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Taking the engine apart the second time is much easier than the first! I actually know what I'm doing and everything is nice and clean from the first time.





This is #4, my cylinder that is basically dead. The exhaust valve has barely been sealing at all. After pulling the head I can tell exactly which cylinders have better compression by how clean they are.





The bottom of #4 exhaust valve looks basically like the top! That is, it's being as exposed to the combustion! I suspect it wouldn't take too long, running like this, to wear out a valve guide and stem. I don't think these valves get great lubrication at the best of times.





If the shop has time to machine the head, and grind the valves for me next week, I'll be able to get the car back together next week as well!

The Cavalier is going to be purring like a kitten!

Why do you want to machine the head? My understanding is that there isn't much that can be taken off these heads before it starts getting too close to the valves. If there isn't a problem with the head, it may be best to just leave it as is. I don't think your compression problem was due to a head/gasket problem. It looks like all valve seats/faces to me.

I agree with Kevin.
You need to be very careful about machining the head. It's not like the head for an overhead valve engine that is very rigid and what might appear to be warpage will be easily taken care of when the head is torqued down.

Good thoughts! Machining the head was a recommendation from my engine builder. (This is not his first Packard.) Not to help with the compression issue, but to prevent any head gasket leaks.

I'll get him to check it first and get him some measurements before he does anything.

I took my head to my engine builder this morning and mentioned the concern about there not being much clearance. He thinks the head has the factory machine marks on it, so unless he has to take lots we'll be okay. I'll double check it before I torque it down.

Exhaust seats will be 30/45/60 degree with a the seat being about .060".
Intake seats will be 15/30/45 degree with the seat being about .050".








Another fun Packard project!

Perfect, sounds like you are on the right track.

Don't forget to remeasure the valve stem to lifter clearance when you are done. Grinding seats and refacing the valves can cause the valves to sit lower and close up the clearance on the end of the stems. So you might need to reface the valve stems on a few of them as well.

Quote:

Yes, after seats and lapping, I'll measure the stem up and get my engine builder to tip the stems if necessary. Previously they were all ground to about .040 clearance using Gauge J-4540, which is about the middle of the range.

A fun project, and excited to hear it purr when I'm done!