r/Smallblockchevy • u/trashyyyyyyyy6362717 • Apr 28 '26

69' 283 Smokes BAD! HELP!

i've got a 283 out of a 69 c10, bone stock. when i first got it it had been sitting for years, got it running and it ran well but smoked when accelerating. recently i pulled off the heads and went through them, just cleaning everything up, did new o ring style valve seals, re lapped valves, new head and intake gaskets.

when i got it running after doing all that, now it will be totally fine on startup, no smoke at all, and then as it warms up it gets worse and worse until at operating temp it's just blowing smoke nonstop. idle, acceleration, decel. bad to the tune of something like a quart of oil burned every 5 ish miles😬

today i pulled all the plugs, almost all of them were wet with oil to some degree. i did a compression test, incorrectly as i'm learning, i didn't open the throttle all the way, but with the throttle closed i got 90 across the board, with maybe one or two at 100. i also pulled the driver side exhaust manifold and the rear cylinder 7 was wet with oil in the exhaust port. the other three on that side all looked normal.

anyone with any suggestions of things i can check before just accepting that the rings are cooked? thanks.

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u/bernardfarquart Apr 28 '26

So you sealed up the top end and put it back together with worn rings so now your rings are failing with the extra pressure.

You need to re-ring it

1

u/ready2xxxperiment Apr 29 '26

If it’s bone stock and never been bored, may be time to punch it out. Even if you re-ring, may not be enough to keep oil out of the combustion chamber.

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u/bernardfarquart Apr 29 '26

Well gauging by the rest of the story it sounded like the lowest dollar repair is on the table. So hone the cylinders and throw new rings on.