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

Well, now we're beginning to understand, you had some incorrect valves and springs installed. The OEM springs should all be the same height, and both intake and exhaust use the same keepers (spring retainer half-clips). Unfortunately we find all too often that some previous owner or mechanic did a botch-job. The original Packard valves did have Packard script logo on them but as these have dried up I've used MANY Egge valves with never a problem except on the old 320 and 385 engines with the broached slit for the keeper, once had one snap off at the broach.

Still hoping to hear more about a method to remove valve springs without removing the valves.

Owen, yes, I'm joking! BUT, I DID manage to get some springs out of my 327 without removing the valves, simply because the valves are stuck and won't come out. I had to "finagle" the lifter apart to get the spring out. The base of the lifter's still in the engine because I can't get all the valve train apart. I did have the head off at the time!

JD,

You have two distinctly different springs in the side-by-side comparison.

On the left, you have a straight rate spring with 6 active coils. On the right, you have a dual rate spring with seven active coils.

I am sure this is the result of replacement with what ever was available at the time, because there is no reason in the world I can think of for having dual rate springs in a flat head engine.

With that said, I am not sure how this would cause poor running. The springs were not broken, the valves should have been closing. Were he stems varnished up?

Jim

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Yes, all the old intake valves had the Packard script on them, the old exhaust valves did not. Re-using the old springs in this instance pretty much guaranteed failure. An expensive lesson. I can hardly wait to see what lurks inside the 1948 356 currently sitting in the '41 limo. At least I have a much better idea of what's supposed to be in there. I'll probably do a project blog on the '41 when I start tearing into the engine.

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Jim,
I don't know with absolute certainty that the mismatched springs and 1/4" difference in valve keeper notch distance caused the valves to remain open. It well may have been the new valves that cured the problem. But in any case with all new valves with standard keepers and keeper distances designed for a 356, it only made sense to replace all the old questionable length springs with springs that were designed for use with the new valves and keepers. As far as being varnished up, the old valves moved easily in the guides and did not have a lot of crud on them.

Don't forget when you get into your other 356 that if you machine-face the valves and machine-surface the seats, the intake and exhaust valve faces and seats are cut to different angles.

JD,

At the end of the day, if the replacement of incorrect parts with correct parts worked, go with it.

Jim

Follow Owens advice above about the different seat angles.

I don';t know what the 356 valve angles are but i'm guessing AT LEAST one of the Int or Ex. is NOT 45 degrees. This can present a problem for MANY machine shops and i've ran into it even at an old reliable well established shop i used.

The problem is that there is no longer much demand for seat angles that are NOT 45*. So the machine shops have NOT kept the seat stones maintaned. It's a bad case of the old SBC coming back to haunt us again. Based on my occasional visits to machine shops over the last 10-12 years about 80% of customer parts laying around in the shop for service are SBC. SO the 30-something degree seat angle service is not in high demand and the stones and 3/8 mandrels are not maintaned.

Look at the valves that came out of the recent engine u just finished. Check the seat angle on the valves to be sure they are not 45*. Is there a number or other identifying marks on the old valves?????

In many cases, some rebuilders wheather private or 'professional" are cutting hte old 30 degree seats and faces to 45* and retro fitting other valves to suit. These are things to watch for during tear down and inspection.

Most, if not all of the Standard and Super Eights with the aluminum crankcase and cast iron block were 45 degrees for both intake and exhaust, but I believe I'm correct in stating that the 120 and 110 and all from 1940 thru 1954 were 30 degree intake and 45 exhaust.