>it occurred to me that I have not herd of anyone EVER wearing out an engine in a pleasure craft.. Diesels maybe not. But I have had friends with boats with gas engines-- outboard, inboard, and inboard/outboard-- who have had the engines in their boats basically wear out. Granted the engines were pretty old when they finally lost enough compression to qualify as being "worn out." But these were in boats that were used quite a lot, fishing mostly. I suppose you have to define what "wear out" means. To me, it's not things like pumps failing or injectors getting worn. Wearing out to me means ring and cylinder wear is to the point where compression is being lost, camshaft lobes have been worn down to the point where valve performance is being affected, rocker shafts are worn down on their undersides to the point where the ability to set the correct valve clearances are affected, valve guide tolerances are way out of spec, and so on. In the limited experience I've had with rebuilding automotive engines, these things all seem to happen together. If the cylinder walls are worn enough to hook a fingernail on the lip where the top ring on the piston changes direction, the other stuff-- worn cam and rocker arm surfaces, worn valve guides, tired crank and cam bearings, etc.-- all seem to be at the point where they need dealing with, too. It's not so much that the engine doesn't run, but it doesn't run the way it's supposed to and there are no more adjustments or exterior component fixes that can make it run better. It's just "worn out." Given the relative rarity that the diesel are run in boats like ours-- the average use of a recreational trawler's engines has got to be ten to twenty hours a year based on the majority of boats I see just in our marina that rarely, if ever, go anywhere-- the real danger to the life of the diesels in a trawler is lack of use, not overuse. Hoses harden and crack, seals dry out, lubricated parts gum up, deposits in old lube oil attacks the crank and bearings, and so on to the point where when the engine is run. there are a lot of potential component failures, some of which could permanently damage the engine. Which prompts a question perhaps some of you with way more experience in this kind of boating than me can answer. If we assume a well-built, intelligently marinized marine diesel has such a potentially long life, why is it that so many ads for used trawlers call out the fact that the boat has been repowered recently, or that the engines have recently been overhauled? For example, I see a number of ads for Grand Banks boats from the '70s and '80s that say "new John Deeres" or "new Cummins power," or "new Lugger installed in 2000." In the case of the boats from the '70s and early '80s, it's a pretty safe bet they were originally powered with Ford Lehmans. These are certainly not hot-rod engines and they won't force a Grand Banks hull through the water as fast as it can be forced to go, but they're pretty good engines, albeit low tech and quite unsophisticated. I've been told by people who know about engines that a properly maintained and operated Ford Lehman should be good for 12,000 - 14,000 hours before needing major work, and there are examples of the breed out there that have accumulated as many as 25,000 hours without major work. So why so many repowerings? Is it because a lot of people don't maintain their engines and so problems occur with exterior components like pumps and heat exchangers and they fry the engines? Is it because people with lots of money-- given the cost of new marine diesels and their installation-- simply want something newer than the rude and crude lumps the boats were powered with originally? I can see new shafts, new propellers, overhauled transmissions, new raw water and cooling pumps, new alternators, new fuel tanks, and that sort of thing. But if the core diesels we all have are so tough and long-lived (which I believe they are) why do so many people seem to change them out after ten or fifteen or twenty years? I've always operated machinery with the philosophy that the whole point is to NOT have to spend money on fixing or replacing anything. So I'm delighted to have a boat with engines that in theory should be good for more years than I will live. ______________________________ C. Marin Faure GB36-403 "La Perouse" Bellingham, Washington

<<...the average use of a recreational trawler's engines has got to be ten to twenty hours a year based on the majority of boats I see just in our marina that rarely, if ever, go anywhere-- the real danger to the life of the diesels in a trawler is lack of use, not overuse. Hoses harden and crack, seals dry out, lubricated parts gum up, deposits in old lube oil attacks the crank and bearings, and so on to the point where when the engine is run. there are a lot of potential component failures, some of which could permanently damage the engine.>> Quite true. I hate to see an engine die of old age instead of wearing out. That's why I've run my John Deere 4900 hours in the last 6 years and 8 months. When shopping for a boat, don't worry about high engine hours (within reason) nearly as much as engine condition and maintenance. No maintenance logs? Probably irregular, if any, maintenance. John Deere NA diesels regularly go 35,000 hours in continuous generator service, 1800 rpm 24/7, so it's hard to wear them out. Most pleasure craft diesels seem to die, not wear out, after about 20 years from what I have seen. Corrosion, disuse, lack of maintenance and abuse eventually kill the engine. These engines could certainly be rebuilt, but it is often not economical to do so. Parts prices are sometimes astounding, and skilled mechanic labor far more expensive than factory labor trained to do only one small part of the job. Many rebuild quotes seem to hover around half the new engine price, but be careful. Most rebuilds exclude certain parts that have limited life, like electrical wiring, starters, alternators and other accessories. Mark Richter, Winnie the Pooh

Marin wrote: Which prompts a question: >> snip<<< why is it that so many ads for used trawlers call out the fact that the boat has been repowered recently, or that the engines have recently been overhauled? >>> snip<<<< So why so many repowerings? Is it because a lot of people don't maintain their engines and so problems occur with exterior components like pumps and heat exchangers and they fry the engines? REPLY I can only answer based on my personal observations. In all the cases I am familiar with, only one ( a commercial boat ) was due to actual engine failure. The crankshaft broke. A failure that Detroit said should not have happened and they suggested a metalurgical analysis of the sheared bolts to confirm that this was an unusual failure. Of the rest most were due to owner negligence in maintenance causing such problems as cracked cylinder blocks due to overheating under load or ice forming in the cooling jackets during winter layup. Running out of oil due to massive loss of oil which went unnoticed until too late or blown headgaskets which in turn caused hydrostatic lock and broken cranks. I do get the impression that a fair number of engine blocks were ruined from broken connecting rods etc. This in turn suggests over revving, or problems with lubrication. I do recall one nearly new engine that shattered due to excessive shaft vibration causd by severe misalignment. I also know of one person who was "conned" into thinking he needed a complete engine repowering job. Based on the botched up installations of the new Yanmar diesels I suspect the yard manager was only interested in a job with a higher profit margin than a simple repair of external components on what was likely a fairly good engine block. Yhis situation in turn begs the question of how many engine problems were mis-diagnosed as a worn engine instead of simply a repair and adjustment of ancilliary equipment. There seems to be a shortage of competent and knowledgeable mechanics who can really diagnose and trouble shoot engines instead of simply exchanging parts until the engine runs again. We have discussed this issue before. We live in a throw away consumer society and few people really know how to fix things. Could it be that some yards simply diagnose the problem as being a worn engine and because customers trust them, they accept the diagnosis as being valid and approve the engine repower job? cheers Arild --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.705 / Virus Database: 461 - Release Date: 6/12/2004