Engine rotation

engines
starters
#1

Can the wrong starter cause an engine to run in the other direction causing the water pump and other accesories to run in the wrong direction.

#2

Engine will not run that way. If it did, it would suck air in from the exhaust, but with no fuel, and blow it out the air filter.

#3

It may be possible to turn an engine the wrong direction but it won’t fire up.

And you can’t reverse the electrical connections on a starter because it is chassis-grounded.

#4

You’re right that you cannot wire a starter backwards, but you can wire a battery backwards if you try.

I don’t think that any starter that I have ever looked at would engage the flywheel if it spun backwards.

#5

I’ve seen some mechanics do some wondrously awful things! If it’s impossible, one will manage to do it.

#6

No. An engine will not run in the wrong direction. It can be turned the wrong way, but it won’t start or run.

#7

The wrong starter wouldn’t do it. The wrong starter could turn the engine backwards but it wouldn’t run.

For the engine to run backwards the camshaft would have to be changed for one that operated the valves at the corrected time.

They used to do this occasionally on the NASCAR circuit. Done first by none other than Smokey Yunick.

#8

There was a small 2 cycle outboard boat motor that could be run in either direction. I believe that it was a Neptune made by Muncie Gear Works. It could be started in one direction to manuever away from the dock, then stopped. One would fit the rope around the flywheel notch that would allow starting the motor to run in the opposite direction. However, this wouldn’t be possible with a 4 cycle engine with a camshaft that operates the valves.

I once purchased a 1948 Dodge where the battery had been connected backwards. This Dodge was a 6 volt positive ground. The son of the previous owner didn’t realize that some cars were positive ground. I caught it when I noticed that the ammeter gauge read discharge when the car was running. When I turned off the car and turned on the lights, the ammeter moved to charge. Everything seemed to work except the radio. I discharged the battery and recharged it and repolarized the generator and all was well. The starter turned the engine in the correct direction when the battery cables were reversed.