SPECIAL INSTRUCTIONS FOR STAMPED STEEL VALVE COVERS
Stamped steel valve covers require special attention when used with these adapter plates. Cast covers have a flat machined gasket mating surface that matches the flat surface of the adapter plate, thus the gasket seals between these two surfaces easily. The stamped steel covers are not nearly as forgiving. When stamped covers are used directly on a cylinder head the gasket mating edge on the head is much narrower therefore requiring less bolt torque to conform the gasket to any irregularities in the head or the valve cover lip. The adapter plate is flat and wide. Therefore, if the stamped valve cover has any irregularities at all a leak can occur. When using stamped steel pent roof valve covers on your new adapter plates there are two areas needing attention in order to avoid oil seepage between the adapter plate and the valve cover: 1. the outer lip of the valve cover itself and 2. the area around the bolt holes. FELPRO gaskets seem to be better for stamped steel covers because they have smaller diameter stud holes than VICTOR gaskets. FLASH: I recently found a superb set of FE gaskets that eliminates all the work outlined below in Steps 1 and 2. DSC Motorsports markets 1/4" thick and 5/16" thick cork FE valve cover gaskets that work like a charm. Visit their website to order. Glue the gaskets to the covers using Permatex Ultra Hi-Tack gasket cement. Use your temporarily assembled adapter plates as jigs. Allow the gasket cement to set up overnight before installing. A light application of anti-seize will prevent the gasket from sticking to the adapter.
1. The stamped steel valve covers have a gasket retaining outer lip that is usually not present on the cast covers. Since the gasket is thinner than the height of the valve cover lip, the gasket may not be allowed to obtain a firm seal on the adapter plate due to contact between the adapter and the lip of the cover. I highly recommend a trial fit prior to final installation to assess this potential interference. Assemble the valve cover studs (five) into the threaded holes on each adapter plate and fit the cover to the plate without a gasket. The adapter plate should fit within the outer edge of the valve cover lip. If there is interference between the adapter plate and the lip of the valve cover there are two possible remedies:
a. You may remove a small amount of material from the outer edge of the adapter plate in order to allow the valve cover lip to fit over the edge of the adapter plate. The best way to accomplish this is to set up a belt sander with a fine grit belt secured upside down on the workbench . With the adapter plate edge held perpendicular to the sanding belt carefully remove a small amount of material from the outer edge of the adapter plate until it fits within the lip of the valve cover and the studs are reasonably centered in the bolt holes of the valve cover. You may give a slight taper to the upper outer edge of the adapter plate in order to assist fitting the valve cover. Repeat this procedure for both adapter plate/valve cover assemblies. Then proceed to Item #2 of these instructions.
b. If you do not wish to remove material from the adapter plate you can use a double gasket between the adapter plate and the valve cover. You will need two pairs of FE valve cover gaskets for this option. Do NOT use cork gaskets. Use an adapter plate with studs installed as a jig to line up and match two gaskets. Using Permatex Hi-Tack gasket adhesive as a bonding agent, coat the sides of the gaskets to be joined as per adhesive instructions. Mate the two gaskets and apply even pressure using a valve cover bolted to an adapter plate, making sure that the two gaskets being joined are perfectly aligned. Allow the assembled gasket to set up overnight. This will ensure no leaks between the gaskets. Then proceed to Item #2 of these instructions.
2. The gasket mating surface of the stamped steel valve covers around the bolt holes may not have sufficient surface area contacting the gasket to prevent oil seepage around the valve cover bolts. This is easy to remedy. Use Permatex Ultra Black (Part #598B) hi-temp silicone RTV gasket maker (NOT the black standard silicone adhesive). Use your assembled adapter plate as a jig for the following procedure. Clean the inside of the valve cover lip with lacquer thinner for chromed covers or mineral spirits for painted covers. Apply a 1/8" bead of silicone gasket maker to the entire inner valve cover lip, completely encircling each bolt hole with the silicone. Assemble your single or double gasket to a valve cover and place the assembly on the adapter plate. Use the washers supplied with the kit and your retainer nuts lightly snugged down to hold everything in place. Make sure the gasket is properly seated and everything is assembled properly. Allow the assembly to sit overnight until the silicone is fully cured. After curing you may carefully trim away any excess silicone with a sharp blade or add an additional bead of silicone on the inside edge of the gasket if necessary and then proceed with regular installation of the adapter plates.
3. Stamped steel valve covers seem to require a little more torque on the bolts than cast covers in order to obtain a good seal. Since the metal lip on the stamped covers is thinner than cast covers the stainless washers provided in the kit tend to "cup" when tightened. To remedy this, purchase ten 1/4" SAE (NOT USS) grade 8 washers from your local hardware store (Lowe's or Home Depot carry them in cheap bulk paks). Placing a thin bead of silicone sealer around the base of each stud to fill any gap between the stud and the gasket will prevent oil seepage up around the stud. Place a grade 8 washer on each stud, then top with a stainless washer to maintain appearance. Then apply your nuts and torque to the proper setting (5-7 lb/ft).
This may seem like a lot of work but the reward should be a tight leak free installation that will give satisfactory long-term service. I use stamped chromed covers and DSC gaskets on my own Cobra and followed these instructions. There has been no seepage over two years now and I have even removed the covers twice to polish them. The gaskets from DSC Motorsports completely eliminated any seepage. I highly recommend them.
