Experimenting
 

I had the idea of pulling out the broken rods, and running the engine without cyl 3 and 4, and i think maybe this may work. If someone can do me a favor and unplug the 3 and 4 injectors [or ignition, but injectors would probably make more sense], and try running the engine. If the engine runs alright and idles, maybe rev it up for me to see if it'll work at all. And if both those check out, and you feel rather daring, drive the car on only the 4 cylinders? It'd be great if you could report back and tell me how viable an option this is. Because it seems like the only way i'll ever get a new engine for the car, is to drive it to pick it up. It's not a far drive, but it's still a few miles.

Also, since the rods are disconnected, and the pistons won't be moving at all, would this by any chance make it run better than the above situation? Perhaps maybe it would act as though it were a 4cyl? Or am I only dreaming? :)

I think GM has beaten you on this invention called Displacement On Demand (DOD). Your idea might work, but I'm not going to be the one to say you should go gor it. The idle will be jussssst a little rough. If you could get it to start at all. If it was 1 cylinder I would have more faith with your idea.

Actually, see it depends. I was fooling around one day, and decided to see how many cylinders the car could run on.. and it seemed that as long as cyl #1 was there, it could run on as little as 3 cylinders. But I never drove it like that, nor did I do it with a control [IE cyl #3 and 4]. I know it's possible on some engines, but I'd like to know if 3 and 4 is possible on the LN3.

Also added on here, maybe taking out the spark plugs to decrease resistance, and make the comparison more like my engine. Because the DOD that GM has, disables valves [which would also disable compression].

It might run, but you'd have a hard time getting enough power to get it into gear!!

Don't bother, and most yards will truck engines to you, I know mine did.

Not a bad thought, really. My main concern would be that #3 and #4 are right next to each other in the firing order, if I remember right. So you'd have fire, fire, nothing, nothing, fire, fire, (repeat). A situation where you had fire, fire, nothing, fire fire, nothing, (repeat) would be a lot better, I think.

I do know of a guy who made his own simple displacement on demand, which simply cut out the fuel injection to 3/6 of the cylinders (I think), and it worked. Didn't have enough power for the highway, but it was still fighting compression too.

I say hey, you like to tinker. What have you got to lose? ;)

JMFC: you bring up a good point, that's what I was worried about, but I am kinda being optimistic, and the way I look at it, it's fire fire fire fire nothing fire fire fire fire nothing :). I would just like to see if anyone wants to try this out for me, and if a good running engine can even do it. I'll probably try doing it anyways, just because it can't hurt.

As far as the hole goes, i'll probably just JB weld on a piece of metal, because it's not like the car has to go far, and all it would have to do is keep oil from leaking just enough to drive a few miles.

You know the original DOD only shut off injectors too. Worked, just not very reliable. It was in the 80s, when EFI was just becoming popular.

Im not sure if this will work but what if you use the parts you DO have and switch the broken parts around so you can choose which cylinders you want to disable so it will run smoother? You could run it on 3 cylinders if you wanted and pull the plug from the others, so the engine will run evenly.

phoenix: yeah i could switch parts around, but that would require the removal of the crankshaft and pistons. And by that point I could have half the engine out already, and the whole point would be moot. But that is a good idea.

That's going to work? :|

Lets look at it this way...

We have 3 cylinder engines... But it doesn't have to move 3 other pistons, rods, and the like...

We have DOD V8's... How does it function? Does it cut 4 cylinders at once?

In a V8 a cylinder is fired at every 45*, in a 4 Cylinder its every 90*... I'd make the assumption that you could do this with a V8( 5.3 DOD is great proof )... But I would think in the city at idle you'd get nowhere in a hurry... I could be dead wrong but just a thought...

On a V6, you want cylinders 1-3-5 running at least... But I'd think you'd need all 6 to get moving... And then the 3 cylinders that you do have running have to overcome the reciprocating mass of the 3 opposing cylinders, and that would have to include valve spring pressure, compression stroke and what ever friction would be created by the pistons being moved with the assoiated parts... I would honestly believe that it would be a task to overcome...

Again I could be wrong... But hey... :lol:

Almost forgot.... You were going to remove the rods... Not sure where I was headed... :roll:

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