Re: hardened valve spring seats

Posted by Jack Vines On 2014/6/29 20:35:13
Quote:
The past repair for weak spring tension on head refurb was shims under the spring to restore seat pressure however wont this just aggravate our problems of collapsing lifters if running the stock oil pump? High spring seat pressures are only required with aggressive cams or high rpm. Driving the Packard conservatively should not create an issue, Is there a vin break point or build date to ensure hardened retainers. I assume the file test is on a torn down motor? I would worry about this test on an in service engine due to inducing a failure at the file gouge, as it could cause a stress riser and failure where there was none before. How often do these fail on say an untouched orig engine? All v8s an issue? 55 and 56?


Driving conservatively may save you, may not. There were so many failures in '55 that Packard hardened the retainers. Were all those owners abusing the cars, using aggressive cams or high RPMs? Doubtful, but the retainers still failed.

As to high seat pressures, didn't notice anyone advocating that, just what the Shop Manual says should be there. If the springs are too light, even using passing gear would be noticeably soft at normal RPMs.

I'd guarantee the file test on the outer edge of a retainer on an assembled engine would never be the cause of a failure from a stress riser. Just wouldn't happen. Retainers don't fail at the edge. The keepers pull through the center.

jack vines

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