ENGINE
70
OVERHAUL Piston rings - checking
CAUTION: Prior to checking piston ring
gaps in cylinder bores, bores must be
inspected, measured and if reboring has
been carried out, the appropriate oversize
pistons and rings used.
1.Check fitted gap of each new piston ring in turn
with ring positioned half-way down cylinder
bore.
Fitted gap of rings in bores:
Top compression = 0.40 to 0.65 mm
2nd compression = 0.30 to 0.50 mm
Oil control rails = 0.30 to 0.60 mm
CAUTION: Ensure that piston rings are
suitably identified with the cylinder bore in
which they were checked and that they are
fitted to the piston for that cylinder bore.
2.Fit oil control rails and spring to piston.
3.Fit 2nd, narrow compression ring with 'TOP'
marking uppermost.
4.Fit top compression ring with 'TOP' marking
uppermost.
5.Check that rings are free to rotate in their
grooves.
