Reliable Old Diesel engines

[mvweebles]

Originally Posted by Scorpius

Raw water or heat exchanger? Neither! Keel cooling rules! No salt water coming into the boat. No screen or filter to plug up with jellyfish or plastic bags, etc. No salt water pump. No heat exchanger or associated pieces to fail. Able to run the engine if aground without sucking sand, etc. into the system.

Can you name one dry-exhaust sailboat built within the last 75-years?

I've run several dry-stack trawlers. The list of disadvantages with dry-stack is pretty long, long enough that one owner I know who is on his third Nordhavn (a traditionally dry-stack build) opted for wet exhaust on his 68-footer. The disadvantages that drove his decisoin? Noise; expensive mufflers; keel-cooler fouling, especially in warm waters; inaccessible keel cooler compared to easy access to heat exchanger inside the boat; soot on the decks (and sails I suppose); and heat generation to name a few.

I've been on a couple hybrid systems where the heat exchanger is effectively moved to a keel cooler but there's still a raw-water pump that discharges to the exhaust to cool the exhaust.

[Statistical]

Conditions and maintenance matters a lot more than hours and hours matters a lot more than years. Maintenance can be hard to verify but the condition of the engine bay, bilge, hoses, and electrical wiring can tell you a lot. Some engines are loved and some aren't.

That being said I would be very critical of a boat with 40+ year motor. Not a deal breaker but I would be looking over it with a critical eye. It might be great or it might be a money pit that you eventually tear out

The good news is the kind of diesel motors found in sailboats are about the simplest motors on the planet. There isnt that much too them especially the older smaller ones. As such it lasting 30 years and 20,000 hours is very possible and then a rebuild and it could last another 20 year or 10,000 hours more.

[Hoodsail]

I have a 1978 Westerbeke W30, 4 cylinder-25hp diesel. Owned her for 7 yrs and it may have been rebuilt in 1990's, but no receipts from prior owner so assuming engine is original. Have replaced alternator, exhaust elbow, racor filter, muffler & hoses, both belts. Annually replace oil filter/oil. Runs like a champ-didnt start once because water in fuel. Would get a compression test across all cylinders too...oil analysis okay, but more valuable if one of a series (does current owner have one?) to compare. On engine to do list - replace all 4 engine mounts..

[Bowdrie]

Originally Posted by mvweebles

Can you name one dry-exhaust sailboat built within the last 75-years?

Only an example of one that I've had first-hand experience with.
A friend of mine has a 52' Sutton steel ketch.
The keel is hollow, the lower part of it is ballast, the upper part is one big tank section that holds ~75 gallons of coolant, suitable plates are bolted on to allow access for cleaning etc.
I suppose one might call it "keel cooled"?
The dry exhaust goes up the mizzen mast, (both masts are steel,) the whole shebang has been working well since the '60s when the boat was built.

[Scorpius]

Originally Posted by mvweebles

Can you name one dry-exhaust sailboat built within the last 75-years?

I've run several dry-stack trawlers. The list of disadvantages with dry-stack is pretty long, long enough that one owner I know who is on his third Nordhavn (a traditionally dry-stack build) opted for wet exhaust on his 68-footer. The disadvantages that drove his decisoin? Noise; expensive mufflers; keel-cooler fouling, especially in warm waters; inaccessible keel cooler compared to easy access to heat exchanger inside the boat; soot on the decks (and sails I suppose); and heat generation to name a few.

I've been on a couple hybrid systems where the heat exchanger is effectively moved to a keel cooler but there's still a raw-water pump that discharges to the exhaust to cool the exhaust.

My Scorpius has a dry exhaust and keel coolers - and I love the set-up. The keel coolers are big enough (and the engine small enough (a 48 hp Isuzu C240) that I've never had an overheating problem with growth or anything else interfering with them - even in the tropics. Scorpius is steel (only 40 years old, not 75) and the keel coolers are simply lengths of angle iron welded to the side of the box keel. It makes it nice and easy for cleaning and painting. No problem with the dry muffler. It's an automotive one bought from a muffler shop. A little stretching and a little welding and it fits like a charm. I'm still on my second one since the system was installed in 1989. Most of the rest of the dry exhaust system is 2 1/2" galvanized water pipe. The exhaust discharges at the waterline right beside the engine. I've never had a problem with soot. Yes, it is a little noisier, and yes, the engine room (box) gets pretty hot, but it has a substantial blower that runs anytime the engine is running.

That keel cooler (and hydraulic anchor winch) was a life saver when we were blown ashore in Belize by a squall. We ended up beached, heeled right over, in 4'+ of water (Scorpius draws 6). We set three heavy anchors (one borrowed from our buddy boat who led us astray getting into the anchorage) fanned out on one rode and, with the hydraulic anchor winch, rolled Scorpius over and dragged her out into deeper water. With the keel cooler there was no risk of sucking sand into the engine cooling system - so we didn't have to worry about that!

