Packard Forum Index » Post-War (1946-54)

I'm sure there has been a detailed explanation offered however, I have searched the post war Packard blogs and specifically used 356 hydraulic valve adjustment as "key word". Several replies have shown "not likely necessary since they are hydraulic lifters" and "gauge block is needed for the 356 (specific) valve adjustment. Would that gauge be used for the clippers etc with 356 which I think have solid lifters or have I missed something here. (chances are pretty good that I've missed something....again)

Believe all 356 engines from the 1940 introduction onward had hydraulic lifters so there is no adjustment as such. The plug gauge is used to verify the length of the valve stem when installing new valves or after grinding old ones that might have resulted in a lowering of the valves in the block enough to change clearance to the lifter. The same idea but a different dimension gauge is also used on later 288/327/359 hydraulic lifter engines.

A lifter could have failed or have a speck of dirt under the checkball causing a noise. The small curved pigtail tubing connecting the oil pump output port to the valve lifter gallery could have issues resulting in low oil flow to the lifters which would let them get noisy.

On the early 356 engines there was a valve which admits oil from the lifter gallery to the timing chain area which could fail resulting in low oil pressure to the lifters causing them to be noisy. That valve was changed in 42 production so should not be an issue on postwar Clippers.

If you need a gauge Pacific Northwest region reproduces them.http://pnwpackards.com/styled-2/index.html

Howard, Thanks for the quick reply. Yes, there are about 8 new valves and 8 of the original ones. The engine shop is typically a small block specialty performance shop but are happy to do the rebuild. they are just trying to find the magic formula for making sure the valves are seating properly. I thought I had seen that somewhere here over the past four years but can't seem to locate that detail now.

They do have the shop service manual for the engine clearances and torque specs which I gave them last fall. A long story but things are starting to come together....finally. Engine block has been to charlotte Nc to have the cracks in block repaired then the crank went to Indiana to have the counterweights removed, crank turned and then CW's reinstalled. All the pieces are back under one roof again.....

The procedure for using the gauge tool is to remove the lifter from the tappet body. Insert the gauge tool in its place and then insert the valve in the block and guide. Put light pressure on the valve head to ensure it is tightly held against the seat. Use a feeler gauge between the stem and tool and check clearance. If the stem is too long grind the end of the stem as needed (keeping the end square) to bring the clearance into spec.

On the machinist following book specs -- pistons, if they are originals or NOS from one of the vendors then factory clearance specs are good but if the pistons might be repros then I would verify the skirt clearance with the paperwork from the mfg of the pistons. My machinist installed Egge repro pistons in a 56 engine using factory clearance specs. Those numbers turned out to be too tight for the particular repro pistons. One piston seized and another was almost at failure after just a few miles so I have first hand experience on what not to do when factory specs and some aftermarket items are mixed together.

I suppose it's obvious but when using the procedure above for the hydraulic tappet clearance adjustment, first make sure the cam lobe is DOWN.

Thanks to all for the input....I think the shop is on the right track now. (FYI to all, never assume I see the obvious...it usually takes repeated blows with a blunt instrument for things to sink in)
I will eventually chronicle the path this project has taken over the years. Look for "Exorcist Needed-experience preferred-provide resume" topic