The Stovebolt Site Forums The Shop Area Engine Shop what would it take to test run an engine

I may have found another 235 that the owner says runs good. I would like to run it, what do I need to run it. If I took a gallon container for fuel, a battery of the correct variety, 6 or 12v. Could I secure the bellhousing to a large block of wood and do the same for the front engine mount, could I safely test run it without any coolant? Dave

I would hook a garden hose up for coolant, just let it run through it and out on the ground. Use the heater hose inlet and block the water pump inlet hose. The engine will set dead solid with out heavy blocks of wood. Just set it in a old tire or bolt some support legs to it. With out a driveline hooked up, there is no torque being applied, so you won't have any twisting or spinning trying to happen.

Joe

Sounds like a great idea, I'll have to look at rigging up an oil pressure guage which should be fairly easy. No spinning fan or generator either, that would be slick. Thanks. Dave

I strap an engine down to a heavy hardwood forklift pallet with a couple of ratcheting cargo straps, and at least block off the coolant ports and fill the engine with water. If a garden hose is available, adapt it to the water pump inlet, and don't run the pump with a belt- - - -you can control coolant flow with the hose faucet. Remove the thermostat, and let the coolant just run out of the top fitting. If you goose the throttle, there will be enough torque reaction generated to try to turn the engine over, so don't get rowdy on the gas.
Jerry

Edit: Up there in Homer, don't forget to drain the water back out after your test run- - - - -enough water can remain standing in the block to freeze and burst the casting next time it gets cold!
Jerry

Pallet is a great idea, I'll have to bring one with me, if I buy the engine I can haul it home on the pallet after testing. The water in the engine is the reason I'm doing this in the first place, the 216 block was cracked real bad. Thanks for the good ideas. Dave

You need some sort of exhaust system. The noise will be so loud you couldn't hear enough to tell anything about it. You can run it about 30 seconds without water in it. Those old castings were thick. If you run it on 12 volts you will need a resistor in the coil circuit.

Would doing a compression test without running it be worth while? That would be much simpler but not all telling. Dave

A compression test won't find vacuum leaks, noisy lifters, etc. It definitely won't indicate low oil pressure or a rod or main bearing knock. Run it if at all possible.
Jerry

Compression test is the place to start when looking at an unknown engine.
THEN
a test run ideally on a dyno at varying load. I am sure you have full dyno in your back pocket just like the rest of us.

Oh yes make sure the engine cannot roll over if you test run it. All rotating machines can roll over if not clamped to something.

Dan Bentler

homer52 writes, "...235 that the owner says runs good. I would like to run it...."

A bit of philosophy for you. Never install an engine in your vehicle without rebuilding first. This is the only way you will have reliability and peace of mind. An exception is an engine rebuilt by a well known and reputable rebuilder.

You buy a used engine, you also buy whatever problems come with this engine. Often you buy a person's headache. A seller is out to get rid of his engine and out to get your money. There is little motivation for a seller to be truthful.

Your wanting to test run this engine indicates you are wary. You should be. You work hard for your money, sure don't want another taking your money and giving you a raw deal.

Engine sitting on a shop floor, there is only one test you need, "Will the engine turn over freely and easily?" Take along a sparkplug socket, a ratchet, a breaker bar and a socket to fit a flywheel bolt. Bring a flywheel bolt and washers in case the flywheel is gone. Pull the plugs, crank that puppy over by hand a dozen times. Should spin very easily, should blow air out the plug holes, in firing order sequence, no oddball noises.

A caution is to ask if the engine has been rebuilt previously. Want to be careful not to buy an engine which is bored to the max and journals turned to the max, 0.060 and 0.030 for a good maximum guideline, cylinders and journals, respectively.

Passes your test, bicker over the price keeping in mind you will fully rebuild this engine. Once rebuilt, you know exactly what you have; a fresh reliable engine.

Do it once, do it right, there is no substitute for peace of mind while driving your old classic truck.

Billyray

I would be concerned trying to run an engine with out some kind of solid stand. it's not that hard to build a stand to supppout an engine like the one in question. There is still a lot of torque to control. Secure the stand down and then run without some one getting hurt.