Here in the Pacific coast of Canada, keel coolers are standard on small commercial boats (fishboats, tugs, workboats, etc.). I think those guys know what they are doing. I take a lot of my equipment cues from them (radios, radar, hydraulic anchor winch, etc.).

[barnakiel]

An old engine that has not been used much is not a great thing - engines not used much get all kinds of problems. Engines like to be used actually.


An old engine that has been used a lot is not a great thing either - engine parts move and get worn. So an old engine much used will have parts worn. No good.


Now an old engine that has been well used and maintained (top jobs, decarb, new rings, etc. etc. may still have plenty of life in them.


You can run a series of tests to see what condition an engine is in. Hire a good local mechanic and get a written report and ... hey ... you may get lucky.


b.

[HeinSdL]

Originally Posted by Scorpius

Raw water or heat exchanger? Neither! Keel cooling rules! No salt water coming into the boat. No screen or filter to plug up with jellyfish or plastic bags, etc. No salt water pump. No heat exchanger or associated pieces to fail. Able to run the engine if aground without sucking sand, etc. into the system.

Agreed, very compelling arguments. But that solution is also an example of over engineering and hence expensive. My boat has a keel which gets bolted on and an engine which gets bolted in and away you go. Keel cooling on my boat (not any old mickey mouse boat) would probably triple its price and hence make it unaffordable. So I'm 'stuck' with a yanmar and saildrive, both of which receive a lot of care, and they operate beautifully. Not that old, but still moving towards 30 years. They're spotless too, visually. OP would have no issue.

[Scorpius]

Originally Posted by HeinSdL

Agreed, very compelling arguments. But that solution is also an example of over engineering and hence expensive. My boat has a keel which gets bolted on and an engine which gets bolted in and away you go. Keel cooling on my boat (not any old mickey mouse boat) would probably triple its price and hence make it unaffordable. So I'm 'stuck' with a yanmar and saildrive, both of which receive a lot of care, and they operate beautifully. Not that old, but still moving towards 30 years. They're spotless too, visually. OP would have no issue.

Over engineered? Perhaps. Expensive? Definitely not. Built with an automotive muffler, angle iron from an old bed frame, off-the-shelf steel water pipe and a short length of SS flex.

The labour was pretty cheap too. It was all put together by a handyman friend on Lasquiti Island. And if you know Lasquiti Islanders, they're pretty handy. My friend was from a fishing and "gyppo" logging family who charged me $10 an hour (in 1989) to put the new-to-me (rebuilt) Isuzu in with the dry exhaust system. Also the hydraulics. And yes, we're still friends.

[jharding]

When you buy a boat you get a survey, I would also get a separate engine survey and rig survey. Don't get a cheap survey, you need to pay good money for a good survey.

[Kettlewell]

I have a 46-year-old Perkins 4.236 that is approaching 5,000 hours and runs great except for a leaky water pump I need to replace this winter. Has never failed to start nearly instantly. One time in the middle of the winter while hauled out I was working on the electrical system and I wanted to check if the starter circuit was working so I just touched the starter. Big mistake! The engine instantly fired up while on the hard and blasted out antifreeze all over the area. Keep your fuel clean, change filters, change oil, make sure the cooling system is getting water, and diesels will run forever.

[pcmm]

My boat has a late 90's era Yanmar 4JH2E that I installed to replace a siezed old perkins that I didn't want to deal with. In the 9 years I've had it in the boat, I've had 3 issues. 2 were 100% user issues, I forgot twice in the spring to open the fuel shut off at the tank and while the engine started right up it started to stumble after a few minutes of not being able to get fuel. Opening the fuel shut of fixed the problem. The only other time was this summer when the relay for the shutdown solenoid got stuck on and burned out the shut of solenoid. Engine didn't want to start (because of fuel being shut off). that time I actually had to spend $80 for an amazon replacement solenoid and $8 for a new relay.

Other than that for the last 9 years, its started on the first crank every single time. Great engine, super reliable. I give it a good clean every spring, check belt tension regularly. Before each usage, I check the oil level. coolant level and trans oil level. Regular Oil changes and -100c winterizing every year, a little pat on the engine, and a thank you before winter layup and its been a great smooth reliable engine.

Age of the engine is one thing, but how its been cared for is far far more important! I've seen boats with 30,40,50 year old engines that were so well cared for that you could eat breakfast of the valve cover. I've also see 4-5 year old engines that have seen zero care and maintenance on that look prehistoric and shakey!

