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

I know that when I head the head done for my 1966 Chevelle
230 six cylinder, the rebuilder would have refused to do the head unless he could install new valve springs.

He said that over the years the metal in the springs tends to fatigue.


John F. Shireman

Standard procedure is to first visualy inspect the springs, measure length. If suspect, then use a spring tester to test the springs.

Both Bob51 and Owen also cite critical issues to address as stated above.

John. There is no reason to replace springs if they are within spec. I'm currently running the factory original set in my 88 Ranger with 174K torturous miles (all driven by ME) which includes 1 episode of overheating. EVERYTHING else in the OHC head had to be replaced except the springs.
I have replaced springs AS NEEDED in probably less than 10% of the engines i've overhauled and then it was only maybe 5 or 6 springs in any one engine. I've never had one come back. ONE exception is EXTREMELY hot running engines such as m/c engines. About 20K miles will max out Chief springs . Sometimes 5 or 6K miles will weaken the springs. the big 2" valves don't help either but the Chief engine is an extreme case.

OHV and OHC engines the springs are rather ez to replace anyway without head removal. Flat heads can be a pain in the ass. I don't know about the Packard streight 8. Can the springs be removed without removing the head???

Quote:

Of course they can.

The springs were very different in height. The major difference was between the springs on the intake valves vs the springs on the exhaust valves. The difference was so consistent that at first I thought Packard used two different spring lengths for exhaust/intake but a check of the parts manual proved that not to be the case. I will add a photo and some measurements of the old valve springs later today.

Turbopackman... Hey, I'd really like to know how you'd remove a valve spring on a 356 without taking off the head. I've got another one to do next year.

Look in the manual, parts cataloug or using KNOWN NOS parts determine the spring specification. It will give the specs in LENGTH and/or tension pressure and service limit range.

On the next engine use tha t criteria. IF NEW REPLACEMENT SPRINGS are used CHECK the new springs against the criteria.

If the NEW springs are TOO long or to STIFF then that is just as much a potential problem, actualy worse, than springs that are too short or too weak.

J.D., by using one of these:

Valve spring compressor

I've used them several times without pulling the head, just make sure that the lifter is on the down stroke!

You are joking, right? Sure, that's the preferred valve spring compressor, I've probably worn out more than a few over the years doing valve jobs on flathead Packards, Chrsylers, etc.

But you can get the spring out without removing the valve? On the hydraulic lifter engines you can't even remove the lifter body to create space below the valve stem without pulling the valve, which of course requires removing the head. And even if you had mechanical lifters, how do you get the spring coil wound out thru the few thousands of space between the stem and the lifter?

Any pictures to demonstrate your method? We are talking about the flathead engines here, right?

I got an almost identical valve spring compressor off of e-bay before we started. But compressing the spring doesn't remove it. As O_D says above... there's just no way to get it around the valve and lifter without removing one or the other or both and you can't remove them without removing the head. In fact, with the Packard 356, all you can do with the valves and lifters without pulling the head... is admire them! A fact the mechanic griped about on more than one occasion.

OK. Here are the pictures. It is obvious that I wasn't nuts... the springs ARE different. It's no wonder that we had spring problems. The difference is approximately 1/4 inch. Sorry I don't own any micrometer tools, just a worn out tape measure (non-metric).

The distance from the keeper to the valve face was different on the intake vs exhaust valves also. The keeper on the old intake was lower (more distant from the valve face) than the keeper on the exhaust. The keeper notches on the old valves were different depending on whether they were intake or exhaust (see pictures below).

The new valves used the same keeper notch and distance on both intake and exhaust and, of course, the same length spring.

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When I took the valves out of my 356 engine the bottom of the valves were marked "Packard". I wonder if some long ago (or not so long ago?) engine rebuilder used other than Packard valves to redo the engine and substituted incorrect valves and springs. The intake valve keeper notches don't look like Packard ?