Removing Diesel Adding Outboard
Printed From: Laser 28 International Class Association
Category: Laser 28 General
Forum Name: Maintenance
Forum Description: All the things to care for your boat
URL: http://www.laser28.org/forum/forum_posts.asp?TID=382
Printed Date: 23 November 2024 at 7:28pm
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Topic: Removing Diesel Adding Outboard
Posted By: Guests
Subject: Removing Diesel Adding Outboard
Date Posted: 21 April 2010 at 9:25am
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Good morning all:
The 30-year-old 8 hp Buhk is being removed from Andiamo! - sacrilege I know. I am putting an outboard motor mount on the stern, and would like to know if anyone has done this before, and if they have any particular advice. My concern is that the stern is relatively light structurally, and if the constant flexing as a result of the outboard hanging out there will be an issue. Should I reinforce the stern? To mollify all those who would never think of such a thing, I will have the engine rebuilt and replaced, and the offending engine removed from the stern next year. When we do race we use PHRF, not class rules, so no issue there. As well, we are planning to ocean sail this summer in Passamaquoddy Bay (tidal range 7.5 m) and like the idea of more power... |
Replies:
Posted By: Bill Layton
Date Posted: 21 April 2010 at 10:05am
Yes we did this last year to a boat here in montreal. We put a 3/4" piece of plywood inside the transom (18" x 18") as a backup plate. and on the outside we put another 3/4" piece of plywood painted white (a little bigger in dimension than the motor mount flange) and then thru bolted the engine bracket thru it all and it worked very well while the old Bukh was getting rebuilt. FYI we used a 6hp 2 stroke Yamaha 2005 model regular shaft with the regular prop and it pushed the boat to hull speed easily. Hope this helps 
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Posted By: Bill Layton
Date Posted: 23 April 2010 at 10:22am
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I'll add my reply here as well just for all to see:
I think you will be fine if you use large backup brackets on both sides (particularly on the inside) One note of interest, is when we did this here in Montreal, the fellow left his saildrive in place and he still won races with the outboard on the transom. It doesn't appear to affect the performance of the boat any and its the easiest/fastest/ least expensive solution to keeping your boat powered. I'm currently rebuilding 2 Bukh engines now. Parts are indeed getting harder to get. I really like the motor setup on the new Farr 25. http://www.youtube.com/watch?v=stQiqek24ro&feature=youtu.be&a An alternative method for engine replacement, the downside is the glass work involved. Cheers Bill |
Posted By: lsr28
Date Posted: 23 April 2010 at 11:06am
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when I fully restored my engine last year, I had the chance to have the "help" of Erik Jørgensen of LSM-Diesel [info@lsm-diesel.dk] parts were priced good (Danish Crown vs Can$ helps I think). Shipping form DK was also very fast (took about 6 days to Canada). No shortage of parts there...
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Posted By: Guests
Date Posted: 23 April 2010 at 11:11am
| The Farr 25 idea is awesome. Do you know if the bracket is a custom item? I would be willing to try the idea. |
Posted By: Bill Layton
Date Posted: 23 April 2010 at 12:25pm
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I get my parts thru the Canadian Distributor Keith Strutt in Kingston Ontario 613-634-8100, He has most parts in stock and pricing is same as you will get from Denmark.
There isn't any more info on that Farr 25 than can be found on google, but eventually I suspect their method and equipment will become available thru someone |
Posted By: bal149
Date Posted: 05 October 2010 at 9:55pm
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with all due respect and after having owned a few boats with outboards- the plywood panel should be epoxied to the transom. These new 4 stroke motors generate a lot of torque and can twist that hanger right around. If you are planning to put a small 2 stroke on the boat it will work but only if there is a slight breeze and no waves. To power a laser 28 you need a motor with an extra long foot and the last time I looked these were 8 hp and up.- try holding on to the motor and you will get an idea of the twisting force that can be generated. If the diesel can be repaired why bother?
