# '71 455 valve guide seals



## gjones (Oct 8, 2012)

O.K. Got Fel-Pro head gasket kit with new valve seals. Came with two types of seals. O rings & positive intake seals. When we got this engine, po. said it needed new valve seals. When I removed keepers, spring retainers, & springs, the loose-as-a-goose o rings were about midway down the valve stem, and no intake seals at all. I've lapped valves and changed seals in several heads about 25 years ago or so, but don't recall anything quite like this. I assembled an exhaust valve by installing the spring and retainer then compressed it, installed the stem seal into the second notch down from the end of the valve with the installing tool, installed the keepers, and released the spring. Is this correct? Do I need to install the Positive intake seals along with the o rings on the same intake valves and guides? These intake seals have a metal spring band around the center. Seems a little tight to go on. Is there a trick to install these properly? Can I use Marvel Mystery Oil to assemble the seals, or 10w40, or what? Also, were the old o rings installed improperly to begin with?


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## lars (Sep 28, 2004)

The original configuration from the factory was a single "O-ring" seal installed in the second groove down, just as you have done. This was used in conjunction with a stamped steel deflector shield installed over the spring to keep direct oil splash off the valve stem. As long as the valve stem-to-guide clearance is in-spec and all parts are properly installed, this system works just fine.

If the seals were installed halfway down the valve stem when you disassembled it, the PO installed them wrong, and they were almost ineffective. There is no way for a correctly-installed O-ring seal to come out of the groove once captured and retained there by the valve spring keeper.

Top-end gaskets kits, such as your Fel-Pro kit, will also come with an umbrella seal for use on the intake valves. If you have sloppy valve guides, these seals can assist in oil control and help reduce oil consumption. The problem with these seals is that they are designed to slip over the as-cast valve guide bosses, and these tend to be irregular in size. So they tend to not fit very well, and they should normally be used as a temporary measure. If you want to do the job "right," the heads should be removed, the guides should be properly sized, and the guide bosses can then be machined to accept a set of "real" PC seals that fit and function as they should. This will allow you to use a set of nice, high performance valves, which normally are not supplied with the second O-ring groove.

Lars


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