Text from page 30 of catalogue Cylinder head gaskets
Page 30 of catalogue Cylinder head gaskets of Reinz-Dichtungs-GmbHSpecial solutions
»BACKLAND« STOPPER REDUCES COMPONENT DISTORTIONS
The maximum compression height of the combustion chamber beads, and the clamping of the surrounding components, have a decisive influence on the sealing potential and service life of the entire sealed joint. By integrating an additional backland wave or trapezoidal stopper, combining these two elementary functions enables the reduction of component distortions introduced by high bolt forces and the gasket, and permits selective application of the force lines. At selected points in the backland of the head gasket, additional wave or trapezoidal stoppers can be integrated as supports. Compared with the combustion chamber stopper, these elastic/ plastic stoppers have a reduced height, and can also be designed with individual height profiles for topographical adaptation. These options can provide additional support for the outer cylinders, thus counteracting cylinder head flexure as well as distortion of cylinder liners and main bearing webs. Correct
matching of the backland stopper, combined with specific topography of the combustion chamber stopper, enables an identical pressure image to be obtained at the outer sides of the first and last cylinders.
FLAT SHEET Seals »BLOWHOLES«
It’s a common problem: shorter cycle times during the production of cast components such as Engine blocks, cylinder heads, or timing covers lead to an increase of entrapped gases, or ”blowholes”, which represent a growing microsealing problem for head gaskets. The patented flat sheet from VICTOR REINZ can help alleviate this micro sealing problem. The resilient top or bottom sheet ensures effective pressure distribution over a larger area. Due to its outstanding yield properties, the elastomer coating on the component side is pressed into the blowholes and seals them reliably. The coating can be applied to the flat sheet over the entire surface or partially, and in variable layer thicknesses.
10.9 Bolt quality without backland wave
Cylinder distortions enlarged 400 times
10.9 Bolt quality with backland wave
Stopper layer with topographical backland stopper.
Comparison of cylinder shape without additional measures, and with integrated backland stopper.