Hi. I rebuilt my small block chevy and installed it back into the car. It ran fine for 200 miles. No issues. But the other day it suddenly started smoking real bad. And I mean A LOT of smoke. It does NOT smoke when cold. It only smokes after having been idling for a few minutes. Reving or fast idling the engine does not change the volume of smoke. No noises or other issues with the car (a '77 Camaro). In fact, it starts and runs great except for this.
Here’s what I’ve tried so far:
!. Disconnected the trans vacuum modulator line. No change.
Disconnected the PCV and oil breather. No change.
Tested engine compression. All cylinders are 125-140. All sparks plugs except #3 had fresh oil on them.
Tested cylinder leakdown. All cylinders 7%-14%
Checked for vacuum at the dipstick tube (to check for leaking intake). No vacuum. Intake gasket presumed good.
Replaced valve stem seals. This was something I knew had to be done because I had installed the wrong type during the rebuild. Most of the seals I replaced were in various stages of disinigration. Unfortunately, this did not solve my smoking issue (although it might have reduced the smoke a little)
So that’s where I’m at. I’m about to pull and disassemble the engine but I want to explore all other possibilities first. Much of what I’ve read on the internet suggests it could be a break-in issue, that it needs to be driven more. Could that be the issue even though it did not smoke for the first 200 miles of the break-in period? Any other ideas?