Vet76te

I will be replacing my valve stem seals on my 1965 with a 365hp 327. Does anyone have an opinion on using the umbrella seals instead of the original O-Ring style? If so, which seal did you guys use? Is there a different seal for the double hump heads, or do all 327’s use the same seals?

leif.anderson93

The most effective valve-guide seal for street engines is the Viton rubber seal. The Viton rubber is far more heat resistant for durability while still able to seal even a loose valve. The ones listed below require machining of the valve guide...unlike factory style O-Ring seals that ride on the valve, these seals attach to the guide. I have these on my '67 L79.

Amazon

Amazon

John BX NY

Do the Viton seals allow enough oil through for stock valve guides ?

pop23235

65 heads were 461 castings and the same double hump casting used for 64 & 65 300 hp, 65 365 hp engines. I’m not sure about 66 year. There is very little difference on the topside of any small block head of this era.

plaidside

Read my article, it might help you decision.
Joe

Vet76te

Thanks, Joe. Great article and helps a lot. One question, have you ever used the “rope method” to hold the valves in place? Pushing a small piece of rope into each plug hole, then rotating the cylinder to get the piston on top….and the rope takes up the empty cavity, and holds the valves closed. I’ve been told there is less of a chance of breaking the hold and dropping a valve into the cylinder this way. Any thoughts?

claf

When I did my 327 over a number of years ago, the valve guides were a "little" loose. As a very frugal gentleman rather than have them replaced I chose to use both the umbrella seal AND "o" rings. Thirty thousand miles later they are still doing the job. No smoke or excess oil consumption. I was a little concerned at first that they would work too good but it turned out to be a good fix.

Vet76te

quick question, Joe. In your photos, the valve stem umbrellas shown are two different types, a blue looking set and a white looking set. I’m assuming this is the difference in intake and exhaust. Which goes on which?

plaidside

Yes I have, wife's father broke a couple of valve springs on his boat and I didn't have a compressor at the dock so I had to use the "rope method".

quote:quick question, Joe. In your photos, the valve stem umbrellas shown are two different types, a blue looking set and a white looking set. I’m assuming this is the difference in intake and exhaust. Which goes on which?
In the article, the engine was an 82 Vette and they came with the two types of umbrella seals The blue ones for the intake and the white ones for the exhaust. The guides were machined for these "positive seals" from the factory. On our older engines, use the FelPro o-rings and the rubber umbrella seals stated in the article because the guide bosses are not machined.
Here is a paragraph from the article:
"This procedure was done on my wife's 82 Vette. It has a positive valve seal and the common O-ring seal.
Most older small blocks used only the o-ring seal, but I recommend using, in conjunction with the o-ring, FelPro SS5112 and FelPro SS10058 umbrella seals. They will fit inside the inner damper spring.
If you only have the O-ring and are going to use the umbrellas then substitute the umbrella seal for the positive umbrella seals in the photos. All other steps still pertain."