Engine knock

[427TJ]

Thanks Eric! Oil pressure is good: 40-ish at idle, as high as 60 at anything above. It's definately a combustion knock. I've heard bad bearings and piston slap before and I don't think that's it--even though the old Rat has a ton of miles on it. It's not a steady knock, it's more occasional and not with any real rhythm.

[Chevy454]

A cam going away will make some funky noises deep down...been there, done that, and almost ruined a 427 because of it.

[Xplantdad]

Bill...sounds like time to do some compression testing maybe? Have you changed your oil and checked it? My engine had a weird knock, too...and you know what happened after that!

Check the basics stuff and rule them out first...?

[427TJ]

Yeah Bruce, I'll do a compression test but I have a feeling all it will show is that a bad case of old motor has set in... After doing some research I'm 99% certain it's a combustion knock from carbon buildup in the chamber. The old plugs have oil buildup from leaky valve guides and I think there's got to be carbon buildup in the chamber. I think I'll nurse it through the summer (the Pac-Northwest All-Chevy Show is coming up and I already paid the admission) and then pull the old dog out and get it rebuilt.

Thanks guys for the inputs!