My CD27, circa 1980, has developed engine problems. Specifically the governor on the top of the engine is worn so that it is difficult to start. In talking with the mechanic in the boatyard he said that it is difficult to get parts for the YSM8 engine, that even if a new governor could be obtained or a part machined, it would be an expensive repair. An old engine like this Yanmar which is raw cooled probably has extensive internal corrosion. So the recommendation is to replace the Yanmar with a new engine. I have read through the old threads that discuss the problems and the expense, but don't see a way out if I am going to continue to sail Pagoo.
I seem to have several options: put in a Yanmar 2GM or 3GM, or a Beta Marine BZ482 or BD722. With a rated displacement of 7500 lbs and, probably, a loaded displacement of 9000 lbs, this would suggest an 18 hp engine. In talking with one dealer, he suggested that this is a waste of money - that the 13.5 or 14 hp engines would be perfectly adequate. The higher hp engines can also support a higher amperage alternator, possibly important if I were to put radar on the boat.
I would love to hear people's opinions on this
repowering a CD27
Moderator: Jim Walsh
-
Clay Stalker
- Posts: 390
- Joined: Feb 5th, '05, 12:07
- Location: 17' Town Class Sloop
Repowering CD27
IMHO...put in a Yanmar 2GMF...or they actually have a new model to replace this with a different name, but it is still an 18HP engine...they made some improvements like easier access to the water pump etc....still a great engine. I had a 2GM in my old CD27. a 13HP version, and it did have plenty of power...all you would need in most circumstances. They don't make this version now, only the smaller 10 and the 18. A 3GM would be a waste of money for this boat. As for the other makers, I cannot speak to them as I have no experience with them. However, I can speak highly of Yanmar from my past boat and my present one, which has a 2GMF 15HP in it...adequate, but I would prefer to have 18HP.....for my money, go for the new Yanmar 18HP 2 cylinder engine.
Clay Stalker
Clay Stalker
-
John Vigor
Power restriction
Bill, one thing to bear in mind is that your engine power must be transmitted through the propeller, and for various reasons the biggest propeller you can fit to a CD27 is one of 12 inches diameter.
The blades of a prop need a certain amount of surface area to absorb the engine power and if your engine is too powerful the prop will simply cavitate and destroy itself rather quickly without giving you any extra speed.
What is too much power for a 12-inch three-blade prop turning at some 1,500 rpm and trying to push a very heavy displacement 27-footer? Well, I think a Yanmar 3 GM producing 28 hp would certainly be over the top, and 18 to 20 hp might be approaching the upper limit but still feasible.
I have a Westerbeast twin-cylinder 13 hp on my CD27 and it gives me a little more than hull speed at 2,800 rpm and cruises nicely at just over 5 knots at 2,200 rpm. Hull speed is 5.9 knots and top sustainable speed in calm water with my engine is 6.1 knots.
Incidentally, I could never reach top engine revs before I recently had my prop repitched. The engine would start to lug at 1,800 rpm and 5.5 knots, after which the black smoke of unburned fuel would pour from the exhaust. I had the pitch reduced from 11 inches to 9 inches and it has made a wonderful difference. The prop shop charged $46, which I regard as a bargain.
The engine runs faster now, for the same speed through the water, but is quieter and cooler because it is no longer straining to turn an overpitched prop. For the first time, I've been able to extract full power from the engine at top revs, which I'm sure will come in useful some day in heavy weather, powering against wind and wave.
And, as a bonus, I find the stern walks far less to port in reverse than it used to, so I can back up straighter and more easily. Even in forward gear, I don't have to hold the tiller over so far to go straight ahead. I hadn't really fully realized before that the coarseness of the pitch would so greatly affect the propensity of the prop to walk sideways in the water, but it's only logical now that I think about it.
This is the second Cape Dory I've had on which the propeller pitch was too great. I think previous owners overpitched them because you can achieve good speeds in calm weather at relatively low engine revs, and, of course, get marvellous fuel mileage. But it's like pedalling slowly in top gear on a bike. It's hard on the motive power and hell when you get to a hill, or a headwind.
Anyway, my gut feeling is that 8 hp is too little for the CD27; 13 hp is pretty good for almost every circumstance; 15 hp will give you a quieter run for the same speed, and normally have plenty of power to spare; 18 to 20 hp is probably still usable with a 12-inch diameter prop, but perhaps a waste of power and money.