[mvweebles]

Originally Posted by Scorpius

My Scorpius has a dry exhaust and keel coolers - and I love the set-up. The keel coolers are big enough (and the engine small enough (a 48 hp Isuzu C240) that I've never had an overheating problem with growth or anything else interfering with them - even in the tropics. Scorpius is steel (only 40 years old, not 75) and the keel coolers are simply lengths of angle iron welded to the side of the box keel. It makes it nice and easy for cleaning and painting. No problem with the dry muffler. It's an automotive one bought from a muffler shop. A little stretching and a little welding and it fits like a charm. I'm still on my second one since the system was installed in 1989. Most of the rest of the dry exhaust system is 2 1/2" galvanized water pipe. The exhaust discharges at the waterline right beside the engine. I've never had a problem with soot. Yes, it is a little noisier, and yes, the engine room (box) gets pretty hot, but it has a substantial blower that runs anytime the engine is running.

That keel cooler (and hydraulic anchor winch) was a life saver when we were blown ashore in Belize by a squall. We ended up beached, heeled right over, in 4'+ of water (Scorpius draws 6). We set three heavy anchors (one borrowed from our buddy boat who led us astray getting into the anchorage) fanned out on one rode and, with the hydraulic anchor winch, rolled Scorpius over and dragged her out into deeper water. With the keel cooler there was no risk of sucking sand into the engine cooling system - so we didn't have to worry about that!

Here in the Pacific coast of Canada, keel coolers are standard on small commercial boats (fishboats, tugs, workboats, etc.). I think those guys know what they are doing. I take a lot of my equipment cues from them (radios, radar, hydraulic anchor winch, etc.).

Sounds like an attractive setup. Crazy it's not standard in production boats, huh?

As far as the commercial guys knowing what they are doing, many are wet exhausts too, especially in warmer waters than PNW. 20-years ago dry stack exhaust was the holy grail amongst passagemaker trawlers. Second and third generation owners frequently revert to wet exhaust as there are many disadvantages to dry stack in a recreational application. Most knowledgeable owners are ambivalent - exhaust type is not a deciding factor as they understand the pluses and minuses of esch. But there are some (usually inexperienced) who have drunk the Kool Aid on dry stack.

[BlueH2Obound]

Our first two large(er) boats were keel cooled. The first, a 34' Ed Monk SR design, used a 6 cylinder Nordberg Knight gasoline, flat head engine. Keel cooled with bronze piping using a through hull fitting. Two pipes with a 180 degree turn around at each end, the through hull being placed near the engine, about mid-way along the cooler. It DID have a raw water injection in the exhaust between the exhaust manifold and the wet muffler. Non-pressurized system, with two pumps, one on the engine for the fresh water (antifreeze) re circulation, and one bronze gear type pump, belt driven off a pulley for the exhaust raw water injection. No cooling issues in our 8 years of ownership.

The second boat was a Grand Banks 36, originally powered with a Ford Lehman 120, and repowered two years prior to our purchase with a Cummins 6BTA, 210 hp diesel engine. Still used the original keel cooler. No issues with that one either.

Never sucked a plastic bag, never had to worry about stripping a "rubber" impeller, never had to periodically change the impellers, didn't have sea strainers to monitor and clean out periodically. Didn't have to worry about two separate cooling water loops, just the one. Never had any overheating, even in warmer waters of Hawaii. Didn't worry about drag, since hull speed was < 9kts on both boats.

Hmmmm, yep, our current boat(s) would be keel cooled if I had a choice. Well, actually, our current (main) boat has a Gardner main engine, and draws off of a sea chest. Both the fresh water cooling pump, and the raw water cooling pump are gear driven off of the main engine. Both use bronze gear type pumps. The fresh water pump, per the data plate on the pump, requires lubing every 2,500 hours. The raw water cooling pump uses a grease cup, which the manufacturer recommends turning 1/4 turn "periodically", not to exceed one full grease cup in less than I believe, 750 engine hours . . . . Pretty much maintenance free

The auxiliary engine, an Isuzu, has a gear driven fresh water cooling pump, and a butyl (or nitrile) impeller, which I replace annually.

Speaking of reliability, our Gardner 8LXB was manufactured in 1978. The engine currently has between 6,500 and 7,000 hours on it, of which we've put about 1,600 in the last three years. The first major maintenance recommended by Gardner is to remove the heads, and cylinders, replacing the O-rings in the cooling system in the cylinders and heads, as well as new cylinder and head gaskets. The recommended interval is 30,000 hours.

[MicHughV]

Years and years ago, I had a small Volvo diesel in my boat..a Volvo MD7A.

I could not explain how it happened, but the engine got filled with seawater from top to bottom and got completely locked up.

Being in the middle of nowhere, there was little I could do, but I set about removing the cylinder heads, sucking the seawater out, and then banging on the piston with a sledge hammer to get it to move.

After which, I put everything back together, using the original head gasket and everything else and gave it some fresh oil.
With more hope than anything, I turned the key, and damned if it didn't start right up.

A few more oil changes and I was back in business. Engine smoked a bit, but didn't burn any oil I could tell and it ran for years after.

I write this as a testimony that marine diesels are built extremely tough. I've had several diesel engines since, and with just basic maintenance and oil changes, never had any problems worth noting.

[hpeer]

As a MD7a owner I approve of this post!! LOL