Z20 Valve stem seal retainers plus a fresh set of stem seals
The Z20 engine has a bit of a habit of blowing off the valve stem seals with high boost, particularly on the exhaust side. These little gems will keep them held down throughout the most arduous race use.
Precision CNC machined from Stainless Steel they are designed to be used with standard type stem seals and both double or single valve springs.
These are cheap insurance against the dreaded smokey idle that these engines are notorious for.
Note:- On anything serious we lightly hone the inside lip off of the exhaust side stem seals before fitting. This stops them gripping as tightly to the valves, and lets just a little bit of oil make it's way down to keep the stem seal from melting to the valve stem and ripping off. Intakes are fine as standard. Do not use any sealant on them.