Sitting atop a valve and keeping the valve springs in place are these standard Ford Kent retainers. These are the same style as used by Ford on their Crossflow and Pre Crossflow OHV Kent engines.
These are brand new units which will sustain regular race use in a Formula Ford engine for a number of race seasons.
We generally replace retainers on our race engines when we refurbish a cylinder head, however in a fast road application their lifetime should be in line with the life of the valves. We have pulled apart original running Kent engines that have over 350,000km and the original Ford retainers are still intact.
We sell these retainers singularly - a Kent engine will take 8 retainers for the 8 valves (4 inlet valves and 4 exhaust valves).