Before working on the electrical system, I decided to check the compression of the engine with a leak down tester.
Context: a ’51 era 216. Parked running (according to my Dad) in ’69 and never run again. Last June, filled all cylinders with Marvel after draining all the oil.
Last week: pulled all the plugs and turned the engine by hand. Turned over easy with no sticking.
Leak down test:
front cylinder – 100 PSI in = 64 – 72 PSI on the cylinder side (depending on where I held the engine by hand). Good sign for the rings, the air pressure itself forced the engine to roll over after TDC.
2nd cylinder – 100 PSI in = 16 PSI on the cylinder side. We had the same thing on the next 3 cylinders.
What the heck?
Went back to the 1st cylinder to verify the gauges and couldn’t get the results we had at the beginning. Couldn’t get the leak down to go above 20 PSI. [Insert bad words here]
Borrowed a compression set: throttle wide open – no compression on any of the 6 cylinders.
Next steps?:
1. Verify valves are not being held open by the rockers
2. Remove the head and inspect.
I am looking to those with more experience here for more ideas before I remove the head. What are your thoughts?
Thanks,
