Kibbles and bits
 

Well here is a very bad ending for d24T that I thought I was going to install in my 240. I bought a rebuilt D24T complete with around 40,000 miles on it. I got it home, primed the injection pump with fresh fuel, and changed the oil. On Sunday I put it on the running stand, rolled it over till it had oil pressure. I preheated the glow plugs and fired it up, Started great. A few seconds went and the engine revved up to the sky and before I could shut it off, BANG!!! Smoke all over. Engine stopped faster then it started. So I was done for that day, thinking well I need a piston and a new head now, I wish! Pulled it apart last night, I pulled the valve cover off, #1 and #2 exhaust valves gone, valve stem From #2 popping back up in a new location. Pulled the head off, and holy crap, there was no piston in #1 cylinder, well there wasn't much of a #1 cylinder also. Connecting rod looks like a egg noodle. I pulled some piston pieces out of the engine block and some cylinder wall. I will try to post some pictures this week. And by the way, Timing belt(s) was intact in great shape and still on time when pulled apart!

Guy at the local diesel shop had a 740 D24 in when I was down there - apparently it had sat for years. When they started it up, it revved up fine, but would not fall - apparently there was something in the pump that had siezed so would not reduce the fuel supply on letting the accelerator off. Luckily it only hung around 3,500rpm.

Did you take your pump apart in any way? I've heard if the governer doesn't go back together correctly it can do the same when there is no load on the engine.

Would be interested to see the pics - don't imagine they are too pretty though!

I Didn't do anything to the pump, It was rebuilt along with the engine. This is not the first time a VE pump has done this to me. I bought two Cummins 6AT engines that sat in storage for years and both the engines did the same, but they held together. I believe when the VE pump have been sitting for to long the governor will get stuck in the start position and not let the engine idle down. I was hoping letting the pump sit for a week with some fresh diesel in it I would not come across this problem again. After a few days the VE pumps on the Cummins broke lose and operated just fine.

Pictures of d24t falure
 

Pictures of the carnage.

Oh mine.. Totally blown up..

Wow, that is incredible carnage! Don't think I'll bother messing with the governer on my pump after seeing that....

What a shame!

There is a failure mode that causes a runaway, stoppable only by blocking the intake.

Ball actuator at the bottom of the fulcrum lever breaks off, leaving the fuel collar uncontrollable. If the fuel collar slides into WOT or near-WOT position the engine will rev uncontrollably.

Member v8volvo had this happen; his main theory is that running w/ clogged fuel filter caused the internal vane pump to self-destruct somewhat, sending shavings into the rest of the IP, some of which lodged between the fuel collar and shaft, causing the fuel collar to seize on the shaft, breaking the ball actuator off the end of the fulcrum lever, the weak point.

De-energizing the fuel shutoff solenoid may not be able to overcome this. Actuating the manual fuel shutoff (auto trans IP) has no effect (linkage is effectively disconnected at the fuel collar in this scenario). Dumping the clutch (manual trans car) may not slow engine in time to avoid damage.

Now that this failure mode has been identified, for future bench testing, we should all make sure to have a suitably-sized wood (or similar) plate positioned ready to slap over the intake.

What are you going to do with it now?

From the time it started to the time it exploded was only approx 20 seconds. I had a piece of plywood handy, but there just wasn't the time. I'm not sure what I'm going to do with it, I will strip it down to nothing to save the usable parts and I might just scrap the block.

Don't beat yourself up over it. You would almost have to have the board ready to go in one hand, while starting the engine with the other. The good thing is that you were not hurt by any parts grenading out of the engine, which is a real possibility.

Which leads us to an exploded:o view of the IP, to show the parts I was talking about in my earlier post:

http://postimage.org/image/rmdi5o9w/

What I referred to as fuel collar they call Control sleeve

The fulcrum lever they call Governor lever

Shaft they call plunger.

Well it was close to having parts on the outside of the block. There is a crack in the block. If that was a 6.5 GM diesel I might not be here... ( I'm working on a 929 cast 6.5 with 78,000 miles that has six main web cracks) They will blow up just running normal...