Re: Will PermaDry leak if I dont use the load spre
First, you need to understand the leak mechanism. Most valve cover gaskets, once installed, project far enough inboard that the inner edge of the gasket forms a "ledge" that traps hot oil that runs down the inside of the vertical wall of the valve cover so it "pools" in the crevice where the gasket meets the inside of the valve cover, and leaks between the valve cover and the gasket - much less common is leakage between the gasket and the head. If the valve cover flange is perfectly flat, the gasket is not distorted, and the head surface is in reasonably good shape, it MAY not leak. These conditions seldom exist, however, although aluminum covers are less prone to leakage than steel due to the flange being stiffer. Make sure the flange is flat (especially adjacent to the bolt holes, where they're usually distorted due to over-torquing) and clean the surface; apply about a 1/8" bead of Permatex Ultra-Copper RTV to the center of the flange all the way around the cover, encircling the bolt holes, and apply the gasket to the cover, ensuring it's fully seated. Let it sit for an hour or so and install it, lightly torquing the bolts. After about an hour of running time, the gasket will absorb some oil and expand a little, conforming to the sealing surfaces - re-torque the bolts (to spec), and you should be in business. I've been doing it this way for many years, and have NEVER had a leaker, and there is no visual evidence of any sealer.
When Chevrolet completed their "dry engine" seal redesign program (finally!) in the mid-80's, the new (centerbolt) steel valve covers were redesigned so the vertical walls of the covers were extended down below the seal surface, then turned back up again to where the seal flanges mated with the gaskets; not rocket science - the oil running down the walls of the covers dripped off the bottom radius of the covers, and didn't get anywhere near the gaskets, which were "uphill" from the low point where the oil dripped off; the new aluminum covers just extended the inner wall of the covers as an extended flange, which accomplished the same thing (the head castings had to be redesigned to provide more depth inboard of the seal surface to accommodate the 180-degree formation in the steel covers and the extended flange on the aluminum covers).
First, you need to understand the leak mechanism. Most valve cover gaskets, once installed, project far enough inboard that the inner edge of the gasket forms a "ledge" that traps hot oil that runs down the inside of the vertical wall of the valve cover so it "pools" in the crevice where the gasket meets the inside of the valve cover, and leaks between the valve cover and the gasket - much less common is leakage between the gasket and the head. If the valve cover flange is perfectly flat, the gasket is not distorted, and the head surface is in reasonably good shape, it MAY not leak. These conditions seldom exist, however, although aluminum covers are less prone to leakage than steel due to the flange being stiffer. Make sure the flange is flat (especially adjacent to the bolt holes, where they're usually distorted due to over-torquing) and clean the surface; apply about a 1/8" bead of Permatex Ultra-Copper RTV to the center of the flange all the way around the cover, encircling the bolt holes, and apply the gasket to the cover, ensuring it's fully seated. Let it sit for an hour or so and install it, lightly torquing the bolts. After about an hour of running time, the gasket will absorb some oil and expand a little, conforming to the sealing surfaces - re-torque the bolts (to spec), and you should be in business. I've been doing it this way for many years, and have NEVER had a leaker, and there is no visual evidence of any sealer.
When Chevrolet completed their "dry engine" seal redesign program (finally!) in the mid-80's, the new (centerbolt) steel valve covers were redesigned so the vertical walls of the covers were extended down below the seal surface, then turned back up again to where the seal flanges mated with the gaskets; not rocket science - the oil running down the walls of the covers dripped off the bottom radius of the covers, and didn't get anywhere near the gaskets, which were "uphill" from the low point where the oil dripped off; the new aluminum covers just extended the inner wall of the covers as an extended flange, which accomplished the same thing (the head castings had to be redesigned to provide more depth inboard of the seal surface to accommodate the 180-degree formation in the steel covers and the extended flange on the aluminum covers).
Comment