Exhaust Valve Spring (RE15959)
- Rolls-Royce Silver Dawn, Silver Wraith & Silver Cloud I
- Bentley MK VI, R-Type & S1
This spring is from the engine section in the Rolls-Royce & Bentley parts catalogue for models built between 1946 to 1955.
Valve springs in an engine can cause a variety of driveability and performance problems. Every valve in the cylinder head has at least one spring. The valve spring exerts pressure against the valve retainer to keep the valve closed. When the rocker arm in a pushrod engine moves and pushes the valve open, the pressure exerted by the spring increases. The pressure maintains valve lash in the valvetrain, and pushes the valve shut again as the rocker arm rotates away from the valve. To maintain correct valve operation at normal engine speeds, all the valve springs must exert a certain amount of spring pressure. Weak valve springs will typically cause misfiring and a loss of power as engine speed increases. If a valve spring has failed (broken), it may not be able to hold the valve shut at all, causing a steady miss and loss of power at all engine speeds. Worse yet, a broken valve may allow the keepers that hold the spring retainer in place to drop out, allowing the valve to drop down into the cylinder head and combustion chamber. This will usually destroy the valve and/or piston and cylinder head, causing a catastrophic engine failure.
All our parts branded Prestige Parts have a 3 year warranty.