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Posted By: bal149
Date Posted: 05 October 2010 at 10:30pm
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if I didn't turn you off with my posting about outboards-the main advantage of which, when they stop working ,one can just unbolt them and let them sink to the bottom- i have a Nissan 9.8 four stroke,4 blade prop electric starter and 25 inch foot with 60 hrs of use- I'll even throw in an adjustable hanger- but I don't recommend it unless you are absolutely convinced that this is the way to go. Boulet lemelin can make you a sail drive from an outboard and Johansen will sell you a Honda powered sail drive- $5000.00 or so
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Posted By: Guests
Date Posted: 06 October 2010 at 10:22am
| Do you have a link for Johansen? |
Posted By: frfletch
Date Posted: 08 October 2010 at 12:51am
| Why go away from the Bukh? This is a great little engine. I just rebuilt mine and converted it to fresh-water cooling with a heat exchanger. I have used outboards before, but if you are using it for any more than getting to and from the race starting line, the diesel is far better. |
Posted By: bal149
Date Posted: 08 October 2010 at 1:28am
| my mistake for the name-wwwsaildrive280.com |
Posted By: Bill Layton
Date Posted: 08 October 2010 at 10:20am
| saildrive280.com doesn't exist anymore. It hasn't for a while now. If you read post #2 in this thread you'll see that a 6hp 2-stroke worked very well. It not only got the L28 to hull speed it did it in a good sea as well. And this was with a regular shaft and prop. Needless to say with a long shaft and the available high pitched sailboat prop it would perform even better. This outboard weighed 60 Lbs, whereas the 4 stroke version of the same weighed a little over 100 Lbs. Which I'm assuming is why the Farr25 comes with a 2-stroke only, maybe for compartment size reasons as well. But as frfletch mentions above the range with a diesel is incomparable to any gas power engine |
Posted By: tprice
Date Posted: 08 October 2010 at 10:34am
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Bill,
When I had my Laser 28 on the Chesapeake, we were lucky to have a Bukh dealer and repair service in Galesville (30 min from Annap.). Waterway, I think, was the name of the company. High prices but intelligent and knowledgable work and plenty of advice for free! I wonder if he still supplies parts and service? I would certainly recommend Waterway. TP |
Posted By: frfletch
Date Posted: 08 October 2010 at 1:17pm
| I'm not sure about the states, but parts can still be obtained via Crinmar Marine in Kingston, Ontario (Keith Strutt), and the UK agent. Both of these people are knowledgeable. I don't know what is wrong with your Bukh, but unless you dropped it from a 10 storey building the type of parts that it is likely to need should mostly be able to be fixed. Replacement bits such as rings are actually manufactured in Italy by another company and those rings clearly fit other engines as well, so they will continue to be available. Bearings, likely unnecessary, are mostly generic as well as are the seals. The head (and head gasket)that houses the valves, etc, is a critical piece and if it becomes to badly corroded such that it cannot be repaired, then that item is truly a Bukh part and will not be found elsewhere. Looking at the head of my engine is what drove me to converting it to freshwater cooling via a heat exchanger. That is not a very difficult conversion and I'm happy to help anyone interested in pursuing that path. |
Posted By: frfletch
Date Posted: 08 October 2010 at 1:28pm
| To the owner of Andiamo, if you have not yet removed your Bukh engine, I have tripped upon some very helpful techniques in doing this, though they rely on your boat having opening windows in the cockpit leading to the quarter birth and sail locker. I learned from Bill that these windows were optional and that not all Lasers have them, but if yours does, you can take the pain out of engine removal and replacement. I'm happy to outline the techniques and sequence of this if you wish. |
Posted By: Guests
Date Posted: 08 October 2010 at 3:06pm
| To bring you up-to-date on Andiamo, the Bukh was removed this spring and the block and head are corroded from the 25+ years in seawater. I sold the engine and saildrive to a fellow clubmember for spares. There is a discussion on the removal of the engine, which I read AFTER removal. I was able to manhandle the engine out of the boat using block and tackle. I epoxied a backing plate of 3/4" plywood to the stern on the inside and mounted a heavy duty mount for the 9.8 longshaft Nissan 4-stroke. This engine has remote controls for starting and shifting. I mounted the remote in the starboard lazarette. The prop was changed to a low speed prop, yet I get 25% more speed, especially in headwinds. Now there is no oil in the bilge, more storage and no drag. We race PHRF so no issues. So far - so good! |
Posted By: bal149
Date Posted: 08 October 2010 at 8:29pm
| curious-how did you convert the engine to an isolated cooling system? |
Posted By: frfletch
Date Posted: 08 October 2010 at 9:46pm
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From 4" stock T-6 aluminum, I turned a pulley for an A-section best that fits to the top of the flywheel via the flywheel hold-down nut. On the port side of the engine, if you look closely, you will see several female threaded bosses that take an 8mm bolts or threaded studs. These were used to bold in place a piece of 3/16" x 3" angle aluminum, trimmed to fit such that the top L comes directly under the alloy plate portion of the crankcase just below the flywheel. To this I bolted another 3" x 3" angle to provide vertical surface to which I bolted the second pump. I used an Obedorfer centrifigul with pedestal base for this. From the 4" stock, I turned another pulley to fit onto the pump and trimmed it down to 3 1/2" diameter. This was not to gain more pump rpm, but to give more clearance to the sliding hatch door on the port side quarterbirth. An A-section 27" belt connects the two pulleys that I mounted high enough above the flywheel so that one could still use the rope pull start on the flywheel if necessary. To allow clearance for the knot of the pull-rope, the belt clears the top of the flywheel by about 5/8" or 30mm. I have photos of this arrangement that I would be happy to send if you provide me with your email address.
