|The MGA With An Attitude
DORMANT ENGINE TECH -- DE-101b -- Page 2
For a car that has been sitting for more than a year, the first order of business is to get rid of the stale fuel. It will most likely not run at all on fuel more than a few years old, not even a pop. Drain the fuel tank completely and put in at least two gallons of fresh fuel. This would be a good time to change the fuel filter if the car has one. Open the fuel line near the carburetor(s), and flush through until you get fresh fuel coming out. If the car has an electric fuel pump (and it works) this is a cinch. This is also a good time to check the electric pump to be sure it works. Otherwise you may use a hand vacuum pump to draw the fuel through the line. If the car has a mechanical fuel pump mounted on the engine, it would be a good idea to remove the pump and operate it by hand to verify that it actually works. This could be another way of flushing the fuel line from the tank to the engine.
Depending on the type of carburetor(s), it could be convenient to remove the top of the float chamber and remove the stale fuel inside, and maybe clean the inside of the float chamber. Old evaporated fuel can leave behind an inert liquid similar to urine, or even something quite viscus like honey, or even a solid substance that looks like dried airplane glue. Wash this stuff out with a little gasoline, be sure the small hole exiting the float chamber towards the main fuel jet is clear, and be sure that the float valve is free to move by gravity alone. Reassemble the fuel system and fill it up with fuel. Verify that the lines and hoses will hold the fuel pressure without leaking, and _especially_ that the float valve stops the fuel flow when the float chamber is full.
If the stuff on the dipstick looks like anything other than reasonably clean engine oil, it would be a good idea to change the oil and filter before running the engine. When you're ready to turn the engine over, just remove all the spark plugs, give it a little cylinder oil and give it a crank.
It would be beneficial to the engine bearings if you could prime the oil system before cranking it. You can NOT do it this way with an MG, but with some engines (V8's in particular) you can remove the distributor and spin the oil pump with a socket drive extension in an electric drill. With my MGA engine I remove the flex line from the engine to the oil pressure gauge and pump in a pint or two of oil with a finger pump oil can. I keep pumping until I can feel a noticeable resistance to flow, meaning that I am then forcing the oil through the bearing journals. Any engine should have a port for an oil pressure gauge line or an oil pressure switch or transducer. Remove this fitting and use the port to inject oil into the engine before cranking it. Reinstall the fitting of course. This should (may) also effectively prime the oil pump.
To check to see if the engine is seized, put the transmission in high gear (assuming stick shift) and rock the car fore and aft by hand. Backlash in the gear train will allow it to roll a few inches either way so you can put in a little inertia. Give it a good bump each way a few times and see it engine will rotate a bit. If it does turn, just get on the starter and crank it (without the spark plugs) to get the oil pressure up. The pressure should come up on the gauge (or idiot light go out) within a half minute or so, but it could take as much as a full minute of cranking the first time.
If the pressure doesn't come up while cranking, don't worry too much, it doesn't always work. Next step (if the pressure doesn't come up) is to prime the oil system again just for good measure, (shouldn't take much the second time around). Then put the spark plugs back in and try to start it normally. If it starts the oil pressure should come up within 10 seconds of running, otherwise you really have a problem. Don't run it more that 30 seconds without oil pressure. So long as there's an oil film in the bearings you're okay with idling, but with no oil pressure there's no oil flow, and the oil film will soon overheat and break down with damage to the bearings.
If the engine is seized, the problem will most likely be that the pistons are tight in the cylinders. There are a couple of possibilities, but one could be that the rings are rusted to the cylinder wall in one or more cylinders. When an engine is stopped there is always at least one intake valve and one exhaust valve open, and these cylinders can breath with changes in temperature and barometric pressure. Over a long time some humid air can get in and allow rust in the cylinders. If the car was stored indoors with the spark plugs in place, there's a good chance that the engine is not seized.
Another reason for an engine to be seized is if someone put a little oil in each cylinder and then let it sit for years to dry out, especially if the spark plugs holes were left open. When the oil dries out it leaves a varnish deposit that looks a lot like dried tree sap or tan phenolic plastic without the fiber filler. I recently retrieved an engine that had been oiled and then left to sit in a barn with the head off for several years. I had to beat the pistons out of that one with a heavy hammer.
If it is seized, try a big wrench on the front end of the crankshaft. You could apply as much as 200 lb-ft of torque if necessary without damaging the front pulley retainer nut. Otherwise you could remove the starter motor and try using a big pry bar against the ring gear to get it to break loose. You can apply a lot of leverage at that distance from the center of rotation, just don't break the transmission housing or the teeth on the ring gear. The rear plate on the engine is usually steel and will hold up to a lot of abuse.
If it breaks loose and turns so that the starter will turn it over, it was probably the rings rusted a bit to the cylinder walls. In this case, go ahead and crank it over on the starter to blow any fluid out of the cylinders through the spark plug holes, put one squirt of oil in each cylinder, install the spark plugs and start it up. Expect a huge cloud of white smoke out the exhaust for a few minutes until it clears out the cylinders. Once you get it up to running temperature, shut it off and give it an oil change and a fresh oil filter.
If it turns with the wrench but is so tight that the starter doesn't have enough power to spin it over, then it's probably fouled with varnish on the sides of the pistons. In this case you would likely be in for an engine tear down to clean the pistons, hone the cylinders and install new rings. Since you don't have much to lose here, it might be worth a little tinkering first. Put some solvent in the cylinders for a few days, then try towing it in top gear to see if you can get the engine to spin over and loosen up enough so the starter can turn it. If you do get it to run this way, you may expect the rings to be seized and the engine may burn a lot of oil. Apply solvent liberally in the cylinders and let it sit for a week, then try it again. Drive it for a while, at least a few hundred miles, and see if the oil consumption goes down. If not, it will need new rings anyway.
If the engine is seized completely so you can't get it to turn at all, put a few ounces of solvent in each cylinder and let it sit for a while, like a few days to a week. Most any mineral based solvent will do, diesel fuel, mineral spirits, kerosene, paint thinner, WD40, Liquid Wrench, etc. Gasoline, alcohol, lacquer thinner, or acetone are not so good for this because they evaporate too quickly. Engine oil is also not a good candidate for this because it's a lubricator and not a very good solvent. If you can get the engine to break loose and turn after this soaking, you may get away without having to tear down the engine.
If it's still seized after all this, it will have to come out for disassembly. Remove the cylinder head, flywheel, oil pan, all the main bearing and connecting rod caps, and remove the crankshaft. Then fashion a block of wood that just fits in the cylinder bore on top of the pistons and have at it with a five pound hammer to break the pistons loose from the cylinder walls. Do not push the piston down so far that the bottom ring drops out the bottom of the bore, or you may have a devil of a time getting it to go back up. If there is a noticeable ridge at the top of the cylinder, you should use a ridge reamer to cut it back flush with the worn part of the cylinder before pushing the pistons out the top of the bore. If the piston rings are seized and you force them up past a substantial ridge at the top of the cylinder, you may damage the ring grooves in the piston.
Just in case you didn't know, all split bearing housings are bored in assembly, so the split line is never exactly on the center line of the bore. For this reason you must keep the bearing caps in order and mate them back in the original position in order to retain the correct bore size. If you were to mix up the connecting rod bearing caps, the engine would probably be seized in some of the bearings when you reassemble it.
Let me know how you make out with this project. It's always nice to get an engine running without having to tear it apart.