Piston rings

Make

Alfa Romeo

Model

155 Factory Service Manual

Year

1992–1998

Section

Rod - piston assembly › Piston rings

Engine – mechanical (V6)Piston rings

	MONDIAL	BORGO
Piston diameter (a) (1)	A - Blue	87.925 ÷ 87.935	87.935 ÷ 87.945
	B - Pink	87.935 ÷ 87.945	87.945 ÷ 87.955
	C - Green	87.945 ÷ 87.955	87.955 ÷ 87.965
Height of first seal ring seating (b)	1.525 ÷ 1.545
Height of second seal ring seating (c)	1.525 ÷ 1.545
Height of oil scraper ring seating (d)	3.515 ÷ 3.535
Diameter of gudgeon pin hole in (e)	Black	22.003 ÷ 22.006
	White	22.006 ÷ 22.009
Clearance between cylinder liner and piston	0.040 ÷ 0.059
Weight difference between pistons	± 2 g

(1) To be measured perpendicular to the gudgeon pin hole at a distance of f = 12 mm from the lower edge of skirt.

Piston rings

	First ring	1.475 ÷ 1.490
Thickness of rings (a)	second ring	1.475 ÷ 1.490
	oil scraper ring	3.475 ÷ 3.490
Ring gap (1) (b)	First ring	0.30 ÷ 0.50
	second ring	0.30 ÷ 0.50
	oil scraper ring	0.30 ÷ 0.50 (2)
		0.25 ÷ 0.50 (3)
Axial play between piston rings and seatings	First ring	0.035 ÷ 0.070
	second ring	0.035 ÷ 0.070
	oil scraper ring	0.025 ÷ 0.055

(1) To be measured in the checking ring nut or in the cylinder liner

(2) Borgo

(3) Goetze

07 Engine