MAHLE Oil Ring Support Rail Bore

MAHLE oil ring support rails (also called piston oil ring spacers or oil rail support rings) sit in the bottom of the oil ring groove. They support the oil ring assembly on pistons where the wrist pin bore intrudes into the oil ring land. They hold the oil ring assembly in position and keep it from rotating. This helps the ring seal against the cylinder wall and receive the gas pressure it needs at high rpm.

Key Features:

• Helps improve cylinder seal and minimize friction
• Keeps the oil ring assembly supported and stable in the groove
• Helps restore original new clearances and allows full compression to be restored
• Built-in dimple locates the rail in the wrist pin gap to prevent rotation
• Engineered by MAHLE, a leading name in pistons and piston rings with a long motorsports heritage
• Made in the USA
• Available in multiple bore ranges and thicknesses to suit different piston and ring combinations

Support rails go in the oil ring groove first, with the dimple down and located in the wrist pin gap. The oil ring expander and oil rails then stack above them. The rail should seat snugly against the back wall of the groove and should not overlap or contact the cylinder wall. Choose the correct bore range and rail thickness for your piston and ring set.