Engine hours

[dodgeboatguy]

OK I will not argue and I may be wrong on this to but most standard alternators will put out close to peek amperage at a normal idle (with an apropriatrly sized shieve of corse) and much above that the voltage regulator kills power to the field windings so what is the reason for the high rpms and if you are not getting the power you need at idle why not a bigger crank shieve or smaller alternator shieve?

[FrankLanger]

Many of us warm up the engine for about ten minutes, then leave the marina and motor for about 15 minutes before shutting off the motor and raising our sails. We may motor periodically for several hours at a stretch on calm days. Is that enough to blow the carbon out, or is there something else we could do to minimize carbon build-up and keep our engines lasting a long time? That's assuming we're already doing the usual regular oil changes and other maintenance.
Thanks,
Frank.

[dodgeboatguy]

Good fuel treatments cant hurt and take it or leave it but I believe that it is good to run a motor wide open for a few seconds once in a while it raises combustion chamber temps and increases moving parts speeds IE pistons and valves to a point that it will help to break up an remove carbon deposits now I do not recommend this on an old motor that it has not been done to periodically as you may break something free that is bigger than will freely flow past the exhaust valve and could cause serious internal engine damage just what I do. And my experience is limited to agricultural and construction equipment and diesel pickups but my 820 hp 1138ft/lb Cummins/banks dodge thinks I know a thing or two about diesels. Also a good shot of propane or methanol does wonders for cleaning them out the thermal shock breaks that stuff rite up not recommended on just your every day small diesel though.

[Danny33]

2000 hrs is nothing for a diesal engine if its been matained properly.
Have a mechainc pull a oil sample out .,and have it tested ...he or she will or should know proper procedure. You can also pull the oil filter off ,cut it open at the seam ..pull the paper out like a acordean and read that also.
there is not much room to explan it all here . Its a old timer trick to cut the filter. ask around to see if anyone does it .

Diesels run off heat and compresson ( heance glow plugs on some ) They do not like to idel. and keep it to a minimum. they should be stepped up above idel once the temp gauge jumps off the cold mark.

Find the spot where the engine smooths out ( tach) thats where its operating efficently ,unloaded. The worst thing for them is ideling them for hours . that is the white smoke you see is unburned fuel. One can get into air temp and such...but that is genrally what is going on inside the combustion chamber.

Diesals love to pull . The unburned fuel in a microscopic manner will weep into the crank case and can prematurly wear the bottom end out.

I can go on and on.... Just the rough edge !

[chucklesR]

I'm guessing the 2000 hrs is a guess by the broker as the boat doesn't have a meter. That brand/make is a moderate use diesel made for tractors and such, but not rated for continuous use. Not the best but as such properly maintained it can be expected to last and provide service for decades still. The good news is there are many sources of spare parts and advice as they are common in the marina, and on land.

As to engine hours:

I ran my engine a metered 76 hours this year, sailing or over nighting every weekend with lots of afternoon/evening singlehanding. Far more than I usually do because it's a brand new boat. I don't charge batteries via engine as I have solar panels that do that.

If you know what you are about regarding diesel's - check the oil by pulling the dipstick and taking a look - it's not as good as a real analysis but better than listening to the engine run and looking at the exhaust smoke. If it's brand new oil it really doesn't tell you anything he may have changed it for the first time in 5 years just yesterday, but if it's crappy oil for any of the various reasons it tells you the owner has not maintained it, and doesn't even care if you know. Also, just look at the thing, clean engines and bilges go a long way towards longevity and indications of maintenance. Look for signs of recent cleanups -e.g. around the hard to get places look for old crud and stains in the fiberglass that indicate crud has been there for a while and just got wiped up.
Finally - the survey in and of itself will tell you general condition of the engine, you'll need to hire a mechanic to come down to the boat and give it a compression test and a full checkup to get a real report. At 100 a hour, it's worth it if you are worried and you can make your offer conditional on it.

[Cruisingdad]

Only have a moment so cannot respond in depth:

However, 2k hours is a drop in the bucket on a diesel. Do not let anyone tell you different. However, it does depend on how that 2k was used. If used idling to charge the batts for 2k hours, you will have a lot of carbon (poss scoring) and buildup and probs. Start up the diesel. Watch the smoke. As she warms up does it dissapear? Once warmed up, it should run smoothe and clean. DO not worry too much about start up smoke.

Sorry if all this has been mentioned. I am going too fast to go into much depth... but you also mentioned a mech survey. I think you should, personally. Cheap insurance policy on an exp diesel.

You can compression test the cyl(s). Check for even compression within 10% of each cylinder. HOt cylinders seem to run furthes aft closest to the exhaust. You can also check the exhaust back pressure which should be under 2psi on wot, on most diesels. 3 max, wot. You should verify with the mfg. Cheap test you can do yourself.

Just bought a 1988 with 3600 hours, runs great. THese are the things I look for. Also, check oil. If fresh change, I would be concerned. If not, make sure a good black and not milky in any way.

Diesels are tough and liked to be run. Hours do not concern me. How they are spent does.

Make sense??

Take care,

- CD

[Valiente]

A slightly different point of view here, which reflects somewhat odd circumstances.

I have a motorsailer with ridiculously low hours. The engine is a 1988 Westerbeke 52, clean, corrosion-free and I bought it with 1,150 hours on it (I've put on 150 in 18 months, more or less on purpose to see how it goes with a load). It starts reliably, if requiring more glow plug on cold days, and "feels" good.

However, 20 years of 65 hours/year (of which I suspect several years were stuck at dock as a liveaboard) could mean crud and internal corrosion I can't diagnose. So I am opting for "exploratory surgery": having it torn down by a diesel mechanic to determine if the guts need replacement or modification. It's worth the price of even a borderline necessary rebuild to ensure, as much as possible, that I can put 1,000 hours/year on it during five years of cruising, starting next year or in '10.

