Boat engine goes out of control on first test run

***UPDATE AND CLARIFICATIONS IN DESCRIPTION BELOW***
We're running a replacement engine (a 1975 SABB diesel) for the first time during a rebuild. Things go badly, we're forced to replace several parts, and investigate the cause. We cannot proceed with the refit of Nibiru unless this engine runs properly! Subscribe to follow our progress on this journey!

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*Update and clarifications:*
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Hey all, so we didn't think this would blow up like it did, but here we are. Really appreciate you all coming to watch our blunder, it has been a lot of fun. We wanted to take the time to elaborate / respond to sentiments we've been seeing more than once:

*_"Don't quench the copper! It hardens!"_*
The old guy has been annealing, quenching, working metal professionally for over 30 years, and as a hobbyist for nearly another 30. We know all about it, this is *very far* from the first time he has annealed metals. Annealed copper can be cooled in water just fine, it was still soft, and the seal is currently perfect. *The engine has been run repeatedly over the past couple months without a singular sign of leakage.* The quench in the footage is *not* a necessary step to the process, but in that moment we simply wanted to get on with it, so we cooled it quickly. We may not be paragons of engine safety 🤣 but _he_ does know his metals.

*_"You say that, but the head gasket is clearly still leaking, it's right there in the video!"_*
Nope, the head gasket is sealed perfectly. The footage is catching tiny puffs of exhaust coming from the fuse socket _just_ above the head gasket (it was a little loose). Also there is steam from the water cooling intake boiling over between cuts. The steam is being fanned around by our salvaged air cooling flywheel. Sorry we didn't clear that up.

*_"You call that a rebuild? The thing is filthy!"_*
So the video could have been worded A LOT better, that's our bad. What you're seeing leading up to the big event is a rebuild at 90%, and us making some dubious assumptions by running her. The engine at present is clean, painted, beautiful, and like we've said: has been running in the shop once or twice a week just for fun :) There will be more footage coming before we install her in the sailboat.

*_"... Okay well, what did you do up until this point?"_*
and *_"where did this engine come from? What state was it in?"_*
Sadly we started filming at the end of the rebuild, we would have loved to show the process leading up to the test runs.

This engine was a basket case we were given through friend, she came out of a derelict sailboat, the make and size we don't know. We are actually not the first to attempt rebuilding this engine, as it passed through several hands that gave up on it, ultimately.

After it arrived in our shop the rebuild process (before this video) involved:
1) Assessing the work done by previous owners (was chaotic to say the least).
2) Reseating the head valves.
3) Replacing the transmission.
4) Pulling the piston, cleaning up the parts.
5) Installing a new flywheel. (Harvested from an air cooled engine we had lying around.)
6) Cleaning the ancient tar-like oil out of every little nook.
7) And last but not least: Repairing a giant crack in the block.

*_"What was the cause?"_*
The cause was a malfunctioning governor, with an incorrectly assembled fuel injector compounding the issue. We have since determined that the fuel injector documentation was in error. We attempted to corroborate the information online, but we were unable to clarify the situation as our time scouring the internet produced incorrect information as well. The fuel injector was providing at least 2x the necessary fuel. In the strictest sense, this wasn't a diesel runaway as it wasn't being provided an unintended fuel source. But the supply of fuel was beyond out of control.

Thanks for checking our video out guys! We hope that clears some stuff up. It really is a shame the filming process didn't start sooner, but we felt like we wanted to scrape something together and get it up just to share in our learning process. This video is as much a lesson of what not to do as anything.

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Corrections:
00:08 - This was incorrect. At the time of the this recording the engine was *not* done being rebuilt. This was the result of a miscommunication between editor and shop, sorry about the confusion. We're going to do a better job in the future. See the description for more.
01:14 - Since uploading we determined this was not a diesel runaway as the engine was not being provided an unintended fuel source. The the problem was with the governor. Additionally, the fuel injector was also assembled incorrectly following incorrect original manufacturer instructions. As a result we estimate the injector was providing at least 2x the necessary fuel.

#boatengine #sailboatrefit

[HansenBoatworks]

Hey guys, after some careful consideration we decided to reupload this video. We weren’t satisfied with the render quality, could have explained the situation better, and made several small errors throughout. So despite all of the wonderful comments, and attention the video was getting, we felt it would be best to put up a more polished effort for the long term.

We’re really quite sorry about this, and appreciate all the feedback we received. Thanks!

[myself]

Friend had a turbodiesel where the turbocharger oil seal started leaking engine oil into the intake, and it promptly ran away, burning its own oil. There wasn't a quick way to block the intake, and the flywheel's intersected with the driver's cab, so the driver did the smart thing and GTFO.

It ran well above redline for several minutes, filling the building with smoke until it burned enough oil for the oil pump to suck air. Evidently there was enough oil left in the bearings and journals that the thing somehow avoided seizing up as it revved down from the stratosphere. By this time everyone in the area had turned out to watch, and once the danger had passed, they set about opening all the windows to air the place out.

They fixed the oil seal issue, replumbed the intake so it was easy to choke it out in case it happened again, and started it back up. Reportedly the engine was completely unbothered by the ordeal and was still running without complaint years later when my friend left the company.

