Re: valve stem seals

Posted by PackardV8 On 2010/3/24 6:29:26

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".