I am in the midst of a rebuild and have disassembled the cylinder head and valves. I did not find any evidence of valve stems oil seals. I expected to find disintegrated bits of some kind of rubber. Since I didn't, I took a look at the The master parts manual (1929-1954) cylinder head exploded view. It shows these parts: .303 the valve spring .308 called a cover .309 called the cap .310 called the key .311 called the seat but no oil seals. did the 216 have valve stem oil seals? Now I am confused about the difference between the cover and the cap. The picture was not clear enough for me to tell.
I know I have one of them, but I always called the part on top of the spring the valve spring retainer, and the retainer was held in place by the 2 valve keepers and the spring pressure. did all engines have both a cover and a cap? does anyone have a photo of the cap and/or cover?
The attached snip from the intake valve listing may explain what you found. The exhaust valve listing is similar, with pre-1941 valves showing only a single groove What's the date code on your cylinder head. Maybe it's a 1940 or earlier. And the figure you looked at likely was as well. I know that I have disassembled one 216 head (a '51) and it definitely had o-ring seals on the valves. As I recall it had the bottom and top spring plates and keepers along with the seals.
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texas46 - The O-ring seals didn't come along until the 1947 model year. The 1946 and earlier engines used a "cover" (Group 0.308) as the spring retainer with the keepers as you mentioned. Intake valve covers are round, while the exhaust valve covers are hexagon shaped.
According to Page 6-24 of the 1942-46 Chevrolet Car and Truck Shop Manual:
"Valve spring cap covers, of an umbrella type are used on all intake valve stem ends. The cap covers are designed to carry oil which flows down the rocker arms to lubricate the valve end of the arms, out over the intake valve spring. This reduces the amount of oil reaching the intake valve stems for guide lubrication, thus controlling oil consumption and smoking when the engine is idling."
The Group 0.309 listed as a "cap" is better identified as the valve spring "Cap-rotator assembly" which is unrelated to oil control, but meant to extend valve life.
Attached is a screenshot from a 1942 Shop Manual (same picture as I have in the 1942-46 book) which you can kinda see everything. Sorry for the poor quality of the pic.
Last edited by Gdads51; 03/03/20262:05 AM. Reason: added 2nd pic from parts book
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thanks for the insight I read and reread that same quote from the manual and couldn't really make sense of it. Now I know why. It is now apparent to me that my engine does not have any caps at all. I am certain someone threw them away during earlier valve job. They also managed to lose one of the lower spring seats.
