (gotta love that) rated at 42 horse power. Behind the engine is a Hurth Gear with 2.7 to 1 in forward and 1.5 to 1 in reverse. My propeller was a fixed 3 blade, 18 inch diameter / 12 inch pitch. This was not a good match — I needed more prop. I went for a 19 inch 3 blade Max-Prop (nice piece of change) because I also wanted a feathering propeller. In those days you had to haul the boat and take the prop apart to change the pitch. Today, all the feathering props allow external pitch adjustment — in the water. Max-Prop identifies blade pitch in degrees rather than inches. You get a conversion chart to get started. Through trial and error over several years I arrived at what I feel is a very good match for my boat. My prop is now set at 24 degrees of pitch, which converts to 15.8 inches. Don’t be lured into thinking that a 19 inch fixed propeller with 15.8 inches of pitch would, therefore, be appropriate. It would not. Max-Prop blades are flat. What they lack in shape, they make up for with pitch. I would be over-propped with a fixed prop of those dimensions. If you’re inclined to buy a new propeller, there’s a number of feathering propellers available today with a variety of features, and most are for substantially less money than the MaxProp. Feathering propellers allow you to sail faster and motor more efficiently. It worked for me. Hope I’ve helped. Best from Bob Cox — o the Corbin “#070, Dorisea”
c. A fixed prop is usually designed for a very narrow operating range and will not meet the requirements for all types of motoring conditions. A suggestion would be to go for a variable pitch prop such as the Brunton Auto Prop which automatically adjusts itself for any conditions encountered. Other variable pitch props require manual adjustments to get the “right” pitch and then it becomes a fixed feathering prop. We have used the Brunton Prop since its introduction in the UK in 1987 and have found it to be exactly as advertised. The Corbin now can be manoeuvred in REVERSE and has very little prop walk when docking in tight spots (our prop shaft is in-line with the hull). When motoring, one just sets the most comfortable engine rpm’s and the prop will adjust itself for the best pitch and speed with savings in fuel economy. The stopping power is phenomenal, but I have not tried the demonstration that Brunton factory showed of docking a 36ft sailboat at 6 knots with the boat stopping within its waterline length just before it reached its dock. The Corbin does stop very quickly but I don’t trust my flexible engine coupler to withstand the pull in reverse at full throttle. When sailing just leave the engine in gear, otherwise the prop will spin in reverse. The blades will feather to the flow of the water over the prop blades unlike other feathering props that feather to the prop shaft angle. The only maintenance I have had to do was to adjust the free play in the blades (each blade is independent of each other) this can be done in or out of the water. There is nothing to dismantle, to pack, or to repack. Lubricant and a general inspection will suffice. To obtain the correct size of prop you must specify your engine/gearbox combination and preferably have a dimensional drawing of your shaft/strut arrangement. I took a photograph of my strut with a scale rule attached to the shaft and enlarged the picture. My original fixed prop size was 18 ins diameter; the Brunton prop is 17ins Dia and my engine is a VW diesel (not a Pathfinder) coupled to a Hurth HBW 150 gearbox. Practical Sailor gave this prop top marks in their tests. Janis Priedkalns “#023, Simmerdim”.
