SailNet Community - Reply to Topic

   Search Sailnet:

 forums  store  


Quick Menu
Forums           
Articles          
Galleries        
Boat Reviews  
Classifieds     
Search SailNet 
Boat Search (new)

Shop the
SailNet Store
Anchor Locker
Boatbuilding & Repair
Charts
Clothing
Electrical
Electronics
Engine
Hatches and Portlights
Interior And Galley
Maintenance
Marine Electronics
Navigation
Other Items
Plumbing and Pumps
Rigging
Safety
Sailing Hardware
Trailer & Watersports
Clearance Items

Advertise Here






Go Back   SailNet Community > On Board > Gear & Maintenance > Runaway diesel
 Not a Member? 


Thread: Runaway diesel Reply to Thread
Title:
  

By choosing to post the reply below you agree to the rules you agreed to when joining Sailnet.
Click Here to view those rules.

Message:
Trackback:
Send Trackbacks to (Separate multiple URLs with spaces) :
Post Icons
You may choose an icon for your message from the following list:
 

Register Now

In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Click here to view the posting rules you are bound to when clicking the
'Submit Reply' button below


Additional Options
Miscellaneous Options

Click here to view the posting rules you are bound to when clicking the
'Submit Reply' button below


Topic Review (Newest First)
08-16-2013 11:50 PM
Cap-Couillon
Re: Runaway diesel

Have used the CO2 fire extinguisher method to kill a runaway. It works, but make sure its CO2 not dry-chem. Just as an aside, here is a vid of a 1930's Rapp Semi-Diesel (2 stroke) running away from an overfilled crankcase.
08-16-2013 08:14 PM
foggysail
Re: Runaway diesel

Years ago I had a run away in my Hunter 30 powered with a 12HP Yanmar better suited for rice patties. I over filled the crankcase. Started the engine, things seemed fine and then it started to race even though I pull the fuel lever all the way back

Yeah, I knew what could happen so I quickly put the transmission in gear and let the boat do wide circles until the run away stopped. No damages
08-16-2013 07:12 PM
TQA
Re: Runaway diesel

The two scenarios for engine runaways are

1 Pneumatic governor usually the single pipe. I have seen an old Mercedes boat engine with one of these. If the pipe breaks or the diaphragm fails they will runaway. You can pull the stop control and the engine will stop.

2 Any engine where the crankcase breather feeds into the inlet manifold. If there is any significant frothing of the crankcase oil and it passes through whatever trap is fitted you get a runaway. Pull the stop control and the engine will not stop you have to cut off the air supply.

If I got a runaway and could not get to the air inlet to stuff a rag in I would pull the decompressor if my engine had one. What ever damage would be done would be less than the catastrophic failure you get from a runaway. Worth doing a dry run to find if you need to remove something to block the inlet. Perkins diesels often have a filter that I would need to be removed before applying the rag.

While I have never witnessed a runaway that actually resulted in an engine failure that was catastrophic I have taken the breakdown truck to a Commer 2 stroke that had run away and so had the driver. There were bits everywhere and one of the pistons was embedded in a brick wall many yards away.
08-16-2013 02:39 PM
goehner2
Re: Runaway diesel

We had an old carrydeck crane with a diesel engine that became notorious for not shutting down or overrunning. We installed a ball valve just down stream of the the air filter so we could stop the engine. If your filter housing is threaded to the air intake tube, it would be an easy install, assuming you have room for the valve.
08-16-2013 10:37 AM
Melrna
Re: Runaway diesel

I would not use a rag as it can get sucked up and destroyed into the engine. Instead I would use a piece of wood or something hard over the intake.
08-16-2013 12:35 AM
zeehag
Re: Runaway diesel

Quote:
Originally Posted by chucklesR View Post
Run away on oil has happened to me once.
I put too much oil in while changing it (boat wasn't level while on the hard), then on my first time out decided to test throttle to max RPM. Frothed it right up. Huge clouds of blue smoke and no throttle control all of a sudden.

The governor doesn't do a thing, it only shuts off/restricts the diesel fuel - so the engine continues to get a full load of 'fuel' from the oil froth.
The fuel shutoff (mechanical and electrical both) does exactly as much good as the governor, none.

Since it's got PLENTY of fuel there and air coming in the engine just does what it is designed to do and runs at full out to use all the fuel coming in, and of course more fuel means higher rpm.

The only way to stop it is to choke air (a rag in the intake) or decompress the engine by tripping the lever on the engine.
You'll need to recognize the condition of run away quick - spinning parts at 4000+ RPM can quickly destroy an engine.

Having had it happen to me just once was enough. I keep a rag zip tied in the the air intake area as well as a zip tie (red) on the decompression lever. It's hard enough to stick your face and hand into a engine compartment with an engine that might be exploding in seconds - doing that and then having to look around for a rag/lever doubly sucks.
if the problem is with the fuel delivery system, as mine seems to have been,maybe, the engine will stop running when all injectors are cracked. my engine is perkins .. they are difficult to cut air.

runaway diesel is also caused by engine using its own lube oil to run and continues to increase rpms until overheat and detonation. this one must cut off air flow or ditch compression so it stops or it will detonate and you can lose boat. this cause is not fixed by cracking injectors, i have been advised.

this is mainly caused by excessive blowby, excessive cylinder wear, ring failure...worn, broken, cracked....
mine so far seems to have been fuel delivery initiated.
08-16-2013 12:07 AM
Bob142
Re: Runaway diesel

As long as you are not in danger of hitting anything you are better to leave it turning the prop as disengaging will allow the engine to rev higher and faster...
08-15-2013 08:07 PM
steel
Re: Runaway diesel

I don't think anyone mentioned this, but you can use a CO2 fire extinguisher to stop a run away diesel.
05-22-2013 11:25 PM
Capt Len
Re: Runaway diesel

So a large eastcoast dragger is coming into a crowed port. The oiler, trying to get a head start on shore leave has removed,cleaned and rinsed (with diesel fuel) the air filters .He re installs.Wow. suddenly engine is way past governed RPM. Take her out of gear and probably disintegrate or do a fancy two step in small places. Excessive RPM can be interesting. My best experience was a friends hot chevy . Carb linkage over centered and pressure plate bounced off the pavement , came back up through the radio , dashboard and windshield into the night.Presence of mind (turn off the key) would have helped.
05-22-2013 10:14 PM
captbillc
Re: Runaway diesel

running away means the engine continues to speed up . if you don't stop it , it will fly apart. it is a scary situation .
This thread has more than 10 replies. Click here to review the whole thread.

 
Posting Rules
You may post new threads
You may post replies
You may post attachments
You may edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On


All times are GMT -4. The time now is 08:40 AM.

Add to My Yahoo!         
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.1
(c) Marine.com LLC 2000-2012

The SailNet.com store is owned and operated by a company independent of the SailNet.com forum. You are now leaving the SailNet forum. Click OK to continue or Cancel to return to the SailNet forum.