Technical Specifications: Specifications: Pistons

WARNING: This page is about a different car, the 2019 Fiat 500X. However, it is still accessible from the selected car via links, so may be relevant.

PISTONS

Description	Specification
Description	Metric	Standard
Material	Cast Aluminum Alloy
Piston Diameter - Class A*	69.935 - 66.945 mm	2.7533 - 2.6356 in.
Piston Diameter - Class B*	69.945 - 66.955 mm	2.7537 - 2.6360 in.
Piston Diameter - Class C*	69.955 - 66.965 mm	2.7541 - 2.6364 in.
Clearance at Size Location	0.055 - 0.075 mm	0.0022 - 0.0030 in.
Piston Pin Bore	18.004 - 18.009 mm	0.7088 - 0.7090 in.
Piston Ring Groove Width - No. 1	1.220 - 1.250 mm	0.0480 - 0.0492 in.
Piston Ring Groove Width - No. 2	1.220 - 1.240 mm	0.0480 - 0.0488 in.
Piston Ring Groove Width - No. 3	2.010 - 2.030 mm	0.0791 - 0.0799 in.
*Measured perpendicular to piston pin bore, 7 mm (0.28 in.) from base of piston skirt

PISTON PINS

Description	Specification
Description	Metric	Standard
Type	Floating
Pin Diameter	18.000 - 17.950 mm	0.7087 - 0.7067 in.

PISTON RING END GAP

Description	Specification
Description	Metric	Standard
Number 1 Ring (Top)	0.180 - 0.280 mm	0.0071 - 0.0110 in.
Number 2 Ring (Center)	0.400 - 0.600 mm	0.0157 - 0.0236 in.
Oil Control Ring (Bottom)	0.200 - 0.900 mm	0.0079 - 0.0354 in.

PISTON RING SIDE CLEARANCE

Description	Specification
Description	Metric	Standard
Number 1 Ring (Top)	0.030 - 0.080 mm	0.0012 - 0.0031 in.
Number 2 Ring (Center)	0.025 - 0.070 mm	0.0010 - 0.0028 in.
Oil Control Ring (Bottom)	0.100 - 0.136 mm	0.0040 - 0.0054 in.

PISTON RING WIDTH

Description	Specification
Description	Metric	Standard
Number 1 Ring (Top)	1.170 - 1.190 mm	0.0461 - 0.0469 in.
Number 2 Ring (Center)	1.170 - 1.195 mm	0.0461 - 0.0470 in.
Oil Control Ring (Bottom)	1.894 - 2.000 mm	0.0746 - 0.0787 in.