d. Dear Henry & Mattie, Just for you I went outside on this sunny day at -13-degrees C to check on prop size. The hard paint on my prop conceals any engraved numbers but the diameter is 17″. I am pretty sure pitch is 12″. My engine is a Pathfinder 50 with 40 HP max. I think I could manage a larger pitch as the engine easily reaches max revs and in calm water we get about 7.5 knots. Don’t forget that prop tip clearance from the hull should be at least 15% of prop diameter, say 2.5″ minimum. It is worth checking the shaft taper as it is possible to have different tapers. SAE taper is 0.7500 in +/- 0.002 per foot (1/16″ per inch). For U.K. specifications taper may be 1″ per foot. Specify keyway also. Regards, David Salter, #050, Opportunity. We have just had #050, Opportunity away from the dock for the first time since installing the Autoprop. It was a quick motoring trial in rather lumpy conditions but seemed to perform well although it felt quite different from the fixed blade prop. We are off for a few days and will have a chance to get some real experience with the prop. David Salter (#050, Opportunity)
e. Dear Henry and Mattie. I would suggest an AUTOPROP for maximum thrust and economy. Other benefits include the ability to back up in straight lines as this type of propeller almost eliminates propwalk. Phone them at 1 800 801 8922 e mail email@example.com www.autoprop.com will get you all the info you need. The propeller you buy will be tailor made to your exact configuration by them. This propeller also almost completely eliminates drag. I would suggest a V strut unless one is already fitted. Take care, keep the news coming, Jeremy Parrett ..(s/v Pelican1) I have just installed an Autoprop.It has virtually eliminated propwalk, and I can actually drive the boat astern in complete control. Amazing!! On trials we achieved a speed of 8 knots at 2600 rpm at 2200 rpm we can maintain 7 knots….amazing!! It has put a big strain on the drive train though, and I will be rebuilding the Vetus coupling and installing a new bearing in the thrust block…both are complaining! Altogether though this add on has made an amazing difference to the boat. I cant wait to see the fuel economy figures. Jeremy Parrett (s/v #101, Pelican 1 / Two Pelicans)
Do you own a Pathfinder diesel? I would be interested to hear from anyone else with a Pathfinder engine. I have made a couple of modifications for accessories and have some questions re belts. Regards to all, David Salter (s/v #050, Opportunity)
a. David, I’ve just purchased a refurbished pathfinder engine from Pathfinder Marine in Montreal. These people are amazing! If you want ANY information on changing things on your engine call John at 1-514-695-6676. He’ll answer any questions and supply original parts. They’re still in business, and going strong. With the engine comes an original Pathfinder engine handbook (250 pages!) with all part #’s and repair instructions. They are also offering a deal on new engines and will take your old one on trade. Call John, he’s really knowledgeable and helpful. Paul Melanson (s/v #058, #058, Quintana Grande)
b. Hello, for Pathfinder information or upgrades, or parts… write to John at Pathfinder They are also known as Trigon Machinery Inc. out of the Montreal area. I have just bought a rebuilt pathfinder from their exchange program. They’ll upgrade you to a higher hp engine and take your old one on trade.(* Pathfinder trade-ins only) They’re extremely helpful and knowledgeable, and keep extensive files. Paul Melanson (s/v #058, #058, Quintana Grande)
I own #127, Kathrian, hull #127 Corbin 39 Special Edition. I am thinking of upgrading my propeller and wondered if any of our other Corbin owners had any advice for me. I have a VW 16D engine (from Pathfinder out of California in the late 70’s). It has a 52bhp rating at 4800 rmp rating. It’s hooked up with a Hurth V drive transmission which has a reduction ratio of 2.13 in forward and 2.22 in reverse. Currently I have a 3 blade fixed prop with these markings on it 17D 13 ( I’m assuming 17″ diameter, 13″ pitch). I’m thinking of changing to a feathering prop such as a MAX prop, or one of the other manufacturers. How does one determine the right size of prop, let alone the pitch, for their boat? I only want to do this once. Oh yes, I did see questions & also Marius Corbin’s answer about how to determine pitch. It didn’t talk about diameter though. What I was hoping to find out was what Corbin owners with similar engines were running. Also what the max diameter of propeller people are putting on as well. I’m sure some of our owners have upgraded to feathering props and I’m wondering what parameters they used to determine diameter and pitch. Jack Verheyden (#127, Kathrian).
