Test Starting an Unmounted Engine – Dave’s Garage

I hope your summer is going well… it is nice to finally get somewhat of a break from the rain. As I am sitting here typing this, I think I can actually hear the grass growing outside my window. I have been quite busy with my MG TF project, the body tub went back on the running chassis yesterday, now I am hooking everything back up and trying to find all the parts I took off last year…

This question came to me this month:

Q. I have the “sliver” of a ’25 Moon. Continental 6 motor, chassis, wheels, radiator, hood, steering wheel…umm that’s about it. I had the starter rebuilt & now want to try to see if the motor will run. The flywheel does turn & it doesn’t appear to be “stuck”. I think it’s a 6 volt system, but is it negative ground? The radiator leaks real good, too! What do I have to do to test it out? Is there a basic flow chart/ or some diagnostic chart to follow for basic engine starting? Thank you for your response.

A. To test an engine, the engine needs to be firmly mounted to something. I would recommend bolting it in to the frame. Before you attempt to start the engine, the carburetor should be taken apart and cleaned and the engine oil should be changed. You need some provision to check for oil pressure. Do you have the gauge from the car? If not, do you have a mechanical gauge? With the engine bolted down, the carburetor cleaned and the oil changed the spark plugs should be removed and the engine should be turned over using the starter until there is good and stable oil pressure. To run, the engine needs three things; air, fuel and spark. You can hook the distributor up to any coil, six, or twelve volt, positive or negative ground, the electrons do not care, and the point and condenser system will work with any combination of the above to test fire an engine. I would check the points to make sure they are clean and working first. Either wire a switch in to the wire, or hook it up in such a way to be able to quickly disconnect a wire to shut the engine down. With the carburetor cleaned you can take several feet of hose and either hook it up to the fuel pump (if it works) or si-phon fuel through the hose from a gas can to the carburetor, keeping the gas can higher than the carburetor. Since you are test firing an engine, and only running it momentarily, you can put the coolant hoses in to a five gallon pail of water. To start the engine, use jumper cables directly on the starter. The starter has permanent magnets in it so it is not polarity sensitive. Place one lead on a good ground, and the other on the starter terminal. When you have power going to the ignition coil and you are ready to start, connect the jumper cable to a battery to activate the starter. BE prepared to “pull the plug” and keep a good fire extinguisher near by! This will quickly tell you if the engine is running or not, but will not give you much information as to the condition of the engine. Since it has been sitting for so long, it will probably not run very well, and it will smoke. Taking compression readings and noting the oil pressure will give you a good idea of the condition of the engine. I would not run the engine for more than a few seconds. Best of luck to you and keep us posted with your results.

I received this tip from Ken Taplin, and I am passing it along. I do not have a cell phone or a GPS, but I know most people do. I have not tried this, but would assume that it will work since most electronics operate on low voltage DC power.

Dave, Maybe I’m the only one that didn’t know this but I recently discovered that you can run a gps and charge a cell phone just as well on 6V as 12V. I used to carry a 12V battery pack for that. You do need the right polarity and In my positive ground cars I have installed marine grade power points. The cases are plastic and therefore not grounded so you can hook up the two wires for the right polarity. – Ken Taplin Blue Hill, Me.

Please email all inquiries to: Dave
or snail mail
32 Turkey Hill Road
Richmond VT 05477

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