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Mark The Homer

Engine Turning the Wrong Way -- Counter-Clockwise

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lol

I don't know. If I was reading this thread, I'd probably doubt it too. All I know is what happened. I was there. I saw it. I heard it.

If

a) the truck is moving forwards with

B) the tires turning forward and

c) the clutch pedal is completely out and

d) the transmission is in reverse,

I don't see any other possibility except the engine's crank was turning in the opposite direction -- unless the clutch plate was shot. But it's new and perfect.

So, if we agree with that, plus I tell you the ignition was on, AND the pistons were firing (and I know this because I heard them), then the engine running. Granted, it was being forced to run as I went down the hill, but I heard the engine, and it was running, and not all that badly. No backfires, no violent or even mild shaking or shuddering. It sounded a little differenet, a little odd, but that is all.

Then, when I reached the bottom of the hill and disengaged the clutch, the engine shuddered mildly, and the RPMs (as I listened) slowed down. And then it stopped after about 10 seconds or so. To me, that counts as "running." It wasn't running well, but it was running.

Upon restart, it ran MUCH better, and did not stall. But there was a new hiss which I didn't hear seconds earlier.

Impossible or not, there is absolutely no doubt in my mind that the engine ran backwards. I was there.

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my feeling is that chomerics is both right and wrong at the same time. I believe he's right that the engine won't run backwards, meaning it won't fire and idle correctly. What I imagine happened is that the weight of the car on the hill overpowered the push of the gear since it sounds like you weren't hitting the gas pedal (same as how a car on a hill in gear without the parking brake on can roll away). In that case, the engine would be spinning backwards, yes, but not running backwards. It's the same idea as pop starting a car that won't start. If you pop start a car that has no spark, it'll seem like the engine is running for a short time, but it's running because the wheels are turning the tranny and the tranny is turning the engine.

What I imagine happened is that, by easing the clutch out in reverse thinking you were in first, gravity overpowered the clutch and tranny and took you down the hill in gear. The engine may have burned off some residual fuel in the meantime as the crank was still turning so the spark plugs would have still fired, but that doesn't mean it was running per se. In this case, I think the transmission was driving the engine instead of the other way around. It died when you came to a stop because the transmission was no longer turning the crankshaft.

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I thought they only did that in the Southern Hemisphere.

I think water going down a drain does that in the Southern Hemisphere...not an engine.

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I think water going down a drain does that in the Southern Hemisphere...not an engine.
Hmm ... but have you considered the fact that Australians drive on the left side of the road?

As far as the original subject of the post, I think DCsportsfan nailed it - the engine may have been turning backwards, but it wasn't "running" backwards. The wheels were turning the camshaft backwards, so the spark plugs would still fire and the fuel would still go into the engine (with the air running the wrong way) so it might feel like it was running, but the engine wasn't really "running" because there's no way it could keep itself going with the timing completely wrong.

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As far as the original subject of the post, I think DCsportsfan nailed it -
Yes. I think so.

The only thing to add or remind is, the ten seconds after I reached the bottom of the hill and disengaged the clutch:

The engine was running on its own -- backwards. < --- that's really what I'm talking about in this thread.

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my feeling is that chomerics is both right and wrong at the same time. I believe he's right that the engine won't run backwards, meaning it won't fire and idle correctly. What I imagine happened is that the weight of the car on the hill overpowered the push of the gear since it sounds like you weren't hitting the gas pedal (same as how a car on a hill in gear without the parking brake on can roll away). In that case, the engine would be spinning backwards, yes, but not running backwards. It's the same idea as pop starting a car that won't start. If you pop start a car that has no spark, it'll seem like the engine is running for a short time, but it's running because the wheels are turning the tranny and the tranny is turning the engine.

What I imagine happened is that, by easing the clutch out in reverse thinking you were in first, gravity overpowered the clutch and tranny and took you down the hill in gear. The engine may have burned off some residual fuel in the meantime as the crank was still turning so the spark plugs would have still fired, but that doesn't mean it was running per se. In this case, I think the transmission was driving the engine instead of the other way around. It died when you came to a stop because the transmission was no longer turning the crankshaft.

Actually, it looks like you got it. I can buy the engine firing a few times in reverse due to residual fuel in the cylinder, and also running backwards. I can't agree that the engine will run in reverse, but I will buy that it will fire a few times and buck the car. . .which is what appeared to happen. Not having been there, it is hard to tell what happened from a description, but I believe it happened like you said, it makes perfect sense. :)

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I have a question about the whole thing, as I don't know anything about engines -

Nearly every Sunday, I hear Darrell Waltrip, when describing a NASCAR racer who has turned the car around, wonder aloud whether or not he "spun that engine backwards." Is that a mistaken description, or is it a mechanical possibility?

If DW's statement is accurate -

1: Mark's event is totally possible in the way described. The difference between the two situations is minimal: one is geared forward traveling backwards, one is geared backwards traveling forwards. The theory should apply across both situations.

2: The vehicle should be able to run for a very short period of time until it stalled, as is proven by in-car recordings during the races. I imagine this would be because there would be residual fuel and air left over by the time the next spark in the now backwards series came around, but that's just a guess.

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I have a question about the whole thing, as I don't know anything about engines -

Nearly every Sunday, I hear Darrell Waltrip, when describing a NASCAR racer who has turned the car around, wonder aloud whether or not he "spun that engine backwards." Is that a mistaken description, or is it a mechanical possibility?

I believe he just meens the car wasn't running to well, but he now has it turned around and is performing the way he needs it too.

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