a. Hi Jack, here’s my $ .02 ( CDN ) you may find it of some value. We originally had a 18*13 3 blade fixed prop @ 33 HP 3600 RPM engine and 3:1 gearbox , that set up was not quite right. I looked around for a variable pitch prop and settled on the 20″ dia. J Prop from bomon marine www.bomon.com and re pitched down. Since then, we re powered to a 50 HP @ 2600 RPM Beta Engine, same gearbox as yours and re pitched up. I like this prop as it can be CW or CCW rotation and can be re pitched easily ( even in the water ) and the blades have the same profile in forward or reverse and the hub is relatively small compared to others that I have seen. I have had it 4 yrs now and I love this product. As the pitch is not an exact science, there is a table that comes with the prop that gives the initial set up ( pitch ) but I’m sure one will have to adjust 1 or 2 clicks up / down from that initial setting. Of note: Bear in mind the idle speed of your engine ( ours is high @ 850 RPM ) as when you adjust for optimum motoring, you may find that your creep speed @ idle may not be what you want ( ours is a bit high ) Regards, Frank Bryant, s/v #186, Visitant (186)
b. Hi Jack My Corbin has a very similar power plant to yours. but my numbers are quite different. I have the Pathfinder, marine rated at 42 HP @ 4000 RPM. (Volks Wagon rates it at 50 HP @ 5000 RPM) My Hurth Gear (HBW 10) has a 2.7 to 1 reduction in forward and 1.5 to 1 in reverse. I had an 18 inch — fixed 3 blade prop, with a 12 inch pitch. I replaced it with a 19 inch, 3 blade Max Prop. The different reductions of the Hurth Gear (2.7 and 1.5) played a big part in the final solution, and I would like to share with you what I learned. First of all, it was my understanding that Hurth designed the ratios of the gear box to turn the wheel faster in reverse than in forward to off-set the inefficiencies of a fixed prop. The ratios that you offered for your transmission suggest that your wheel turns slower in reverse than in forward. I’m thinking that your numbers are probably wrong. If your transmission is installed in the boat, you can check the ratios as follows. Mark the prop shaft and turn the engine over by hand, counting the crankshaft revolutions required to complete 1 shaft revolution. Perform this test in both forward and reverse. This will yield the actual reductions. Feathering propellers: — The feathering propeller is great. It enabled me to convert more of my horsepower to thrust, increasing my motoring speed and efficiency, it stopped my shaft from turning while sailing, and increased my sailing speed and efficiency.
But it didn’t go off without a hitch. My old style Max prop does not have external pitch adjustments — it does not have provisions for obtaining different pitches in forward and reverse — it can not be removed or installed like a regular fixed prop. (For all intents and purposes, the boat must be hauled and the prop built on the shaft) There are feathering props on the market today that address and solve all these problems. For my application it was a bit of trial and error. Here’s why the different reductions in forward and reverse are important. The feathering propeller has the same efficiency in reverse that it has in forward. Therefore, the logic of Hearth increasing propeller speed in reverse does not apply. I found that the best pitch for my Max Prop was 24 degrees. (That’s degrees, not inches of pitch. For some reason the world may never know, Max Prop decided to depart from the standard) 24 degrees converts to 15.8 inches of pitch. Try to imagine my surprise the first time I threw the old girl in reverse. With almost twice the propeller RPMs as in forward, the engine was overwhelmed and bogged right down. I had no power in reverse. This was totally unacceptable, and I had to haul the boat again. I sent the prop to PYI and they modified the prop so that it had 6 degrees less pitch in reverse than it had in forward. This solved the problem and my prop was now optimized with 15.8 inches of pitch in forward and 11.5 inches of pitch in reverse. These numbers should help you establish a starting point once you are certain what your reduction ratios are. The greater the reduction is, the greater your pitch will need to be. Conversely, less reduction will require less pitch. The good thing about today’s feathering propellers is that they feature external pitch adjustment. Instead of hauling the boat, you just take a little dip into the refreshing waters of Canada. Hope I’ve helped. Best from Bob Cox (s/v Dorisea) (Hull 70)
c. We used to install 18″ 3 bladed Max Props, but 17″ is OK too. For the pitch, he should start setting it to the equivalent of 13″ and try it. He should be very close. Remember to allow the engine to turn its maximum RPM or 100 RPM less. Marius Corbin.
