My friend has a 455 in his Camaro. He and his wife got serperated and she pushed his car outside. The air cleaner and hood weren't on the car and rain when down the carb. 4 cylinders don't have compression now. What is the worst thing that could have happened to it. Do you think it needs a complete tear down / rebuild. He started the car once and it shut off. It had 87 octane in it and it barely runs on pump gas. We thought that was the problem till somebody did the compression test on it. I know it is hard to analyze something like this. I am just trying to get an idea of what has happened to it. Thanks

He should have cranked it with no plugs in it. I bet now, he has bent conrods, a blown head gasket, or a healthy combination of both. If it's not compressing, I'd say its ruined and needs rebuilt.

water down carb + crank motor = hydrolocked cylinders (aka complete fubar)

water is not compressible so when you insist on it by cranking the engine something else has to give - like one of the thinkgs listed above.

Wow! I would have never though about the water sitting in it and where it would go. Thanks guys.

could have some valves stuck open just slightly too.

I pulled the engine tonight and brought it home. I plan the pull the valve covers and see what I can see. I'm not exactly sure how long it was outside and how much water really got in it. I really hope, for my friends sake, it's not garbage. It's a really nice engine and he is going through some tough times right now. Just one more thing to bring him down.

It won't hurt to put some oil in the cylinders in case of rust will it?