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  Topic Review (Newest First)
03-19-2013 08:33 PM
Re: defining "rebuilt"

Rebuilt: How long is a piece of string? What does a hen weigh?

I'd want to see the work order and the guarantee that were done for the job, to see what was done and what the shop's reputation was. A good rebuild is a hand0built engine and that's actually better than an assembly-line engine, but finding someone who does it all to that degree won't be easy.

There are some parts (often head bolts or cylinder bolts) that are supposed to be used once and then replaced. Some folks will try to save a couple of bucks by re-using them. I know someone who insisted a shop re-use them because they were perfectly good...and he bought a second rebuild one year later, when one of them failed, as it was supposed to.

Rebuilt, used, new, they can all have issues.
03-19-2013 05:46 PM
Re: defining "rebuilt"

I tossed the "rebuild" idea around a long time before re-powering. The questions I asked were:

How long do I plan to keep the boat?
How old is the engine?
When was the engine designed and was it of sufficient power originally?

A buddy of mine had the Perkins on his 39 ft sailboat rebuilt by a very reputable marine mechanic. This was an out-of-the-boat rebuild that cost half of the quoted price of a complete replacement. Last summer, sailing off the north coast of British Columbia in quite remote waters, the starter motor gear drive shattered, a small conflict between the replacement starter and the old ring gear on the flywheel causing the starter to stay in gear. Who would have thought. There have been a few other problems as well, all addressed by the mechanic. However, at this stage the owner has lost a bit of faith in the old engine.

When I answered the questions it seemed prudent to invest a considerable amount of money in a replacement engine. There is no "monetary" investment in a 35 year old 30 ft production fiberglass sailboat that now has an engine worth half the value of the boat. However, there is an investment in peace of mind knowing that there is very little likelyhood of fatigue cracks developing in the foreseeable future. All the parts are as new as the engine. I now have a more powerful engine that runs quieter, uses less fuel and is easier to service than the original. Although I'm always prepared to face mechanical emergencies when out on the water, I would rather not plan my trips based on where I can get engine servicing if required. And yes, I have sailed point to point (and prefer to do so!), even sailing into my slip at the marina. But when I need to hit the starter button, I want to hear the sound of a running engine!

When it comes to looking at buying a boat with a "rebuilt" engine I want to see all the receipts! I used to rebuild car/truck engines as a hobby. I know want's involved. I understand why it's so expensive. Even when I did it for myself I kept all the receipts, for warranty issues if nothing else. Some paint, new hoses and belts can make an engine look very nice. But it's the same old engine.
03-17-2013 08:05 PM
Re: defining "rebuilt"

That "In frame" job you describe is what is commonly called a "freshening" in automotive circles. Top drag racing teams do it between EVERY race. That's every 4 seconds of run time. The block stays in the frame but that's it - some junior team member has to lie under it replacing the bearings.

Those guys are amazing to watch - they can strip and completely freshen a 10,000 horsepower engine in 20 minutes.
03-17-2013 05:38 PM
Capt. Gary Randall
Re: defining "rebuilt"

example: "Sir my alternator does not seem to be charging the batteries"
would you like me to test it for you?
well it appears that your alternator is not working!
would you like a rebuilt alternator or would you like a new one?

example: "Sir My engine doesn't seem to have oil pressure and knocking"
after a close inspection your engine will need some serious repair!
would you like me to perform a
" in frame overhaul in the Boat" understanding that I cannot give you a full warranty on these repairs due to the fact that the engine probably has metal circulated throughout all the oil passages which I don't recommend!
Or would you like me to remove the engine and overhaul it in my shop,and boiling out the block and cleaning all the savable parts including the cylinder head in a shop clean environment?
all moving parts replaced and put back to factory specifications? This also will include a one-year warranty!
The point I'm trying to make is the "inframe overhaul"and understandng, not only is not acceptable but also could cost you more because the amount of time it takes to work in a small space ( flat rate labor) on top of that you don't have a complete overhaul. Usually it's more efficient to overhaul the engine in a shop and the results you'll end up with is a totally overhauled better product. The "in frame overhaul" should only be performed, when you have (no other choice). But you also must understand you're going to end up with an inferior product.
CaptG ps: beware of 'rebuilt engines"
03-16-2013 08:56 PM
Re: defining "rebuilt"

I've found there are three kinds of rebuilt engines on boats.