d. Hi there Jack, Nice to hear that you are coming along. We met last year when you kindly showed us your “baby”. We have repowered Necessity’s Westerbeke 33hp @ 3000 RPM with a Westerbeke 44Bfour (also 3000 RPM) last year. We retained the 3:1 ratio V-drive transmission. The 18″RH 16″Pitch 3 blade prop NecessityStrut.JPG was going to be too small for the new engine so we decided to bite the bullet and upgrade to a 20″ 3 blade feathering prop. (our old prop is for sale if you are interested.) After looking at the Max Prop & J Prop we decided on the Variprop because of it’s robust hub and the damping action as it switches from forward to reverse. Also, we can set a different pitch in forward and reverse and adjust them easily. I had a Max prop on an earlier boat and found that there was often quire a clunk on switching gears. The variprop seems quite easy on the shaft. We had a slight problem installing it as there was a very slight ridge on our shaft which prevented the new prop from gong on until it was removed. We found that a 20″ prop was all we could fit in the opening and it seems to work fine. With our low gear ratio our prop turns slower than yours will for a given RPM and you could likely get away with a smaller one. Adjustable pitch allows some latitude in fine tuning. We relied on Jesco Afheldt at Nautilus Propeller in Toronto jesco and nautilusvariprop.ca/ for sizing and initial setting. I think it is a type of black art. Engine manufacturers sometimes will offer a recommendation but in any event, if the prop is too large or too small you risk running afoul of the warranty. Here’s another site with a fair bit of info westbynorth.com/ Hope this helps. Let me know if you have more questions. Brian Hall (#135, Necessity).
e. Hi Jack, I am Lou Lieto, owner of #193, “Impresa” a PH Corbin 39. We are from the upstate NY area and sailed for many years in Lake Ontario. We loved Kingston; it’s a great small city! We currently sail in the Chesapeake and along the Atlantic coast. Impresa has a Yanmar 50 HP engine configured thru a Hurth V drive. As I recall the ratios are the same as the ones you quoted so it is likely the same model transmission. The engine & shaft are canted slightly to starboard to allow the shaft to be removed past the strut when needed. We have a MaxProp installed and have been very pleased with its performance. The boat moves in the lightest of air so, although I don’t have a fixed prop to compare it with, it seems that the feathering is performing as expected. The folks at Max Prop plus the yard that installed the engine selected the proper sizes. My prop is the model that may have the pitch adjusted, without disassembly, by a ring on the rear of the shaft. Some set screws need to be removed first. When the prop was first installed, I found that the engine would not get above about 2600 rpm. It is rated at a maximum of 3900 rpm. The experts I consulted advised me that the pitch was incorrect so I reset it and that cured the problem. My Yanmar runs smoothly and powering is no problem even in some rough conditions. Unfortunately, I cannot give you the prop dimensions right now. The information is on the boat which is about 360 miles from my home. I am planning to make a visit to the boat in the next few weeks so if that time frame meets your needs, I will let you know then. I can provide Max Prop model number, diameter, and final pitch setting. Is there anything else you would like? I could make you a copy of the owner’s manual if you like. Incidentally, the owner & designer of the Max Prop is usually at the US Boat show in Annapolis in October and I have found him to be very anxious to help his customers. I am sure that he would also respond to an email. I do not remember his name but the web site should be able to get you there. Unfortunately for us, the shaft angle and the natural prop walk caused by the prop rotation cause the boat to swing significantly to starboard in reverse until there is significant way built up. This makes backing into a slip very interesting – either done slowly with much pushing off and other comedies or done at 3 knots in reverse with attendant trepidation. I wonder if you have a similar problem and what you have done to manage it. What direction does your prop rotate? Good luck, Lou & Marilyn Lieto, #193 “Impresa” [add : Jack, The prop diameter is 17″ and it is set at a blade angle of 18 degrees which turns out to be just right for my engine to reach its maximum RPM of 3900. Cheers, Lou ]
