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I'm no mecahanic so>>> 1950 series 23, 288, recently had a major overhaul and reassembled with very close supervision from a highly experienced mechanic. Ran well for the first three hundred miles, although a bit on the hot side. Recently developed a miss, comp test shows zippo on cylinder 5. Pulled head, appears gasket didn't seal properly despite torqueing and redoing same. Had head replained, machinist said prior shop didn't do a good job. Putting it back together w/new hea gasket and retesting compression very soon. Anything I can check b/4 resetting the head. If I have no compression again, why? What is the next move? Car has 39K miles on odometer but suffered from to much no use.

Since you had the head milled or replaned I would check valve clearance just in case the head had been milled before and now too much is gone. Several have learned that lesson the hard way.

Lay the head on the block without the gasket and rotate the engine a couple of complete turns so all the valves have a chance to cycle. You can use some modeling clay above each valve edge and check that the valves don't raise enough to touch metal or leave only a very thin layer in the clay next to the combustion chamber. Without the clay is a bit harder but you can watch very carefully that the head doesn't move at all when the engine is rotated. If clearance is OK without the gasket then it will be even better when gasket is in place.

Thanks, Howard. Will do. Appreciate the help.

Thanks, Howard. Will do. Appreciate the help.

One more time, please refrain from surfacing the head from these flathead engines unless it is essential. One time too many and you run out of clearance for the valves; there is no practical way to reverse the process so all you've made is another boat anchor - we have too many already and the supply of suitable heads is not endless.

Good Morning all...I have a question that goes with this discussion. At what point should a head be planned? Are there a couple of minor problems that might lead us to want to plane a head that should not be planned and are there a couple of problems that would definitely make it necessary to plane a head? I think guidance in this area would be very helpful to many who don't know how to judge these problems correctly. Thank you, Ernie in Arizona

Ernie, I suspect Ross Miller has more experience with this than any of the rest of us and IIRC he has commented once or more often about his opinion for the max warpage before requiring surfacing; perhaps someone can dig out his advice or he'll see this and comment. A local machine shop here that has done a fair number of L8 engines has told me they like to resurface if warpage is 0.010" or more. Another reason to resurface is if you have significant etching or erosion around the tween-cylinder webs and water jacket openings.

I very seldom machine heads unless there are signs of erosion around the various coolant holes or on the narrrow area between cylinders.

I measured once and found that I could deflect a 327 cylinder head supported at the ends .002 inches with my thumb. Since each stud is pulling down with roughly 900 pounds I decided to go find something else to worry about.

Good Morning Ross...What an interesting comment. I would have never thought that a person's thumb could move a Packard head like that! We/I learn something new on this site every day that I have time to open it and read. Thanks very much for schooling me. Ernie in Arizona

All was well on the resurfacing, plenty of valve clearance.