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How can I know the condition of a core engine after removing the spark plugs?
What should be the condition of the spark plugs after many years of not running the engine? After removing them what should I look for to know the condition of a core engine I am about to buy?
Last edited by Bassemaa93; Aug 18, 2019 at 01:24 PM.
Hopefully you won’t find them caked with rust. If the engine was stored with any care, hopefully the plugs are dripping with CLEAN engine oil, all the rocker arms have been loosened, oily rags stuffed into the exhaust ports/manifolds, carb taped and bagged to keep dirt and debris out, hoses/fittings taped closed, etc. if someone went thru the time and effort to preserve the engine, chances are it was in good shape when pulled. If not, a tear down is the only sure bet that what you have is a good core.
I have bought many “ran when pulled” engines over the years, unless it was a recently pulled engine, they almost always had rust in the cylinders. They usually end up stored in a corner of a barn, with a rotten tarp over it, with 20 years of dust piled on. Whatever cylinder had open valves would be full of water, sometimes the oil pan would be full of water. The carburetor (if it’s still there) would almost always be rusted solid,
Are they a matched set? Are they the correct plugs? This isn't critical but could indicate a lower standard of maintenance or changing individual plugs due to oil fouling.
Look at the threads on the plugs and the head. Are any stripped?
Look at the porcelain, Are they covered with oil, either fresh or burned on?
Are the electrodes rusted? This indicates water in the cylinders. There will be rust on the exterior of the plug/hex area, it's mostly meaningless.
Are any of the porcelains excessively clean as if they were being steam cleaned due water getting in the cylinders?
Is there any material spattered on them from a piston from pre-ignition/pinging?
Good luck!!!
Last edited by Sugar Bear; Aug 19, 2019 at 05:17 AM.
Anymore, buyers can't be too choosy when looking at a used Oldsmobile engine. Especially if it's a BBO or earlier SBO. The 307s are still plentiful but unless you're redoing a G body Cutlass, who wants one of those?
If the crank turns with a wrench you should buy it. Then when you get it home you can do a cylinder leak down test to determine the health of the engine..