f. We repowered #144, “Cormorant” our Corbin 39 Special Edition with a Yanmar 4JH2E (50hp) and then added a 3 blade Max prop. Our surveyor and Fred Hutchinson at PYI (Max prop guru) both calculated the diameter and pitch which worked out to 18 inch diameter and 12.5 inch pitch. If you are planning on installing a Max prop, be sure to speak directly to Fred Hutchinson at PYI and DO NOT trust anyone else, as someone or some people at PYI don’t have a clue. We have found the diameter and pitch to serve us very well in eight years and around 28 thousand NM –Annapolis to New Zealand and many side trips later. Do yourself a favor and COUNT the shaft revolutions from the engine to the prop to make double sure that your ratios are correct, as any error here will affect the pitch calculations. The prop maximum radius (not diameter) should be no greater than 90 per cent of the clearance between the center line of the prop shaft and the hull. In other words, prop tip clearance to hull should be ten percent of the distance between the shaft center line and the hull to avoid “pounding” and the prop tips pass the hull. Hope this helps. Our Corbin had a two blade fixed prop when we bought her, and was an absolute bear to handle in reverse. With the Max prop (and a bit of practice) we can now pretty much put her where we want her. It has made that much of a difference. More free advice: If and when you get your Max prop, take it out of the box a day or two before you intend to install it. Read the instruction book at least twice (maybe three times if you are slow learner like me!) and practice setting the pitch and assembling the prop at least twice or more. This will pay off big time when installation time comes. Two more points: You will need a good metal cutting blade in your hacksaw to cut off the end of your prop shaft to clear the end cap on the Max prop. The instruction book mentions this, but only in a sentence or so, and it’s easily overlooked. Second and last point: Think about spending a few more bucks and get the externally adjustable Max prop, because if you get the pitch wrong the first time, the haulout fee will exceed the cost of the external adjustment. And if you get the pitch wrong the second time….you get the picture? Happy Sailing. Harry and Jane Hungate (#144, Cormorant), Whangarei, New Zealand.
I am having trouble bleeding air from the fuel system after change of filters. I only have a small pamphlet on the Perkins 4-108. It only references two places on the mechanical pump. One is oblivious the other isn’t. Do you have any information that would assist me?. THANKS Dave (s/v #145, Saw-Whet)
a. Hi Dave, Having had a Yanmar, Vetus and now a Beta ( Kubota ) engines, so I don’t see why it would not work on a Perkins.. I installed a hand primer pump ( a squeeze bulb ) type, BEFORE the first fuel filter in the system. After a filter change, I just hand prime the fuel lines until I hear the fuel returning to the tank, and THAT IS IT. Works like a charm and eliminates the ” bowl filling ” thing and the clean up. This scheme will do nothing if you have air after the fuel pump or in the Hi press. lines to injectors. I hope this helps Regards, Frank Bryant, s/v #186, Visitant
b. The Perkins is easily bled with the starboard side manual fuel pump. If necessary, unscrew the coupling on the right. G & B Stuurop, (s/v Octopus I) www.stuurop.ch, Menorca, Spain
c. On any fuel system that you are having trouble bleeding, you should check the fuel pickup tube in the fuel tank. Years ago it was common practice to put a screen on the end of the pickup tube. This screen is subject to plugging and should be removed, as it is more hazard than help. Second, check the gaskets on you fuel filters. If you have a Racor primary fuel filter, the O-ring in the T-handle that hold down the lid can leak air if not properly installed. Finally, make sure that the diaphragm in your lift pump (the fuel pump on the engine) is not leaking, as it could allow air into the fuel, and worse, diesel into your engine oil. Hope this helps, regards [Opua, New Zealand] , Harry Hungate, (s/v Cormorant)
d. Hi, I don’t own a Perkins so I don’t have direct experience…….but I did see this discussion. It would lead me to look for a plug where a return line could be connected. See the link.http://www.voy.com/119861/510.html It sounds like ““Rainsail”” successfully bled his injector system by removing the plug filling an inlet for an unused return line. Pete Bowes
e. Good day Dave Shaw, My wife and I purchased our Corbin 39′ in June 1989 and moved aboard in May 1990. S/V MALLARD was fitted with a Perkins 4-108 and we inherited two good maintenance manuals and a parts description manual. Regrettably the engine had been poorly maintained by the two previous owners; we spent $3,000USD on repairs in Salem, Mass in September 1990; the engine gave out completely as we neared Daytona Beach, Florida in November 1990. It proved to be cheaper to purchase a new Perkins 4-108 than to have the old one (with only 1,900 hrs) repaired. By the time we sold the boat in Kingston, ON in July of this year, the engine was still going strong after almost 7,000 hours; it started at first try on launching, after 10 months on the hard. The new owners have reached Long Island Sound by now, after going down the St Lawrence and down the coast of the Maritime Provinces; they have had no problems with the engine whatsoever. Long preamble to say that, from December 1990 until July 2004, we lived aboard on average 50 weeks out of every year and gained a great deal of “hands-on” experience with our Perkins 4-108. We changed the fuel injector pump and tips on several occasions, as well as the starter motor, etc. The mechanic who installed our Perkins in December 1990 showed us an efficient, effective and easy way to bleed the engine; you will not find these steps described in any manual; you normally have to be a member of the “mechanics fraternity” to be clued-in on these procedures. The operation requires 2 individuals.