Don't forget, either, that the more powerful an engine, the heavier it is. The CD27 was designed for an 8 hp engine. My 13 hp Westerbeast was a factory afterthought and depresses the boat at the stern, which the smaller CDs are prone to anyhow. I had to add ballast way up forward to level her up, cure the tendency to squat, and make the cockpit drain properly. So check the engine weights before you make a decision on a new power plant.
John Vigor
CD27 "Sangoma"
Bellingham, WA
The blades of a prop need a certain amount of surface area to absorb the engine power and if your engine is too powerful the prop will simply cavitate and destroy itself rather quickly without giving you any extra speed.
What is too much power for a 12-inch three-blade prop turning at some 1,500 rpm and trying to push a very heavy displacement 27-footer? Well, I think a Yanmar 3 GM producing 28 hp would certainly be over the top, and 18 to 20 hp might be approaching the upper limit but still feasible.
I have a Westerbeast twin-cylinder 13 hp on my CD27 and it gives me a little more than hull speed at 2,800 rpm and cruises nicely at just over 5 knots at 2,200 rpm. Hull speed is 5.9 knots and top sustainable speed in calm water with my engine is 6.1 knots.
Incidentally, I could never reach top engine revs before I recently had my prop repitched. The engine would start to lug at 1,800 rpm and 5.5 knots, after which the black smoke of unburned fuel would pour from the exhaust. I had the pitch reduced from 11 inches to 9 inches and it has made a wonderful difference. The prop shop charged $46, which I regard as a bargain.
The engine runs faster now, for the same speed through the water, but is quieter and cooler because it is no longer straining to turn an overpitched prop. For the first time, I've been able to extract full power from the engine at top revs, which I'm sure will come in useful some day in heavy weather, powering against wind and wave.
And, as a bonus, I find the stern walks far less to port in reverse than it used to, so I can back up straighter and more easily. Even in forward gear, I don't have to hold the tiller over so far to go straight ahead. I hadn't really fully realized before that the coarseness of the pitch would so greatly affect the propensity of the prop to walk sideways in the water, but it's only logical now that I think about it.
This is the second Cape Dory I've had on which the propeller pitch was too great. I think previous owners overpitched them because you can achieve good speeds in calm weather at relatively low engine revs, and, of course, get marvellous fuel mileage. But it's like pedalling slowly in top gear on a bike. It's hard on the motive power and hell when you get to a hill, or a headwind.
Anyway, my gut feeling is that 8 hp is too little for the CD27; 13 hp is pretty good for almost every circumstance; 15 hp will give you a quieter run for the same speed, and normally have plenty of power to spare; 18 to 20 hp is probably still usable with a 12-inch diameter prop, but perhaps a waste of power and money.
Don't forget, either, that the more powerful an engine, the heavier it is. The CD27 was designed for an 8 hp engine. My 13 hp Westerbeast was a factory afterthought and depresses the boat at the stern, which the smaller CDs are prone to anyhow. I had to add ballast way up forward to level her up, cure the tendency to squat, and make the cockpit drain properly. So check the engine weights before you make a decision on a new power plant.
John Vigor
CD27 "Sangoma"
Bellingham, WA
-
Andy Denmark
- Posts: 630
- Joined: Feb 5th, '05, 11:38
What John said +
Hi Bill,
John sums it up pretty well. My CD-27, Rhiannon, has the Westerbeke 13 which, in my opinion, is the perfect match for the boat. Due to the size limitations of the aperture and prop, be it 2 or 3 blade, there is no way you can couple 18 h.p. to the water. IMHO, 18 h.p. is a waste of power and boat units. I find 13 h.p. to be just about perfect provided you take the time to tweak the prop and keep the heavy stuff out of the stern so it doesn't screw up the trim.
The Westerbeke 13 is a fine powerplant but it is 21 years old and technology has improved a lot since it was built. Given a free choice of engines, I would choose the Betamarine twin, built on a Kubota block. I have seen this installation in several boats. It is compact and neat. Also, the way Beta's measure their horsepower makes it an even a better bargain for the $$$.
Sounds like you have hit the point with the 8 h.p. Yanmar where the cost of repairs and the nuisance factors could easily exceed the value of keeping the old engine. I have just overseen the exchange of a 1984 Universal to a brand new M-23 and the difference is astounding. The service points are accessible from the front of the engine whereas those on the old engine were nearly impossible to reach. That alone is worth a lot. Most of the newer engines are more ergonomically designed in this way (it's about time!)
