Piston Rings Set 75.0mm

A high quality Ductile Iron Piston Ring ensures sealing, lubrication and heat conduction between the piston and cylinder wall. Cast iron beds-in easily and is a durable wear surface in normal operating conditions.

• Top Ring 2mm Cast Iron
• 2nd Ring 2mm Cast Iron Napier
• Oil Ring  4mm 3 piece flex vent with chrome rails

This ring set suits many piston brands including Mondial pistons fitted to Laverda 1000, often suitable for re-ringing after a light hone. Ring end-gap tolerance 0.254 to 0.508mm

Notes When Re-ringing Used Pistons: Maximum ring gap is an important part of ring performance in that too much gap results in lost compression, power loss, and ultimately poor oil control. Due to piston to bore clearance after honing a used bore, the end gap may be near to or at the maximum gap range. It is the installer’s expert judgement in analyzing the primary use of the engine that should lead him in a direction of which ring set will be the best possible choice for a particular engine. 

In order to check ring gap, the rings should be placed at the lowest possible part of the cylinder (below ring travel area) as this is the portion of the cylinder that is unworn and which the ring is sized for. Checking ring gap in the worn portion of the cylinder will show a gap increase in direct relation to the amount of cylinder wear present. For example: In a 4" worn cylinder it may be found that the tapered cylinder has .012" wear at the top portion of ring travel, which increases the ring gap .036". Therefore, it is entirely possible for the ring to have .061 end gap in that portion of the cylinder and be within recommended manufacturing tolerance.

For this reason it is recommended to maintain a MAXIMUM of .003″ wear per inch of cylinder diameter, not to exceed .012″ in any case for successful re-ringing. If a cylinder is worn in excess of this it should be rebored.