Diesel Running Backwards

[Bentrim]

Years ago had a JD 70D that was trying to move at too low an engine speed and just as it died pulled the clutch the engine kept running --- Interesting as the oil bath air cleaner was now blowing oil out the grille.

 

[kwbobwi]

I had it happen to the 3406B Cat engine in my Freightliner.
It'll get your attention Inca hurt when black smoke comes out the intake

 

[RickB]

One of the more significant updates to Deere 720 and 820 diesels around 1957 when the "black dash" tractors came out was a different camshaft profile that all but eliminated the unwanted habit they had of running backwards when lugged to a near stall.

 

[DSteiner]

So I discovered something I was unaware of and just wondered if this was common knowledge. When using my logging winch, and bogging it down to the point of almost stalling, the engine would start running very oddly. After shutting it down I noticed the cable was unwound and tangled inside the winch. This happened twice before I discovered why. Apparently the engine under stalling conditions can start to run backwards, taking air in from from the exhaust and exhausting through the air intake, not a good condition for the engine. And in the process running my winch backwards and tangling up the cable. Anyway, now I'm more careful about how I run it with the winch. So is this common knowledge that I somehow previously just missed?

My 1320 will also run in reverse for maybe 30 seconds.

 

[Tony H]

So I discovered something I was unaware of and just wondered if this was common knowledge. When using my logging winch, and bogging it down to the point of almost stalling, the engine would start running very oddly. After shutting it down I noticed the cable was unwound and tangled inside the winch. This happened twice before I discovered why. Apparently the engine under stalling conditions can start to run backwards, taking air in from from the exhaust and exhausting through the air intake, not a good condition for the engine. And in the process running my winch backwards and tangling up the cable. Anyway, now I'm more careful about how I run it with the winch. So is this common knowledge that I somehow previously just missed?

Single cylinder model airplane engines would do that all the time. The ones you turn over by hand.

 

[Diwali]

Never happened to me with anything on wheels but my 2 stroke chainsaw would run backwards on starting and you don’t really notice until you try cutting.... that’s when it got a little dangerous!

 

[Grumpycat]

So I discovered something I was unaware of and just wondered if this was common knowledge. When using my logging winch, and bogging it down to the point of almost stalling, the engine would start running very oddly. After shutting it down I noticed the cable was unwound and tangled inside the winch. This happened twice before I discovered why. Apparently the engine under stalling conditions can start to run backwards, taking air in from from the exhaust and exhausting through the air intake, not a good condition for the engine. And in the process running my winch backwards and tangling up the cable. Anyway, now I'm more careful about how I run it with the winch. So is this common knowledge that I somehow previously just missed?

I remember recently seeing a classic tractor TV show where an old single cylinder diesel tractor was designed to be stall-bumped into running the other way for reverse.

 

[Rgladden]

So I discovered something I was unaware of and just wondered if this was common knowledge. When using my logging winch, and bogging it down to the point of almost stalling, the engine would start running very oddly. After shutting it down I noticed the cable was unwound and tangled inside the winch. This happened twice before I discovered why. Apparently the engine under stalling conditions can start to run backwards, taking air in from from the exhaust and exhausting through the air intake, not a good condition for the engine. And in the process running my winch backwards and tangling up the cable. Anyway, now I'm more careful about how I run it with the winch. So is this common knowledge that I somehow previously just missed?

Detroit Engine??? Detroit's are designed to be able to run in either direction and can under some circumstance do so.

 

[Rgladden]

To save money I’ll let my tractor engine run backwards for 8 hours as it pulls CO2 out of the air through the exhaust stack and refills the tank with diesel by the end of the day! It can’t be bad for the tractor cause the hour meter says it’s getting newer and newer!
….say, anybody want to buy a bridge?

Good luck on that!

 

[Rgladden]

As a young man I raced motocross professionally. We had large crowds at pro events. I provided some excellent entertainment one day when I fell in alarge mudpuddle. People were getting a good laugh about me covered with mud!. I started my bike up and dumped the clutch to find out it started backwards. My bike pushed me back through the mud and I crashed again totally inundated in the mud.
The fans were all laughing hysterically.

I've never had it happen on a diesel but on that 2-stroke bike it ran perfectly!

Why shouldn't it run just fine? all that is required that the piston go up and down.

 

[Rgladden]

Had an incident on a job site where a fellow accidently backed over a pick up tuck with a 500 ton rock truck and tried to blame it on the engine starting backwards. Didn't fly very well when he learned the engine only drove a generator and each wheel had its own DC drive motor

 

[RickB]

Why shouldn't it run just fine? all that is required that the piston go up and down.

Lube oil pumps don't supply oil to the engine when the gears or gerotor is turning backwards. Mufflers make poor air filters and air filters make poor mufflers.

 

[rangerrzr]

Harley Davidson made Golf Carts (True Story). They were 2 Stroke, and they had reverse. The Reverse was used by stopping the engine and the starter ran backwards running the engine backwards.

 

[RickB]

The recurring theme on individual engines designed to run in either rotation is their two stroke design. No lube pump.

 

[BravoXray]

DD engines were not designed to run in either direction. Unique designs allowed each engine to run in the required rotation for specific applications.

Maybe I wasn't clear about what I meant.
Each engine was built to run either clockwise or counter-clockwise, but not in both directions. The blocks had a cam galley on both sides of the block so the cam and balance shaft could be on either side. That way the cylinder head could be mounted with the exhaust on which ever side suited the application. Same for the blower, depending on which way the block was installed, the blower mounting pad could be on either side. The block also had provisions on both ends of the block for the crankshaft thrust bearings, so the cranks could be installed either direction. If you were building an engine from parts, you had to be sure you had all the correct parts for that configuration, like proper oil pump and camshaft.
Early engines had blowers that ran at 1.69 times crank speed. Later ones used smaller rotors and ran at 2 times crank speed.

 

[jimgusek]

So I discovered something I was unaware of and just wondered if this was common knowledge. When using my logging winch, and bogging it down to the point of almost stalling, the engine would start running very oddly. After shutting it down I noticed the cable was unwound and tangled inside the winch. This happened twice before I discovered why. Apparently the engine under stalling conditions can start to run backwards, taking air in from from the exhaust and exhausting through the air intake, not a good condition for the engine. And in the process running my winch backwards and tangling up the cable. Anyway, now I'm more careful about how I run it with the winch. So is this common knowledge that I somehow previously just missed?

It sounds like you have an old style Jimmy two stroke, they would run very well backwards. When this happened many had oil bath air filtering and would suck the oil in. Literally the engine under stall conditions would roll backwards and start.

 

[Fuddy1952]

Check THIS out!

 

[Grumpycat]

Lube oil pumps don't supply oil to the engine when the gears or gerotor is turning backwards. Mufflers make poor air filters and air filters make poor mufflers.

When an engine runs backwards the air still moves through it in the same direction, in the air filter and out the exhaust.

 

[RickB]

When an engine runs backwards the air still moves through it in the same direction, in the air filter and out the exhaust.

I guess you've never actually seen a 4 stroke diesel run backwards.

 

[pmsmechanic]

I guess you've never actually seen a 4 stroke diesel run backwards.

Or a two stroke Detroit.