Reason for marine diesel engines runaway

About 83.28 jillion to one unless you get cold valves.

Not for BEAU,
He just increased his odds a million fold by that post.

Kafue

Is there some "Australian Ritual" i can use to erase the self imposed curse??

Hahaha,
I heard something about running from stern to bow wearing nothing but heavy lube oil (straight 40W) and waving a bent stick!
Good luck Mate!

Kafue

If you've ever seen me changing my hot oil, you know that I've tried that, so maybe I'm safe. Thanks

I have been present at a few "runaway" diesel engines both older mechanical types. Niether engine was stoped by rags as a matter of fact I watched them both eat them with not even a stutter. Covering the turbo inlet with a solid object was the way to stop them.
One engine even drew fuel through the closed fuel valves this did slow the engine back down to its rated no load speed after seeing it reach twice its rated speed. The turbos spun so fast the nuts came off the turbo shaft. It ate rags, towels, plastic parts buckets till a few metal paint can lids could be located.
After any work on mechanical governors and fuel pump system I now always remove the air filters and have the lids handy before start up.

no one wants to be around when something like this happens
Dyno run gone bad!!!!!!!!! - YouTube

I have no idea what happened, I was anchored near the boat then saw what looked to be the boat near me on fire. Turned out that one of the motors ran away, even with the fuel off, the motor kept going at full bore. Sorry I dont have more details...

So an older mechanical diesel was a runaway on diesel fuel which continued to be a runaway with the fuel valves shut? How long did it continue after the valves were closed? I know that my 16-92's can run for a bit at over 1800rpms when I close the valves- but not long- perhaps 15 seconds. Sucking enough fuel to continue fueling a runway thru closed ball valves? I'd have to see proof.
What was the end reason for the runaway on diesel in that instance?

Not ball valves but very old gate valves The reason for the run away was a fuel rack stuck at full fuel due to a faulty fuel plunger. The engine ran upto over 2800 rpm and after the valves where "closed" still maitained 1600 rpm till the air was cut off using the paint can lids. Sorry dont have a video of this as "proof"

A few years back DD blowers on turbo charged models used metal seal rings. Oil passage under certain conditions was very possible. Today all DD blowers, turbo or non turbo use teflon lip type seals.
I once saw a 6V-92 TA run away after a mechanic had set the rack. Mind you the turbo sits right on top of the blower next to the governor throttle and stop lever. The one mistake the mechanic made was he forgot to back out the buffer screw. When it started it went start to 3000 or higher rpm, just screaming. The tech tried to grab the stop lever, the turbo pulled his hand right into the compressor wheel, he lost 4 fingers and the engine never missed a beet. I shut it down with a large hammer, breaking off the fuel fittings.

Thanks. Gate valves I can imagine.

Don't forget the saucer of milk!

Ddc

I work on diesel engines and have seen 2 detroits run away and it is terrifying at least. Its nothing to juke about. Both times it was the air box drain valves were pluged and the engines took off after coming off idle and sounded like a turbine engine. These engines will run on anything, oil, fuel even antifreeze. The only way I could get them stoped was covering the intakes with a thick service manual and they sucked every seal in that was in the intake path. I've seen them kick rods out the sides and continue to run. I would hate to see this happen and poke a hole in the hull and sink. It's important to clean/replace the air box valves regularly.