San Juan Engineering made the heat exchanger with integral expansion tank. It is 9" long, and about 3" in diameter. It fits to the front of the engine directly behind the access stairs. On the front of the engine there are 4 studs (either 6 or 8mm) that fix the steel mounting bracket to the engine. I replaced these studs with longer studs so that the studs could be used to also hold two pieces of 1/4" x 2" pieces of aluminum situated vertically on which to mount the tank, where the radiator cap must become the highest point of the cooling system. I used the Bukh's own Johnson pump to circulate the raw water that now comes from the sea, to the heat exchanger, and then back to the regular cooling water outlet fitting at the exhaust elbow. The centrifugal pump circulates the coolant pulling it off the bottom of the heat exchanger, driving it to the engine up at the thermostat area just the way the raw water used to go, and then back into the top of the heat exchanger. That's it! If you supply me with an email address, I will send some pics which are a better explanation of it. |
Posted By: frfletch
Date Posted: 10 October 2010 at 6:37pm
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more testing. Sorry!
http://img261.imageshack.us/i/dsc0020g.jpg/ - [img=http://img261.imageshack.us/img261/1223/dsc0020g.th.jpg - |
Posted By: bal149
Date Posted: 10 October 2010 at 11:17pm
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thanks for the pictures-very nice work. A freshwater cooling system gets rid of one of the Bukh's 2 big problems-dissimilar metals being one and the lack of an oil filter the other. Your installation is well designed and nicely fabricated-the way you worked out belt tension quite simple and quite effective. I will definitely look into doing this-my boat is sailed in fresh water but raw water cooling is in my opinion a bad thing. The Bukh was designed as a lifeboat motor and in that case it might make sense to take shortcuts with the cooling but your installation is a much better approach. A new head is 4k-if available
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Posted By: frfletch
Date Posted: 11 October 2010 at 2:20pm
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Thank you Charles. Couple of things: I think that the belt tension device is not necessary in the end, especially if using a full A-section belt. Since the belt wraps all the way around the pulleys and does not go to a third idler pulley or anything, their is plenty of contact friction in those pulleys to drive the pump whose demand is 1/32 of a horsepower without much tention. Also, there is not much room between the pump pulley and the sliding hatch on the port side, so it is important to keep the entire pump assembly as close to the engine as possible. Anyway, that is a minor detail.
One advantage of the recirculating cooling system is that it will allow us to experiment with hotter running thermostats without the danger of accumulating salt and mineral build-up in the block and head. Raw water engine thermostats are set pretty cool to reduce that, and engines would prefer to be run hotter if they could. That's next on my journey with this thing. I hope heads for this engine have not gone to $4,000. I was able to salvage mine, but I think Keith Strutt from Crinmar indicated something in the $1800-$1900 range for a new head which is still not small. Regarding the lack of oil filter, there is a little internal oil filter on (or in) the Bukh that upon cleaning I did see picked up some small bits. However I have taken two of these engines apart and was amazed to see how clean everything was inside the crankcase. Because the oil drain does not really come from the very bottom of the crankcase, and the method of pumping oil out via the dip stick tube from the top, I expected to see some sludge and some amount of "babbit" (small metal particles) accumulated in the bottom cover of the crankcase, but it was perfectly clean. With relatively frequent oil changes, and periodically removing the little mesh oil filter and cleaning it, I did not get the idea that oil was a problem. At 25 years old, there was no measurable ridge either at the top or bottom of the cylinder wall. While I don't have a proper "inside" micrometer, I did use locking telescopic I.D. devices and then measured those with micrometer and would say that if there was measurable wear, it was in the .0005 range (1/2 of 1/1000th") which is nothing and indicates that things must have been pretty clean in there. |
Posted By: WarBird
Date Posted: 31 October 2010 at 7:29am
| Can the head gasket be replace while the motor is still in the boat. Rapscallion has a low C/R (very easy to crank ovr). We don't see water in the oil and all other indication are the otor is good, just no compression. |
Posted By: Guests
Date Posted: 02 November 2010 at 5:28pm