STEP 1: Armed with a commercial type blue absorbent paper towel, you crack open, with a 5/16″ wrench, the small screw on the side of the LUCAS fuel injector pump. One person activates by hand the small lever pump in the fuel line; the other ensures that all the air has been purged out of the fuel injector pump and waits until a clear jet of diesel, completely free of air bubbles emerges from the pump. Stop pumping and tighten the screw. By this time, the fuel injector pump is full of diesel yet the fuel has not travelled up the copper tubing to the 4 Injector Tips/Atomizers.
STEP 2: Crack open all 4 nuts (5/8″ wrench) holding the copper fuel lines to the Injector Tips/Atomizers; the mechanic did it by loosening only 2 of the 4 but this procedure never worked well for us. One person works the starter while the one with the wrench watches closely for fuel leaking out where the copper tubing joins the atomizers; as soon as fuel starts flowing, usually at cylinder 1 first, finger OFF the starter button and tighten nut in question. Same procedure for the 3 other cylinders; it takes less starter time with each subsequent atomizer; the engine often starts running by the time the 3rd nut has been tightened. The small manual that comes with the engine leads one to believe that, once all the air has been purged from the Injector pump, you are ready to start the engine. This was never the case for us since, as mentioned earlier, you cannot achieve enough fuel pressure with the small hand lever pump to get the diesel all the way up to the atomizers.
Hope the above will prove to be of some assistance. Guy Comeau, ex-owner of S/V #075, MALLARD, now sailing south under new name of s/v #075, NOVA STAR.
I have the Westerbeke 33 with a V drive and I need to repack the packing gland under the engine. It drips more than it should after running. What is the secret to getting to it? There must be a trick since it is in very difficult location. David Williams (#154, Sunshine)
a. David, Pull your v-drive back. It may seem like a hassle but it does not take long; you will have a chance to never seize your trans bolts and a better understanding of your v-drive and how once freed from engine you will then do it again with little effort. You will spend less time and effort trying to get at those packing nuts with much more satisfaction. Cappy deMontigny (#169, “CAPBAM”)
b. David, We have a similar v-drive. We replaced the packing gland with a PSS shaft seal and have had no problems with it. They don’t need periodic repacking. It was put on by the yard at the time our engine was removed for replacement. Not sure whether it could actually be installed with the engine in place. Hope this is a bit of help. Brian Hall, (#135, Necessity), Grand Bend, Ontario, Canada
c. I had similar problem. I have a Westerbeke 40hp, V drive, shaft 1.25`. To open the stuffing box locking ring I used a tool that is used in the plumbing trade.. Its adjustable jaws will fit most nuts. But for me the lesson in humility was to learn that it was a LEFT HAND THREAD….. Cheers. Dale (#162, Tranquilium)
d. David, I am the owner of #159, Corail IV Hull # 159. Indeed it is very difficult to access this important gadget. I assume your engine is located under the cockpit like mine which is the Yanmar 50. Also assume your V drive is located under the stairs leading down to the pilothouse from the cockpit. In my case, I cannot see the packing gland and have to feel blindly my way with both arms on either side of the V drive which is cornered by the the battery banks. Once you have located, by feel, the locknut the best way to unfreeze it is to tap it with something like a hammer head until it moves a little bit. Then using a special homemade key you can move the locknut back and tighten the packing nut. In my case special keys sold in marine store are too long which is the reason I have a homemade one. Attached are the pictures of the tool used to adjust the packing: packing gland tool , packing gland tool dimensions . Please let me know if you need further assistance. Good luck and feel free to contact me for any questions. Claude Gagnon, Sechelt BC (#159, Corail IV).
