Re: valve stem seals

Posted by PackardV8 On 2010/3/23 12:59:58

The umbrella seal that rides on the stem of the valve is NOT the only seal. There is a seal on the valve spring retaining collar too. What did u do about that seal??????

IIRC my 56 Executive had the umbrella seals on ALL 16 valves. Did your engine originaly have umbrella seals on all 16 valves??????

I did not use the Packard umbrella seals on my last valve job. I used a MoPar rather shallow and wide such umbrella seal on all 16 stems but that was not what i really wanted or is needed.

Here is the problem: The seal that rides on the stem (NOT seals that press over the valve guide) will deterirate very quickly and break up and go into the pan and plug up the oil pump screen.

If u have another Packard V8 that is RUNNING then conduct the following test:
Remove the left valve cover and get out and drive the car. U will see that very very little oil ever gets to the stems let alone ever so much as splash a few drops out of the engine. Believe it or not.

Under NO circustance would i use the (sometimes called umbrella seal) seal that presses down over the guide. Those are for overhaead CAM engines not OHV engines. They are used on ohC engines because ohC engines sling so much due to the cam.

Many 'hot rod ' shops and current engine builders use the press-over-the-guide seal on ohV engines. Then they wonder why the valves guides wear out so fast.

AGAIN, conduct your own test by removing a valve cover and watch the oil flow. The Packard V8 barely delivers any oil to the stems at all. (EXCEPT early 55 V8's)

This is NOT true of very early 55 V8's with the pee-hole rockers.


My advice is to not use any umbrella on the stems (EXCEPT earlyy 55 engines with pee hole rockers).

The Packard V8 engine overhead was poorly oiled. A better seal arrangement is needed more like that of the SBC with a shedder over the spring.

To answer your initial question i would definately NOT put umbrella on the exhaust. Intakes ok MAYBE.

The most important seal is the seal on the valve spring retainer.