| I have successfully removed the head and replaced the gasket a couple of times (before I removed the entire engine and went for an outboard). Its fairly easy - although I tell people its sort of like performing brain surgery thru the rectum. Ensure that you note which is the intake and exhaust valve rod for replacement. In order to hold the rods in their proper place when reattaching the head, I used small pieces of stiff foam which I tied to a string so that I could pull them out when the head was in-place. It was either that or stand the boat on its nose. This is also a good time to check the valve lash if you want. |
Posted By: frfletch
Date Posted: 02 November 2010 at 6:04pm
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I had the same thing happen recently, but unfortunately I had more to do than replace a head gasket. What had happened was: The head gasket became compromised when rust particles from the head broke loose and plugged the cooling water exit at the point where it joins the exhaust elbow causing over heating. After the event,the engine ran, but a small amount of moisture got into the cylinder via the head gasket. This froze the piston rings down into the grooves in which they are situated, preventing their outward spring action to engage the cylinder walls.....hence, no compression, and engine would no longer function. This required more work leading to my pulling the engine, going through everything, and while doing so I honed the cylinder walls and installed new rings.
However, compression can also be compromised if the valves are not seating. This may require valve grinding, but first pull off the valve cover and check the clearance on the rocker arms to see if there is .20mm on the intake and .25mm on the exhaust side. If there is no clearance at all, then the valves will not come own and seat. I doubt this is your problem. Also check to torque on the injector hold-down bolts/nuts. Also, before starting anything, you should just check the tension on the head hold-down nuts which also hold the cylinder block in place. The workshop manual suggest these be checked periodically. When you go to remove the head in-situ, after the nuts are removed, do not go at the gap between the head and the cylinder block with a screw driver and hammer to pull them apart. You could try an aluminum wedge and hammer, but if none of that works, then: 1. Remove the injector nozzle. 2. Stick something down the hole to find the top of the piston and then rotate the flywheel until the piston is in the bottom position. 3. Fill the cylinder with gear oilvia the injector nozzle hole. 4. Replace the injector nozzle. 5. Loosen the hold-down bolts retaining the head a few turns. 6. Crank the engine over with the battery and key. This will pop the head off without you scaring the faces of the cylinder wall and the head on the first turn. 7. Clean up the spilt oil. To reduce mess, one may not have to fill the entire area with oil, but I have not tried it that way. The piston actually raises at the top just above the actual top of the cylinder, into the gap created by the head gasket, so there is not much volume when the piston is at the top. I should think that maybe only an inch of oil on top of the piston will do. Of course, if all the rings are siezed down, then this may not work, or will require more oil. I suggest using 90 weight gear oil for this to better your chances if any of the rings are compromised. If you don't have one, download a copy of the workshop manual for this engine before starting. It is much more comprehensive than the owner's manual. You can find it if you Google around a little. If you can't find it, contact me and I will send it to you in pdf. When the head has been pulled, you can also remove the cylinder block to see the condition of the rings. If they are all a mess, but no scoring or grooves are evident, you could just at that point remove the piston, clean the ring grooves, and replace the rings, however by this time a lot of work has been done and it may pay to remove the engine and go through it on the bench. I chose the latter as at 63, and with no discs remaining in any of my lumbar area and all lumbar vertebra degenerating, I have limited ability to work in those spaces for very long. If you elect to remove the engine, and if you have two windows in your cockpit (a Laser option, contact me for an easy procedure I've worked out to get the engine out without much effort or pain. Good luck. |
Posted By: Chris Ross
Date Posted: 15 September 2011 at 7:19am
| How much is a rebuilt Bukh DV8 going for? |
Posted By: WarBird
Date Posted: 04 October 2011 at 12:47pm
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Is the cylinder block seperate from the crankcase? Can I reassemble the pistonand rings into the liner with out removing the engine?
Thanks. |
Posted By: Bill Layton
Date Posted: 04 October 2011 at 1:16pm
| yes you can but its gets complicated in that you need to find a way to support the crankcase while removing/installing the cylinder.... as the engine frame support attaches to the cylinder. Some people at this stage just yank the complete engine and do all the gaskets |
Posted By: WarBird
Date Posted: 04 October 2011 at 2:23pm
| Thanks Bill |