Specifications

4M41 ENGINE -

Crank Shaft and Crank Case

11B-25-8

4. CYLINDER BORING

(1) Determine the oversize piston to be used based on the

largest cylinder inside diameter.

(2) There are two types of oversize pistons available (+0.50

mm a nd +1.00 mm). Bore the cylinders so that the

clearance between the cylinder an d the piston installed

meets the specified standard value. The reference point

for piston O.D. measurement is as shown.

Standard value: 0.04 - 0.05 mm

(3) Based on the measured piston outside diameter, calculate

the necessary boring dimension as follows.

D Boring dimension = Piston O.D. + 0.04 to 0.05 mm

(piston-to-cylinder clearance) - 0.05 mm (honing

allowance)

(4) Grind each cylinder to the calculated boring dimension.

Caution

1. Because of the hardened cylinder layer, the use

of a BORAZON TIP is recommended.

2. To avoid thermal distortion, bore the cylinders

in the order of No. 2, No. 4, No. 1 and No. 3.

(5) Hone each cylinder to the final bore (piston O.D. +

piston-to-cylinder clearance).

NOTE

(1) Honed surface roughness: 2 to 4 mm

(2) Honing crosshatch angle: 15 to 25_ (half angle)

(3) Cylinder bore out-of-squareness: 0.05 mm

(6) Check that the piston-to-cylinder clearance is within the

specified standard value range.

Standard value: 0.04 - 0.05 mm

PWEE9409-D

Feb. 2000Mitsubishi Motors Corporation Added

53.5 mm