Federal-Mogul Corporation has introduced a new range of sealing products under its Payen brand that are aimed at prolonging the life of cylinder heads in engines.
The ‘HeadSaver’ is a simple concept – a stainless steel shim which, for most engines, is inserted between the top of the engine block and the cylinder head gasket.
Federal-Mogul’s research and development team pinpointed a growing need for such a product to compensate for material removed from cylinder heads during the resurfacing often necessary when a cylinder head gasket requires replacement. This helps overcome excessive distortion or warpage as well as any impressions left in the head face by the bore seal of the removed gasket.
Cylinder head resurfacing is becoming commonplace today, as most engines use aluminium alloy cylinder heads, which tend to be more prone to distortion and damage than their cast iron predecessors. This makes it critical that the cylinder head surface is flat during the engine rebuild; otherwise the new head gasket is subject to failure. Worse still, a frequent by-product of machining a head is a notable increase in the compression ratio of the engine, which can affect performance and emission characteristics as well as potentially lead to serious engine damage.
A solution was needed to both ensure the appropriate flat surface was achieved and also to restore the engine’s compression ratio.
‘We looked at thicker gaskets as an obvious potential solution to this problem, however it is not easy to manufacture over thick head gaskets,’ said Payen Technical Director Paul Saunders. ‘Our US colleagues had been working with a head saver shim for some time and the concept was proven so we developed the product for use on European engines.
‘The Payen HeadSaver is used together with a standard cylinder head gasket,’ added Paul. ‘The gasket is still required in order to seal combustion gas and fluids, as well as to compensate for the dynamic stresses seen on an engine in service.’
Payen HeadSavers are manufactured from stainless steel and match the geometry of the appropriate cylinder head to create optimum sealing performance. They are durable and offer a surface finish that can accept all types of cylinder head gasket designs. The manufacturing process helps ensure that the stainless steel does not distort, so the gasket seals against the necessary flat surface.
The net effect of the HeadSaver is to prolong engine life as well as to prevent the cost of a replacement cylinder head. The product range initially includes 14 different variations, with plans to introduce additional part numbers as required to meet market needs.