BHM1169 RING SET.  Standard size 2⁷/₈” bore (73mm) piston rings set for Nuffield 4/25 and Leyland 154 tractors.  

This ring set is made up from: 1 x 12H249 Top ring, 2 x 12H250 2nd and 3rd rings and 2 x 12H251 Oil ring.

Fitted to:

• Leyland 154
• Nuffield 4/25
• BMC 1500cc diesel engine
• Thornycroft 90 Boat/Marine engine

IMPORTANT NOTE
When fitting piston rings the ring gaps should always be checked prior to fitting to the piston as follows:

PISTON RING GAP FITTED IN THE BORE
No. 1 compression ring – 0.012 inch to 0.020 inch (0.30 mm to 0.51 mm)
No. 2 and No. 3 compression rings – 0.008 inch to 0.013 inch (0.20 mm to 0.33 mm)
No. 4 and No. 5 oil control rings – 0.008 inch to 0.013 inch (0.20 mm to 0.33 mm)

Note: Big end bolts torque – 35 lbs/ft (4.85 kg/m)