how to make engine run outside of car?

[lifeiskaos]

as the title states, what is required to test an engine before putting it in the car? obviously you need a battery, and gas. i imagine it wouldnt be very hard to make a fuel cell with a stock fuel pump. mainly curious about wiring. what to do with the main harness connector, and if block itself (or engine stand?) is sufficient for the main ground. assume its an m50, although it should be the same for m50/m52/s50/s52. thanks

[bwh13]

The test stand should be enough of a ground as long as the battery is attached to it. Fuel and spark and coolant, if you want to run it for more than a minute or two...that's all you need.

[gregslow318i]

how are you going to use a starter? you need a trany also? my buddy once started a sbc buy sitting on it and pouring gas in to the carb was hella funny

[88E30M50]

The test stand should be enough of a ground as long as the battery is attached to it. Fuel and spark and coolant, if you want to run it for more than a minute or two...that's all you need.

Would an engine stand be strong enough to keep the torque from tipping the engine when it fires? Most engine stands I've seen are pretty stable for overhaul work, but would not be the best choice for a running engine.

[Jean]

You'll probably want to build something custom with enough weight to hold it all in place. search google, I've seen someone do this for an ls1/2 ....

[Farbin Kaiber]

Yeah, most engine dyno shops have the setup you require. The crazy glowing BMW header pic came from a stand like this.

[kronus]

Stupid question - you don't need the ECU and harness to control stuff in order for the engine to start?

Actually, now that I'm thinking about it, m20 ignition is fixed timing, because it uses a distributor. The incoming air is controlled by the throttle body... so the only thing the ECU adjusts is the fuel delivery?

[matt]

The distributor only decides which cylinder is firing, it doesn't decide the ignition timing. The ECU does that.

Running a motor out of a car, on any sort of stand not designed for the purpose, is a really bad idea.

[kronus]

Ah, I see now. Ignition timing is adjustable within the window where the rotor and cap are in contact.

[hoveringuy]

Running a motor out of a car, on any sort of stand not designed for the purpose, is a really bad idea.

Yep, that's exactly what I'll be doing (hence the M54 foolishness thread title.)

I have too many variables going on to feel comfortable just putting the motor in the car... I really wish I had a spare chassis just to hold the motor and give it life support while I get it running.

I think a $300 e30 shell with a working fuel tank and battery would make a heck of a test stand.

In the absence of that, I'll build a cradle with wheels to roll it outside. Fuel pump in a 5gallon bucket with lid. Battery on the stand.

It frightens me already.

[devonjordan]

Yep, that's exactly what I'll be doing (hence the M54 foolishness thread title.)

I have too many variables going on to feel comfortable just putting the motor in the car... I really wish I had a spare chassis just to hold the motor and give it life support while I get it running.

I think a $300 e30 shell with a working fuel tank and battery would make a heck of a test stand.

In the absence of that, I'll build a cradle with wheels to roll it outside. Fuel pump in a 5gallon bucket with lid. Battery on the stand.

It frightens me already.

Wow, good luck with that. Be sure to post the vid of the ensuing disaster, haha.

[matt]

Strange, I just gave away a $300 e30 with a fuel tank and no motor. Didnt have any takers for the longest time at $300, so I sold it to a scrapper for $100.

[lifeiskaos]

thanks for the help guys. so it can theoretically be done without having to plug in any of the wires on the main harness plug to the chassis?

[matt]

No, it can't be done WITHOUT all that stuff.

[Adrian_Visser]

why go through all this trouble?