The valves are driven by the camshaft and rocker arms and tappets and allow the mixture of fuel and air to flow into the combustion chamber. This mixture is then compressed and ignited, the remaining hot exhaust gases are discharged through the exhaust valve.
The flow of inlet and outlet gases must be carried out with as little resistance as possible; for this purpose, the materials must be specially developed to allow the gases to pass through properly, without resistance. The inlet valve is larger than the outlet valve to allow as much mixing as possible in the cylinder.
The valves are highly loaded, especially the exhaust valves. These become very hot and can be cooled slightly, unlike intake valves, which are partially cooled by the intake air-fuel mixture. But most of the heat is dissipated by the valve seats and valve rods.
It is important not only that high quality valves are installed, but also that the engine is optimally adjusted. Damage due to valve failure or overheating is often due to improper adjustment. Therefore, make sure that your engine is always perfectly adjusted and, if the valve clearance has to be adjusted manually, that it is done in accordance with the prescribed adjustment data.
When overhauling the engine, we recommend that you always replace the valves, in most cases you do not know how long they have been in service. The valve must close optimally, run them in the seats with abrasive paste and perform a leak test, only then can you be sure that your valves close perfectly.
The valves listed here are standard valves that replace the original valves, but we recommend protecting the valve stem with caps, thus avoiding the impact of the valve stem by the adjusting device (if available for the valve concerned, these are listed under the Options tab).
Please note: check the dimensions before ordering, if the cylinder heads have already been replaced, the dimensions may differ from the original ones.
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