[Jonsey]

Hi,

Had my engine rebuilt by a local builder a few years back after it threw a rod bearing. Engine is a 455 block, new rotating assembly from Butler. Changed the cam to a smaller XR288HR 288/294, 236/242,.520/.540, 110 for a more streetable setup. Heads are 87cc Edlebrocks from the late 90's.

I say a few years back, but looking at the receipts, it was 2013. After the engine was rebuilt, it sat on a stand for a few years while I restored the car. Finally got it back in the car. Engine has less than 300 miles on it, has never run right. Low idle vacuum, poor power, started popping through the exhaust on acceleration. I had an EZ EFI on it, and at first chalked up to my lack of knowledge on tuning.

Finally decided it wasn't the EFI and did a compression test. No compression on cylinders 2 and 4. Check the adjustment on the valves, still nothing. When installing the throttle body several years back, I had dropped a nut down the throttle and it had fallen through an open intake valve into a cylinder. I had to pull the head to get it. I was thinking maybe I had reinstalled the head incorrectly (I didn't respray the block with the copper spray) and that caused a head gasket leak now, which would explain the lack of compression and #2 and #4. Pulled the head. Maybe I don't know what I'm looking for, but the head gasket looks fine.

Pictures of attached. Clearly no combustion in cylinders 2 and 4. There's a pit in the top of cylinder 4 between 4 & 6. Doesn't appear to go through the deck.

I'm tired of learning at the school of hard knocks, would appreciate some wisdom. What else could cause the lack of compression on 2 & 4? Can you see a leak in the head gasket? Is that pit in the top of the cylinder a show stopper?

Thanks for your advice!