Engine Spares

Piston, liner & ring kit

Pistons, liners, ring sets, cylinder heads and the LPR kits that bundle them. Tell us the engine model and bore size, and whether you need standard or oversize.

A new diesel piston with its rings fitted, the gudgeon pin lying beside it

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What to send us

The number stamped on the old part is the quickest route. If it has worn off, the engine or genset model and serial number usually gets us there. Photos help more than descriptions.

We cross-check whatever you send against the OEM catalogue and confirm the match with you before anything ships.

About this range

An LPR kit is the liner, the piston and the ring set for one cylinder, usually with the pin and circlips. It goes in at overhaul, once compression has dropped, oil consumption has climbed, or the bores have worn past their limit.

Whether you can rebore depends on the engine. Wet liners sit in the block with coolant against their outer wall and are simply replaced, which is why you do not fit oversize pistons to them. Dry liners and parent bore blocks can be rebored, and that is where oversize pistons come in. Among the Cummins families the 4BT and 6BT are parent bore, while the 6CT and the larger engines run wet sleeves.

Tell us the engine model and whether you need standard or oversize, and if the bores have already been machined, the size they were taken out to.

Products in this category

12 listed

Open one for its specification and the part numbers it covers. We stock more than we list, so send us the number even if yours isn’t here. You can also look a number up in the part number index.