Building an Engine Run Stand.
In this article I’m going to talk about a run stand for engines. I will also show you how I built mine. Is it the best one out there? I doubt it. I built it 30 years ago and still use it. I won’t let a motor leave my shop without it being on it.
So what is a run stand? Well it’s a stand we can run a motor on before we ever put the motor in the car. This way we can tune the motor, timing, adjust valves, adjust carb(s), make sure the charging system is working, and check for leaks. The other nice thing here is we can “break the motor in” without having to put it in the car.
So what does it take to make one of these stands? There are a lot of ways to do it, but I will explain what I did. The first thing to do is get a parts list together. I started with an 002 bus bellhousing. Why? Well it has a flat back to it and was easy for me to bolt to a flat plate. The motor bolts to it and the starter pocket is already there. It’s an easy way to go. Now let’s build.
Let’s talk about what you want it to monitor. At minimum you should have oil pressure, oil temp, volt meter and a tachometer. I’m a gauge nut so mine has too many. With the gauges you will want two idiot lights. I use orange and red. You will want a push button switch that can handle some amps. I use two switches on mine. One on/off switch. This turns on the gauges. Why? Well if I have a motor that is bone stock and doesn’t have gauge sending units then I just leave that switch off. Then I have a switch that is off/on/on. So three positions. Again, why? Well the first pull up on that switch gives me the idiot lights and the gauges if that switch is on, but no ignition power. That way I can turn the motor over without it firing. Why would you want to do that? To get oil pressure. Once I have pressure, I put the switch all the way up and now I have ignition power. Push the starter button and fire it up.
Some other things we need to think about. We will need a 12 volt battery and a small gas tank. A one gallon tank is more than enough. Just get what’s cheap, it doesn’t need to be fancy, but I’m not a huge fan of the plastic gas can sitting next to the motor with a hose in it. It works but in my opinion it’s too easy to trip over or cause a hazard. I mounted the tank above the motor so there were no priming problems. Make sure you put an on/off valve on it. Also on the battery I have a main disconnect switch. If things go bad you can always cut all power with that. That’s about all the parts you need to gather before I would start.
Now let’s decide how we want to build this. I wanted my motor up so it was easy to work around and on wheels so I could wheel it outside. I also wanted an open front so I could use a jack and put the motor up on without having to pick it up by hand. I put flat plates on the upper rails so it would catch the heater boxes if I just wanted to set the motor on the stand without bolting it to the bell housing. On the back side I made an area for a voltage regulator and a battery.I made the gauge panel able to rotate so if I’m on the side of the motor I can still watch the gauges easily. I also put a system one filter on the stand so I can check the filter after running it.
For the wiring I used an old harness from a bug and cut out what I needed. This way the color codes match what is (or should be) on the car. Just as a reminder: Red is hot all the time, black is hot with the switch on, and brown is ground.
Here is what I did:
Red (10 gauge) Regulator to D+ on Genertor or B+ to battery if an alternator
Light blue (14 gauge) Regulator to DF on Generator or (push on) on alternator to idiot light.
Black (12 gauge) from ignition power side of switch to the positive side of coil (15)
Green (12 gauge) from tach to negative side of coil (1)
Blue with yellow strip (14 gauge) from idiot light to oil pressure sender (gauge sender is marked (WK) if it is stock sender then the push on
Dark blue (12) gauge from the oil pressure gauge to the (G) on a gauge sender.
Yellow (12 gauge) from oil temp gauge to oil temp sender.
That’s it for the motor to that gauge and switch panel The rest is up to you. The only tricks I use here is on the oil pressure wire (blue with a yellow strip) I use a push on spade connector. That way it slides right onto the stock sender. Now when I use a gauge sender I have a terminal that slides into my push on and converts it to and eye style end. That way I am not cutting wires all the time. The other trick here is I make some connectors that will bypass the voltage regulator when I am running an alternator. The rest of the wiring is up to you.
Remember that hardest part about wiring is getting the smoke back in the wire. It’s not a bad idea to put a 30 amp fuse in the main line from the battery. If you are doing more than one motor this is a great tool to have. Mine has lasted 30 years now and I have to say we use it at least once a week. Here are some pictures of the old gal, be gentle she is showing signs of a lot of use.