My point? With a diesel, neglect and low hours can sometimes be at issue. I have no maintenance records prior to '05, nor do I have any proof of regular oil changes, filter changes, impeller changes and so on. The original hoses? Going. The gaskets and seals? Going. The working, original raw water pump and heat exchanger? Going, because they'll make good spares and this boat has never had salt water in it in any form.

Some general advice would be this: If you change oil every 100 hours or so, give it clean, filtered fuel, keep water from backing up in it and give it a good wipe down now and then, you should be fine. But the typical "warm up, 10 minutes at 1,800 RPM, then off" is not ideal for a diesel. Find reasons to run it for an hour or two at speed, or at least past 2,000 RPM. This will help to clear out the carbon and will warm the entire engine thoroughly. Diesels like to be left on once on, and I often wonder why the gas inboard has been so throughly eclipsed, as it is a better type of engine for intermittant use than a high-compression diesel, especially in cooler climates where cold starts are brutal.

If you suspect low hours, consider after you buy it changing out all the exhaust hose. If original, it's probably old and brittle, but more importantly, it might be heavily carboned in the way that an artery can be heavily clogged with plaque. New hoses and cleaned outlets and even a new waterlift will do your engine and your peace of mind great service. Most of my problems with boat engines have been with problematic physics associated with getting the water/exhaust mix out of the boat effectively. Solve this, and the clean fuel is usually your only remaining typical diesel issue.

[Rockter]

Val...

Why on earth would you want to strip a motor when there is nothing wrong with it? I will never understand this approach.
On an older engine, you can easily break something on the strip down, and once disturbed, getting it oil-tight again is not all that easy.
On the way down, the mechanic will say "Oh look at this, there is a bit of pitting here, and that thingummy looks like it might fail in the next 83 years... sign here, that will be $250,000.
An engine with 1300 hours on it? Nothing wrong with it? Not losing oil, not smoking, still starting reliably?
On a road vehicle, 1300 hours at (say) 50 mph is 65,000 miles, and that motor will not have run at constant load, or near so. It will have been throttled for gear changes, and there will have been endless stop-start cycles.

65,000 miles? 1300 hrs? Strip it?

It's nuts, Val. Nuts.


Rockter

[Rockter]

...and an engine survey is only as good as the guy doing it.

[Valiente]

Val...

Why on earth would you want to strip a motor when there is nothing wrong with it? I will never understand this approach.

Because it is 20 years old and in a cold climate where it is "winterized" five months out of 12. Condensation has corroded somewhat the valve chamber springs and rockers, and the seals and gaskets are...well...20 years old. Now, and not in Fiji three years from now, is the time to closely examine and measure to shop specs the internals of the engine. My experience, limited as it has been, suggests strongly that seldom-used diesel can develop the same issues as over-worked or improperly maintained ones. Also, as I said, I have NO record of how the beast was used or maintained prior to my ownership of the last 18 months (I'm the third owner).


On an older engine, you can easily break something on the strip down, and once disturbed, getting it oil-tight again is not all that easy.

I'm prepared for this and have avoided the "marine mechanic" aspect entirely. I'm using a diesel rebuild shop that does trucks, bulldozers and railroad equipment, not some guy with a garage and a leaky air wrench.

On the way down, the mechanic will say "Oh look at this, there is a bit of pitting here, and that thingummy looks like it might fail in the next 83 years... sign here, that will be $250,000.


A complete rebuild will cost $6,900 in Westerbeke-sourced parts (including a new heat exchanger and Sherwood pump), with about two grand in labour. I don't expect that to be the case here, and I have the option of using Mazda rebuild kits at a fraction of that price.

An engine with 1300 hours on it? Nothing wrong with it? Not losing oil, not smoking, still starting reliably?

I had a faulty anti-siphon vent valve back water into the block a couple of times last year before I figured it out. 20 oil changes and three kerosene "rinses" later, I think I'm on top of it. But who knows whether this was a problem with the previous owners? I am going to circumnavigate, not motor from North to South Carolina in "the ditch", or in your case, up and down the Scottish lochs, with diesel repair at either end.

Getting a new engine would be about $22,000 with all the welding work to be done...this rolls my maintenance odometer back to zero. Besides, if the engine cranks, bearing, rings, etc., show little wear, then I know they are good. I abhor an informational vacuum, as would you if presented with a 1985 sports car with 15,000 miles on it: you'd be suspicious and worried about stale gas, rancid oil, fouled plugs, etc.

On a road vehicle, 1300 hours at (say) 50 mph is 65,000 miles, and that motor will not have run at constant load, or near so. It will have been throttled for gear changes, and there will have been endless stop-start cycles.

Were you a sailor on Lakes Ontario or Huron (where this boat has spent its entire life), you would know that is precisely the pattern of use here. Stop-start, short-haul, cold starts, no chance to warm the entire block, long stretches of being laid up in the damp winters. Even in Scotland, "winterization" probably consists of putting a work light in the bilges for the five nights of the year you get a hard frost. Here, it's different. Ask my colleagues who sail Lakes Michigan and Superior, where the winters are both harsher and longer.

65,000 miles? 1300 hrs? Strip it?

It's nuts, Val. Nuts.

I appreciate your comments, but having rebuilt a 30 year old Atomic 4 myself at about a tenth of the price of putting in a replacement diesel, I do feel somewhat qualified to make these calls. It's possible I could throw a new rod at any point in our extended cruising, but I feel the odds are significantly bettered than by taking an old, rarely taxed engine in a situation where I actually may need extended periods of motoring into real seas.