My '56 Corvette (265ci V8) was stored in the CA desert for about 39 years, inside a garage mind you, NOT outside. The original engine was rebuilt and had only about 2,000 miles on the rebuild when the car was parked. It did not take much to get the engine running and after a few months I have now gone through everything and it's running better than ever.
BUT, not all of the upper piston rings appear to be sealing yet. I am getting some blowby when running (smoke coming out of breather tube) and I can hear out the exhaust that it's the passenger side. I haven't done a compression check yet, I kind of don't want to know lol.
I first tried Redline with Auto-Rx for about 700-800 miles. After no change and having to replace the oil after a rear main seal leak, I have added some MMO to the crank case and gas tank. I'm still running Redline as it has the right amount of zync & phos for a flat tappet cam.
Anyway, I have just gone through a full tank of gas with the MMO in the crank case and gas tank. It seems to be helping a little bit but not enough. I'm going to be pulling my intake in a week and I was going to pull the spark plugs and fill the combustion chambers with MMO and let sit for a week. Then crank the engine with no plugs to blow out the left over MMO and fire it back up with the new intake and carb installed.
Do you guys have any other tips for me you can think of?