Hope this helps,
________
HERBAL VAPORIZER
John sums it up pretty well. My CD-27, Rhiannon, has the Westerbeke 13 which, in my opinion, is the perfect match for the boat. Due to the size limitations of the aperture and prop, be it 2 or 3 blade, there is no way you can couple 18 h.p. to the water. IMHO, 18 h.p. is a waste of power and boat units. I find 13 h.p. to be just about perfect provided you take the time to tweak the prop and keep the heavy stuff out of the stern so it doesn't screw up the trim.
The Westerbeke 13 is a fine powerplant but it is 21 years old and technology has improved a lot since it was built. Given a free choice of engines, I would choose the Betamarine twin, built on a Kubota block. I have seen this installation in several boats. It is compact and neat. Also, the way Beta's measure their horsepower makes it an even a better bargain for the $$$.
Sounds like you have hit the point with the 8 h.p. Yanmar where the cost of repairs and the nuisance factors could easily exceed the value of keeping the old engine. I have just overseen the exchange of a 1984 Universal to a brand new M-23 and the difference is astounding. The service points are accessible from the front of the engine whereas those on the old engine were nearly impossible to reach. That alone is worth a lot. Most of the newer engines are more ergonomically designed in this way (it's about time!)
Hope this helps,
________
HERBAL VAPORIZER
Last edited by Andy Denmark on Feb 13th, '11, 03:18, edited 1 time in total.
-
Kurt
- Posts: 188
- Joined: Feb 8th, '05, 11:12
- Location: 27' Cape Dory (Alerion),
9' Dyer,
Grosse Pointe, Michigan
I installed a Beta Marine BZ482 last year in my CD27 and absolutely love it. I chose the Beta only after carefully comparing physical dimensions of the engine choices available. I compared Westerbeke (Mitsubishi), Vetus (Mitsubishi), Yanmar, Universal (Kubota), Volvo, Beta (Kubota) and Nanni (Kubota). I chose the Beta BECAUSE IT FIT the existing CD27 engine beds with the least amount of modification. I had to raise the beds 2.5" by laminating white oak to each stringer. The new engine was then lowered onto the now raised stringers. There were 3 areas that presented a problem for me. (1) getting YSM-8 out required removal of the cylinder head and other parts in order to get it through the opening behind the companion way steps. (2) getting the Beta in required removal of the exhaust heat exchanger, heat exchanger studs, alternator, oil filter etc. (3) the exhaust was a bugger to engineer. The high rise exhaust supplied by Beta won't fit the CD27's hull because of the upturn of the bilge just behind the engine. I ended up using the stock aluminum (READ: longlasting) water injection elbow along with a Centek horizontal inlet water lift muffler. This combination has worked out very nicely. I was able to use original engine controls although with new cables. John Vigor's comments are very accuate. My 12"x8" prop had too little pitch. I then tried an 11" pitch and it was too much. 10" pitch allows the engine to reach 3600 WOT rpm although I normally run at 2400 while making about 5.5 knots. At 3600 the stern digs in, the bow rises and I approach 7 knots!
The Kubota diesel is extemely smooth and quiet for a diesel. Because it's smaller in displacment than the 2GM, the pistons and rotating mass are lower which results in less vibration. I would go as far to say that the 482cc displacment Kubota industrial engine actually vibrtates less than a 3 cylinder Yanmar 3GM based on my personal experience. It's smoothness has amazed me. I'm very happy with the engine. 13.5hp is plenty of power for the CD27. I now have about 60 hours on the engine and have had zero problems with it. It always starts on the first compression stroke. I was able to sell my old YSM-8 for $1000. Write to me if you'd like more information or photos of my installation
The Kubota diesel is extemely smooth and quiet for a diesel. Because it's smaller in displacment than the 2GM, the pistons and rotating mass are lower which results in less vibration. I would go as far to say that the 482cc displacment Kubota industrial engine actually vibrtates less than a 3 cylinder Yanmar 3GM based on my personal experience. It's smoothness has amazed me. I'm very happy with the engine. 13.5hp is plenty of power for the CD27. I now have about 60 hours on the engine and have had zero problems with it. It always starts on the first compression stroke. I was able to sell my old YSM-8 for $1000. Write to me if you'd like more information or photos of my installation
-
Bill Chapple
- Posts: 23
- Joined: Feb 5th, '05, 10:15
- Location: CD 27 Pagoo
Many thanks to you all for your advice. It looks as though the Beta Marine BZ482 would be fine. Thank you John for the advice about the propeller pitch. I am really interested, Kurt, about the problem with the high rise exhaust. I will contact you about your installation; I would love to get photos. Did you find the 40 amp alternator adequate for your power needs?
