Packard Forum Index » V-8 (1955-56)

im in the process of overhauling my 1956 352 heads,and need to know if i should put umbrella seal on just the intake valve or can i put them on both valves.i have a 78 ford f250 with a 351 modified and it had seals on both valves.why didnt packard put them on both valves is the question?.the gasket set only comes with 8 seals for the intakes,is there a place i can get ones to fit the exhaust valves.i know this thing is old but i dont want it to smoke to bad.

The short answer is that since intake valves are open as the piston moves down and creates suction, oil can be pulled past the guides/stems if there is too much clearance. But the exhaust valves are only open when there is the positive pressure of the piston pushing the exhaust products from the cylinder, hence the opportunity for oil to get drawn in is nil.

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.

What is the internal diameter of the umbrella seal supplied with the kit???

Another problem with the umbrella seals (that ride on the stem) on ANY engine is they will become hard and wind up sliding down the stem and over the guide thus starving the guide for adequate oil. THis usaly occurs at about 25K miles or so.

Use either a very shallow mopar type umbrella or NONE AT ALL!!!

The pACKARD v8 oil consumption problem is due to rings. Not over head oiling.

Your engine, your money, your decision.

As for me, I install the positive seals which require machining the valve guide bosses on all my Studebaker and Packard V8s. These type seals are used on most modern engines and were developed because the umbrella seals are old technology which didn't last and don't work very well.

Just so we're all referencing the same parts, umbrella seals are shaped like an umbrella and are a slide fit onto the valve stem and are not a drive fit onto the guide. Those which are driven onto a machined surface on the guide are called positive seals.

I'm also not sure I can agree the Packard V8 valve train is poorly oiled. Many other OHV8s show more rocker, valve stem and guide wear than does the Packard V8. Using today's much better oils, the rebuilt valve train rarely shows any wear after several thousand miles.

thnx, jack vines

I questioned my cousin, a good mechanic, about the lack of top oiling vis-a-vis 57 Chevy which resembles a fireboat. He stated that you didn't need massive quantities of oil at the top end. He said if you had a mist of oil up there, it was more than sufficient. I never found him to be wrong, although I did mount 55 exhaust rockers on my 400 when I redid the heads.

I drilled 6ix exhaust rockers (3hree on each side) ala early 55 Packard V8. Drilled and plugged the rocker shaft so that the oil squirts thru the rocker arm when valve is open rather than closed.

AS for the 'oil mist' lubrication concept that is mostly an old flat head valve lube design. If there is any sufficient oil mist in the overhead to lube the valves then why are the inside tops of the valve covers BONE DRY when removed after a hard run?????

SBC is not the only ohV engine that uses the massive oil delivery to the overhead. AMC 6 cylinder engines use a similar oiling.

My 56 Exec had 34K original miles on it when i got it. I have all of the papaer work and some maintenance records from original owner. At about 40K miles when i did the valve job i found that the guides were worn to clearence of .006' on most and .009 inch on one or two of the exhaust.

The Positive SEals (FROM PACKAGED OVERHAUL SETS) are presenting problems on ohC engines. Two recent cases that i know of. One of them my own. The Positive Seals are marked on the top with very tiny letters either "IN" and "EX". FACTORY seals ran fine for 150k miles. THe PACKAGED GASKET KIT had only seals marked "EX" for all 8 valves. Recent ex VALVE STICKING on a 2.0 F OHC engine has stopped (Thus far) by using NO seal whatsoever on the exh valves.
But that engine also has a shedder around the spring similar to the Packard V8 'Spring Baffles". *** MY POINT is that OVERHAUL KITS may not have correct seals supplied with them. ****

For passenger car applications the proof is in 30k to 80k miles of operation. Not just a run down a 1/4 mile track or a 500 mile run on memorial day weekend at 212 mph.


The problem here is that getting the CORRECT oil to the valves requires massive testing from engine to engine and many miles of testing operation. Since we are limited on the test bucks i prefer to err on the side of oil consumption rather than wearing out or hanging up valves before the first 30k miles are driven.

Oil consumption on my Executive was about 1 qt PRIOR to my overhead modification. STILL about 1qt on 700 miles AFTER.

The OHC F engine shows only a puff of smoke on start up.

I need valves that slide up and down the guides. NOT bragging rites that "she don't use a drop of oil".

Also note that there are MANY SC's and STB's covering the Packard V8 oil consumption. A few retracting earlier service procedures. There is one STB or SC that came out rather late. It indicates (paraphrasing) that "if all else fails then replace the piston rings".

Read those STB's and SC's with a vigilant and suspicious eye. My analysis on them is that PMCC was hedging. The problem is piston rings. PMCC was merely trying to avoid that costly problem by jerking the customer around with cheaper and easier bandaid type procedures such as drying up the overhead to bare necessary oil delivery.

not trying to fight here, but i have run my late 56 374 with the valve covers off, and it gets plenty of oil to the top end. it doest gush all over the floor while sitting there at+/- 500 rpm, but it would certainly make a titanic mess at road speed.