Piston Rings; End Gap; Replacement - Acura 3.5 RL Manual

Piston Rings

End Gap

1. Using a piston, push a new ring into the cylinder
bore 15-20 mm (0.6 - 0.8 in) from the bottom.
2. Measure the piston ring end-gap with a feeler
gauge:
• If the gap is too small, check to see if you have the
proper rings for your engine.
• If the gap is too large, recheck the cylinder bore
diameter against the wear limits on page 7-15.
If the bore is over the service limit, the cylinder
block must be rebored.
Piston Ring End-Gap:
Top Ring
Standard (New): 0.25 - 0.40 mm
(0.010 - 0.016 in)
Service Limit: 0.70 mm (0.028 in)
Second Ring
Standard (New): 0.40 - 0.55 mm
(0.016 - 0.022 in)
Service Limit: 0.85 mm (0.033 in)
Oil Ring
Standard (New): 0.20 - 0.70 mm
(0.008 - 0.028 in) *1
0.20 - 0.50 mm
(0.008 - 0.020 in) *2
Service Limit: 0.80 mm (0.031 in)
PISTON RING
END GAP
*1: RIKEN manufactured piston ring.
*2: TEIKOKU PISTON RING manufactured piston ring.
15 - 20 mm
(0.6-0.8 in)

Replacement

1. Using a ring expander, remove the old piston rings.
2. Clean all the ring grooves thoroughly.
NOTE:
• Use a squared-off broken ring or ring groove
cleaner with a blade to fit the piston grooves. File
down the blade if necessary.
• Top ring groove is 1.5 mm (0.06 in) wide, the
second ring groove is 1.2 mm (0.05 in) wide, and
the oil ring groove is 2.8 mm (0.11 in) wide.
CAUTION: Do not use a wire brush to clean the ring
grooves, or cut ring grooves deeper with the clean-
ing tool.
NOTE: If the piston is to be separated from the con-
necting rod, do not install new rings yet.
3. Install new rings in the proper sequence and posi-
tion (see pages 7-21,
NOTE: Do not reuse old piston rings.
PISTON RING
RING EXPANDER
(Commercially available)
7-22).