-
Kurt
- Posts: 188
- Joined: Feb 8th, '05, 11:12
- Location: 27' Cape Dory (Alerion),
9' Dyer,
Grosse Pointe, Michigan
Bill,
My electrical needs are minimal. I occasionally sail at night with running lights and cabin lights on. I also own a 12 volt LCD TV with built in DVD player that my kids use. But I don't have electrical refrigeration and I don't stay at anchor for days at a time as other sailors sometimes do. I have to run the engine for at least 30 minutes (15 out, 15 back in) every time I go sailing so the standard 37 amp alternator has been just fine for me. Write to me at kjlgpw@aol.com and I'll reply with some photos.
Kurt
My electrical needs are minimal. I occasionally sail at night with running lights and cabin lights on. I also own a 12 volt LCD TV with built in DVD player that my kids use. But I don't have electrical refrigeration and I don't stay at anchor for days at a time as other sailors sometimes do. I have to run the engine for at least 30 minutes (15 out, 15 back in) every time I go sailing so the standard 37 amp alternator has been just fine for me. Write to me at kjlgpw@aol.com and I'll reply with some photos.
Kurt
-
sloopjohnl
kubota engines
just some thoughts:
diesel engines do not like to lug so getting a higher horsepower engine and then running it constantly at lower rpms due to propeller limitations is not a good thing.
we have a number of kubota engines in our landscape equipment and most go 3000 to 4000 hours before the equipment is traded in. 100 hour oil changes and good maintenance easily provides those hours with absolutely no engine work including injectors. that's a lot of running time for our sailboats.
diesel engines do not like to lug so getting a higher horsepower engine and then running it constantly at lower rpms due to propeller limitations is not a good thing.
we have a number of kubota engines in our landscape equipment and most go 3000 to 4000 hours before the equipment is traded in. 100 hour oil changes and good maintenance easily provides those hours with absolutely no engine work including injectors. that's a lot of running time for our sailboats.
-
Jacko
Re: Repowering CD27
I replaced the YSM-8 in mine with a Yanmar 2GMF. Westerbeke, Beta, Universal, and the especially horrible Volvo 1, 2, and 3000 series, to name a few, are the products of assemblers using various and sundry components from different suppliers, starting with the engine. In addition to the engine, Yanmar manufactures, and is responsible for, the engine, injection pump, marine gear, heat exchanger, raw water pump, panel, and harness. Starter and alternator are built to their specification. This engine in my boat has shown incredible reliability for the past eighteen years, and is also some indication as to why Yanmar's penetration in the OEM sailboat market approaches eighty percent.Clay Stalker wrote:IMHO...put in a Yanmar 2GMF...or they actually have a new model to replace this with a different name, but it is still an 18HP engine...they made some improvements like easier access to the water pump etc....still a great engine. I had a 2GM in my old CD27. a 13HP version, and it did have plenty of power...all you would need in most circumstances. They don't make this version now, only the smaller 10 and the 18. A 3GM would be a waste of money for this boat. As for the other makers, I cannot speak to them as I have no experience with them. However, I can speak highly of Yanmar from my past boat and my present one, which has a 2GMF 15HP in it...adequate, but I would prefer to have 18HP.....for my money, go for the new Yanmar 18HP 2 cylinder engine.
Clay Stalker
-
Clay Stalker
- Posts: 390
- Joined: Feb 5th, '05, 12:07
- Location: 17' Town Class Sloop
Yanmar Diesels
Well, Jacko, as you can see from above....not many agree with us on this....I can only speak from personal experience with two of these engines and I do all my own work on them....say what they will or want, but IMHO these are the best engines out there, bar none....
Clay Stalker
Clay Stalker
-
Ben Thomas
- Posts: 215
- Joined: Feb 5th, '05, 12:17
- Location: 82 CD30 Milagro Hull #248
Beta-Marine BZ482
Bill, If you are interested in the Beta, please drop me a line. I am the Beta dealer here in Oregon. I can possilbly save you some money. I can drop ship engines from the main distributor in N.C. I have sold a couple to other Cape Dory owners as well. Best Regards, Ben Thomas Oregon Marine Industries.