Gasket Training Manual
The philosophy of ROL Manufacturing is simple when it comes to manufacturing sealing components for an automotive or light truck engine: be a basic manufacturer and use high quality, OE approved materials to assemble a durable product that will last the life of the engine!
MATERIALS   COATINGS
The materials that ROL uses have been tested over generations of engines and designs and under every conceivable operation condition. The facing materials used on cylinder head and manifold gaskets are a blend of non-asbestos materials like
Kevlar ® (a synthetic aramid fiber developed by Dupont ) or Graphoil ® (a natural graphite). Both materials offer unique as well as similar characteristics that lend themselves well to a wide variety of sealing situations.

Once the facing material is chosen based on the operating conditions and characteristics of the engine, ROL Engineers then select the best method of attaching it to the metal core material. There are primarily two methods of attaching facing material to a metal core. There is the chemical bond process where an adhesive is applied to the facing material allowing it to bond to the steel core. This works well in low temperature, stable situations such as normal driving conditions. The other method is to pierce the metal core with a series of punches that cause tangs to protrude up and down from the steel. The soft facing material is then applied to each side. Tremendous pressure is then applied that causes the tangs to penetrate the facing material, roll over and aggressively grip the material. Since this is a mechanical bond, it is ideal for extremely high temperatures that would breakdown the chemicals in an adhesive bond.

 

The types of coatings and sealants used on a gasket are critical. ROL Engineers first look at the engine to see if there are any unique sealing problem areas that need to be addressed such as a high-pressure oil return hole or a high temperature water hole. These types of areas may require concentrated pressure to insure no leakage occurs and there is a long term, positive seal. Creating a mechanical bead with an embossment or applying a silicone bead by a screen-printing process accomplishes this. Finally a coating is placed over the entire surface of the gasket.

The coating must protect and preserve the gasket from moisture and corrosion. Next it must provide a positive initial seal so no weepage occurs before the engine is run. It must provide long-term, positive sealing for the life of the engine. ROL uses POWERSEAL, a high temperature, ultraviolet (UV) cured silicone based compound that provides a lifetime seal. Sometimes Exotic coatings such as Moly (Molybdenum-Disulfide) where added lubricity is necessary. ROL does not use dyes or gimmicky colored pigments that do nothing to enhance the seal. Instead, ROL uses the most effective sealant required by the gasket application.

PROCESS   DIMENSIONS

ROL Engineers begin the process of manufacturing a
gasket by first examining the engine for which it is to be used. They look at its size, configuration, power, inherent weaknesses, material and fuel delivery system. The Engineers choose the gasket materials and construction that best suit those parameters rather than take on universal material and construction and adapt it to the engine. ROL believes their approach is superior because the “one size fits all” approach cannot reliably work in sealing all engine situations.

 

ROL Engineers examine critical dimensions of the gasket. First they look at the compressed thickness of the gasket. From years of testing and design they know that a typical composite gasket compresses approximately ten percent during the torguing stage of installation. The Engineers also know that during the teardown and rebuilding process the cylinder head and/or block is resurfaced to remove any imperfections and distortions that may have occurred during operation of the engine. In order to restore the geometry of the mating surfaces to the original OE specifications, ROL Engineers make the gasket thickness slightly greater for aftermarket use.

Secondly, they look at the bore size. In some severe duty situations, the cylinders of a rebuilt engine must be bored and enlarged to clean them up. In order to allow for this, the bore sizes on the gasket for aftermarket use are enlarged slightly to accommodate any over boring. This is only done after careful consideration is given to the effects on emission standards and operating temperatures.



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