Spray can rebuilds - new paint, maybe belts & hoses. Looks good but that's all.

Freshened engine - new rings & bearings in an un-machined block. valve job and any externals needed - injectors, pumps etc.

Rebuilt or major overhaul. This is what Porfin is currently detailing on his thread. In this case - a proper rebuild - only the major components are recycled, after re-machining them to be within factory new tolerances. All wear items - springs, rings, liners, pumps etc. etc. are replaced with new. High pressure pump and injectors are checked and replaced as required. The engine has to come off it's mounts for this although I've seen it done inside the boat, on the cabin sole when full removal to a shop would require deck surgery.

Only the last level of work qualifies as a "rebuilt" engine - the other two are tidied up or serviced and freshened respectively. Anything other description or representation is deceptive at best and fraud in most cases.
03-16-2013 08:39 PM
Re: defining "rebuilt"

Originally Posted by night0wl View Post
When rebuilding an diesel, is line honing done and bigger bearings done as they are in gasoline engines?
Line honing in and of itself does not change the bearings. The caps are faced to shrink the bore and then it is honed back to standard.

Turning the crank is what reduces journal diameters and requires oversize bearings.

Line honing is not standard practice, it falls into the "quality" or "blueprinting" categories. It is a very good idea.
03-16-2013 05:08 PM
Re: defining "rebuilt"

Originally Posted by Capt. Gary Randall View Post
.....There are two kinds of overhaul, the first one is a "in frame overhaul". This means that the unit was not removed from the vessel and repaired in place....
Great description. Just to clarify, this 'in frame overhaul' has serious limitations to removing the motor.
03-16-2013 04:56 PM
Capt. Gary Randall
Re: defining "rebuilt"

In the commercial marine industry the word "rebuilt" is not usually used when associated with a Marine engine or transmission itself. the Word rebuilt is usually used with accessories,starters, alternators, fuel injection , waterpumps, injectors etc. when discussing the main engine or transmission (alone)the term is usually called "overhaul".There are two kinds of overhaul, the first one is a "in frame overhaul". This means that the unit was not removed from the vessel and repaired in place. This takes place often because the job requires that parts be replaced quickly and only the parts needed will be replaced. Example: the engine had a failure on cylinder number four,therefore the Piston,sleeve, rings,connecting rod, rod bearings and wrist-pin were replaced. The other term "overhaul" means the engine or unit were removed from the vessel brought into any shop "clean environment" and "overhauled" meaning replacement of all moving parts including the crankshaft camshaft etc. all required machine work completed as necessary and put back to factory specifications. The word itself "rebuilt" is not acceptable as there are too many gray areas involved. Unless you are discussing engine accessories. I hope this is helpful to you.

03-16-2013 04:05 PM
Re: defining "rebuilt"

If you are looking at an engine that has been "re-built", as mentioned earlier, anything short of a very detailed invoice can be guess work. If an existing engine needs work a "Factory" re-build, from an established engine manufacturer, sometimes called "long" or "short" blocks, may be about as close to a new engine as you can get. Not sure if any, or many, sailboat engine makers or their dealers offer these?

If the engine has to be re-built on it own, I would suggest going to a WELL established dealer or MAJOR, well established shop. I think, most always, you get what you pay for.

Paul T
03-16-2013 01:06 PM
Re: defining "rebuilt"

Originally Posted by Minnewaska View Post

Yes, it must be removed to fully re-build, but a lot of big things could be done with it in the boat. If you don't see a brand spanking new paint job, I would be sure it wasn't recently "re-built". Then I would probably run from it, as the owner seems to have a disability with the truth. I get like that.
Have a real good look at that "shiny new paint job" too to try to ensure that it wasn't ONLY painted up shiny just to dress it up...
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