e. This is a rather tardy response, nonetheless it was of interest to me since I have a W-33 and just changed my stuffing box. I replaced the original stuffing box with a much simpler unit that only requires 9/16” or 1/2″ wrenches to tighten up the stuffing box. The original unit was impossible to adjust when water flow increased. It is a Buck-Algonquin rectangular Flanged Packing Box. Check it out at www.buckalgonquin.com . Tim O’Neil (#138 Whaleback)
I would be interested to know what other boat owners have used when changing out the cutlass bearing on their propeller shaft? I am chiefly interested in knowing if their replacement had a brass sleeve or if it was non-metalic. Thanks for your help. David Hibbard (#195, Endorphin).
a. I have a bronze (or brass) sleeved cutlass bearing and it has not needed replacement. I bought a non-metallic bearing as a spare part when building the boat. This was made by Thordon and they still exist! http://www.thordonbearings.com/ The bearing is made slightly oversized and is fitted by freezing to shrink it and allow an interference fit according to the installation instructions I have. The following comes from http://www.henleyspropellers.com/thordon.htm :
XL Propeller Shaft Bearings – are available in a full range of shafts frrom 3/4″ to 40″. These bearings have their water grooves moulded in. They are designed as direct replacements for bronze/rubber Cutlass-type bearings. XL Propeller shaft bearings are available fully-finished, ready to install, and semi-finished for machining to suit specific shaft and housing dimensions. Semi-finished bearings are designed with a small amount of extra material on the inside and outside so that they can be machined to accommodate minor variations in shaft and housing dimensions. D. Salter, s/v #050, Opportunity.
b. I have brass …………. replaced in 2002 / 2003 still good as new in 2012. Get at least 1″ longer than you need, that will help to get it moving if you need to take it out again & grease it before re install. Oooops ! Grease the brass sleeve …… not the rubber insert ….lol. Frank Bryant ( #186, Visitant).
I do have a question. If anybody else has installed a Volvo diesel with a sail drive I would like to know the propeller size they went with. I have a 15×13 fixed 3 blade prop and I think I need a little less pitch. My engine doesn’t get up to its rated revs and overheats if run wide open. Maybe a 15×11 or 16×11 would do better? My engine is a Volvo Penta md17c – 110s 36 hp diesel. It’s 3 cylinder and pushes the boat at about 5.5 knots. I like the engine a lot but have always had this overheating problem. Mine is fresh water cooled (the first the company ever sold in the U.S.) and if the engine overheats the plastic impeller on the fresh water circulating pump becomes loose and spins on the shaft. The only solution I have found it to buy a new pump (now on number 3 at $320.00 each). Is yours fresh water cooled and do you have any of these problems? Thanks, Bill Schwartz, (s/v #090, Moonshadow)
a. I use a 2-bladed prop (16″ diameter x 11″ pitch LH rotation) on my Volvo MD 11c engine (23 HP) and am satisfied with its performance. Cooling water to the saildrive is NOT connected. The engine has NO fresh water cooling. Lester Helmus (s/v #010, Insouciance)
Can I repower my engine while retaining my saildrive? I have a 120S Volvo saildrive and a two cylinder 24 HP Volvo MD11C engine. Lester Helmus, s/v #010, Insouciance
a. Yes. Volvo saildrive owners now have the option of retaining their saildrive transmission when repowering with a new Beta Marine engine. For example, if your engine is a Volvo MD11 with saildrive, you may order the new Beta Marine 20hp or 28hp engine so it will fit your presently installed Volvo saildrive transmission and engine bed. This is ideal for the boat owner wishing to save money and time when repowering. Please contact Joe DeMers for details at http://affordablemarine.com/
If any member would have recommendations for a bow thruster I would appreciate it. Regards, Guy Viger (#189, Tangaroa V).
