Fitting Instructions – Prestige Parts® UE46310 Piston Set

Prestige Parts® UE46310 Pistons are manufactured from a superior method of piston design involving a hypereutectic forging technique. Hypereutectic forging provides a stronger base material than that possible in cast pistons. UE46310 Pistons are of a short skirt design to reduce instances of bottom skirt seizure, noise, and to reduce weight. They are supplied with rings of the highest standard, that have been quality approved using the latest optical and tangential testing techniques. 

When fitting these pistons, care must be taken to follow the fitting instructions provided here. All other fitting instructions provided by the vehicle manufacturer’s workshop manual should be followed carefully. 

Bore Size

These pistons require a working clearance of 0.004” (0.09 mm). Ideally Liners of the correct grade should be fitted at the same time (product reference UE71222X). Failure to observe the working clearance may result in engine failure. 

Piston Orientation

The gudgeon pin is slightly offset to ensure the piston “kicks” parallel to the piston liner, so it must be fitted the correct way round.

Identifying, orienting & gapping compression rings

Centre and Top compression rings are different and may be identified as follows: Centre compression rings are chamfered on the lower inner edge and must be fitted the correct way up. The top of the Centre ring is indicated by a small impression next to the ring gap:  

Top rings are symmetrical and may be fitted either way up. 

All compression rings should be gapped to 0.012-0.020” (0.30-0.51 mm).