How do you start a engine that's not in a car?

Answer 1

Not that simple an answer, as it depends on how complex the engine is. In the simplest form (old engine w/carb, no computer controls), it can be as simple as:

1. have engine securely bolted into an engine stand or test strand, as when it tries to start it will rock all over the place.

2. hook coolant to the engine thru a radiator.

3. hook some sort of exhaust system to engine, as most engines NEED backpressure to work correctly.

4. assuming it is carb and not fuel injection, hook up a gravity feed gas line from a temp gas connection to either the fuel pump or the carb directly (as carbs do not need a lot of fuel pressure. Fuel Injected engines need much more fuel pressure to work.)

4. hook battery to coil, so the 12 volts of a battery can be increased to many thousands of volts as the electric field drops in the coil as the rotor in the distributor rotates.

5. wire a heavy duty wire from battery to starter....and then a temporary lightweight wire to the starter solenoid (a type of electric 'switch'.)

Note this is an inherently DANGEROUS thing to do...the gasoline could spill or ignire. The engine exhaust fumes are deadly if the engine is run inside or in a closed garage. The force of the engine could rock it off its stand. If not done carefully, once running it might be hard to stop the engine. The engine could over-rev and cause severe inside damage.

All in all...if you need to ask, you probably are NOT prepared with all the safety issues that need to be followed to do this without burning/asphixiating/crushing someone.