a. Regarding the bow thruster: I am satisfied, the power is OK and the consumption of electricity is reasonable. If I have to say something is wrong is the fact it has a double propeller which gives me a hard time to clean off barnacles, because you don’t have access inside to clean without taking out the propellers. If you have only one propeller, you can clean it with a snorkel. Excuse my english. Normand Bouchard (#140, Urantia)
b. I have bought the Volvo Penta model QL-06-CT600-12. It has a 132 lbs thrust and is a single prop with a tunnel size of 160mm, ( 6.29”). It is compact, internal dimensions are 12.44 ” X 5.91 ” . The cost is at bit less than 3000 $ + installation when all accessories are included. I could have chosen a more powerful model, but with the space available, that model seemed the most appropriate. Normand had already answered me after your request for info. I guess he forgot to copy you. Regards, Guy Viger (#189, Tangaroa V).
I have been reading about the Autoprop propeller brand on this site and elsewhere. My Hull # 154 has Westerbeke 33 with Hurth 150 transmission. Currently have 18″ fixed prop which seems adequate under limited conditions; however reversing is tricky to say the least. Anyone else have experience with these props? I read Jeremy’s and David’s accounts, but these were quite a time back. Perhaps they and others might update their views. Autoprop has proposed a 19.5 inch (h5-506mm) for this application. Best regards”, Tim Baggett (#154, Sunshine)
a. Although I don’t have an Autoprop I do have a 3-blade Variprofile propellor. It is 21″ with approx. 13″ pitch and drives our boat quite well. It has a feathering propellor so that in reverse it reverses the blades and gives the boat equal thrust in reverse as in forward. This has greatly improved our boat handling in tight places and reversing is also improved somewhat. I don’t think you will ever get a Corbin to reverse all that well due to the fairly long keel. It will never back into a dock like a Beneteau with a fin keel. I think a reversing prop is the best you can achieve and the rest ….. well you just learn to live with it. Jack Verheyden (#127, Kathrian).
b. My Autoprop is working fine after 6 years. Jeremy Parrett (#101, Two Pelicans).
c. Responding to an email from Lester re: your Autoprop. Don’t know anyone that has one. I assume that Autoprop has the same profile Forward / Reverse e.g. my 20″ J Prop does. The only issue being the pitch. I don’t know if the Autoprop’s pitch is field adjustable. Again my J Prop pitch is and it took a few tries to get it right. Cheers, Frank Bryant ( #186, Visitant).
d. I only understand the prop diameter from your message and don’t see the pitch. This sounds too large for a 33 HP engine. I have a 40 HP Pathfinder and my prop is smaller than the one you refer to, at 18″ dia and 12″ pitch. It is also an H5 with 3 blades. Regards, David Salter (#050, Opportunity).
e. This response might be a bit late to be of much use to you but here is my experience with Autoprop… Our hull #155, “Blue Run” has a Westerbeke W58 with a Hurth V-drive transmission (15 degree down angle). Engine under the companionway steps. I installed an 18″ Autoprop in 2006. Under flat water no wind conditions we get 6.5 knots at about 1800 rpm. At 2100 rpm (the engines torque peak) we will make 7+. With wind we lose about a knot and with waves in the 3 to 4 foot range about 2 knots all at the same rpm. I do not usually run at higher rpm however the engine is rated for continuous output at 3000 rpm and a maximum output at 3600 rpm so there is some reserve available. I have been very pleased with the performance of the propeller. Regarding backing: the Autoprop has lots of bite in reverse however the geometry of the hull, the 15 degree downward slope of the propeller shaft, and the shaft offset to starboard combine to create a substantial prop wash effect due mainly to the wash from the propeller hitting the hull and pushing the boat sideways. This effect will vary from boat-to-boat depending on the geometry of the drive-train. With a sail drive the prop wash effect should be near nil and only the prop walk will be present. A boat with a flat or near flat bottom will be little affected by the prop wash.
Something unrelated to the propeller that can affect backing is the installation of a hydraulic autopilot servo. If it limits rudder angle on the wrong side it may make it impossible to compensate for the prop walk/prop wash effects. George Weeks (#155, Blue Run).