As a result of hearing this story, I've never let myself get near a diesel engine without a plan to block the intake!

[gmcevoy]

As a pro mechanic, I can say with great certainty that it took balls of steel to stay there with a cool head, act accordingly and wait until it actually stops. Well done, gentlemen.

[ericalfers]

Mid 80's I had an older type of SABB single cylinder diesel engine in my sailboat. She never failed me, easy to maintain and very reliable. Good to see this engine again after all these years.

[Sailingon]

My friend's boat has a sabb its ability to remove loose teeth with the vibration is legendary. Not sure of its age but never fails to start and sips fuel.

[flexiblebirdchannel]

Great that you do not only show the runaway but also explain what needs repair.

[fourfortyroadrunner]

Best way for safety is to pre-plan a way to plug the engine air intake--just like the old Detroits

[dr.zarkhov]

Reminds me of a story a friend told me about his older brother that had joined the Navy. Shortly after rebuilding a diesel engine, he was showing some superiors it running and the same runaway happened. Cutting the fuel wasn't working so he ripped off his t-shirt and jammed that into the air intake to stop it. Their father was the head machinist at a local boatyard. Loved heading over to that shop which was right down the street from where I grew up.

[dingo]

Oh you want me to go huh? You want me to GO??

[vinny]

I've seen quite a few people try to stop a diesel runaway by cutting the air intake and it's remarkably difficult, partly because a proepr runaway involves it taking fuel and air from places that it's not supposed get them from. A decompression valve is probably the best option because that's the only thing that you actually have full control over.

[NeilTreneer]

Got what is probably the last one supplied from the factory. The then UK agent tried shortly after to order another and was told they no longer made them. That was 2001. It is still in the boat, used for commercial fishing. Good quality, simplicity, you cannot better!

[leeross]

I know some subaru owners who wish it was that easy to change a head gasket :)

[RingingResonance]

beautiful work and videography. I love how you captured the character of this engine with the closeups of the colorful layers of chipped paint combined with an excellent choice in background music.

[infocus-media]

This makes me think of my little brother, he was about 6 years old and he was on the tractor with one of out workers. The worker stopped at a gate and he got off and opened the gate but as he walked back my little brother had by magic put the tractor into gear and the throttle next to the steering column was pushed up to about idle, so when the tractor went into gear it started running forward. I will never forget the excitement in his face as he yelled to me, "look at me, look at me" And for a second I thought but there is something wrong with this picture, a 6 year old in charge of a 5 ton tractor that is moving forward and will only stop if it runs into something VERY solid. By now the farm worker was running like hell to catch up with the tractor so he can stop this monstrosity that is destroying everything in its way, and to make matters worse is that every single time the farmworker fell flat on his face my little brother was gasping for air as he laughed. So there the tractor went with this guy chasing after it, just like a Laurel & Hardy movie. By now, there were pigs running around and all of the milking cows were standing by the fence josteling for the best viewing spot (Cows are very inquisitive by nature) and the old barn (almost 120 years old) were next to get some of the demolition work done to it. But to every body's amazement he leaned forward and pulled the gear lever back into nuetral and the steel giant gave a huff and a puff as it came to a stop right onto of an anthill. Now that is what I see when that engine turned from a hit and miss engine to a roaring beast, best thing to do is grab your lunch box and get the hell out of there, she will stop as soon as the juice runs out but don't forget to anchor that baby to a huge metal spike in the ground before she gets to the Pigs or even worse, the Cows who will think it is Christmas when they see this engine jumping around and dry every single drop of milk out of there udders at least until Friday. LOL!, Have a nice day!

[greatwhitenorthcanada]

Anyone who has had a diesel start running away knows how dangerous they can be. Heavy parts spinning way above there normal speed is a recipe for disaster. Had an excavator that started to run and only stuffing a coat in the intake stopped it. Not easy to get to, and lots of noise of things getting ready to go wrong.
Nice teardown and showing what needed to be fixed.

[walterwhite]

Somnething about repairing or restoring a machine is super calming. I can´t put my finger on it, but everytime I get to repair something, I get really relaxed. And watching someone do so has almost the same effect. :)

[gregfarmer]

Geez, plenty of Monday Morning Quarterbacks out there. I saw two older guys kicking around an old motor to get it running. I would wager these same "old guys" were from an era where shit got done, with maybe a hiccup or so, but it got done. And didnt require a series of "team meetings" to discuss how, who, when, what, why before even a spanner was turned. I loved it, you reacted accordingly and no one got killed. Thats a good day in my opinion. Keep rocking you two, life is an adventure and I would like to think you had a beer and a laugh together afterwards resolving "how did shit happen" . 10/10 :)

[ptonpc]

It sounds a lot happier the second time.

[robworrall]

Lovely sounding diesel combustion knock when this engine is fast idling after rebuilding it, lucky the run away situation happened with experienced hands around it too OMG!

[ben_doom]

In Germany we're using a "Notfall-17er" for such issues. Simply a wrench which fits the nut on the high pressure fuel line to the injector to loosen it in case there is a fuel pump driven runaway. On most engines the correct size for that thing is metric 17. If the fuel line is loose, the fuel will leak out and not enter the injector, stopping the engine.