12-valve engine (Mazda Capella GD)

Cylinder head

Cylinder head height	91.95-92.05 mm
Permissible warpage of the cylinder head surface	0.15 mm
Permissible warping of the nozzle surface	0.10 mm
Max, additional processing of the cylinder head surface	0.20 mm
Valve seat angle	45°

Valves

Valve disc diameter:
— inlet valve	32.4-32.6 mm
- exhaust valve	33.9-34.1 mm
Valve length:
— inlet valve	115.81 mm (min. 115.31 mm)
- exhaust valve	116.21 mm (min. 115.71 mm)
Valve stem diameter:
— inlet valve	6,970-6,985 mm
- exhaust valve	6,965-6,980 mm
Operating clearance of valve stems in guides:
— inlet valve	0.025-0.060 mm
- exhaust valve	0.030-0.065 mm
Max. working clearance of valve stems in guides	0.20 mm
Valve edge thickness:
— inlet valve	0.8-1.2 mm
- exhaust valve	1.3-1.7 mm
Wear limit	1.0 mm
Valve guides:
Inner diameter	7.01-7.03 mm
Cylinder head installation temperature	80—100°C
Installation size of guides	19.8-20.3 mm

Valve springs

Free length:
— inlet valve	49.5 mm (min. length 49.0 mm)
- exhaust valve	50.4 mm (min. length 43.7 mm)
Permissible warping on the upper side	1.8 mm
Installation length:
— inlet valve	41.0 mm at 20.7-23.4 kg
- exhaust valve	41.0 mm at 24.5–27.7 kg
Valve seats
Valve seat angle	45°
Valve seat width	1.2-1.6 mm
Valve seat depth	measure the protruding length of the valve stems

Camshaft

Axial clearance of the camshaft	0.08-0.16 mm
Max axial clearance	0.20 mm
Max camshaft deflection	0.03 mm
Camshaft Bearing Clearance:
— front bearing (No. 1)	0.035-0.085 mm
— middle bearings (No. 2, 3, 4)	0.65-0.115 mm
— rear bearing (No. 5)	0.035-0.085 mm
— wear limit, all bearings 0.15 mm
Bearing journal diameter:
- front bearing	31,940-31,965 mm
- medium bearings	31,910-31,935 mm
- rear bearing	31.940-31.965 mm
- wear limit	less than 0.05 mm
Height of projection:
— inlet valve	41.140 mm, wear limit
- exhaust valve	41.647 mm, wear limit

Rocker arm mechanism

Inner diameter of rocker arm	19,000-19,033 mm
Rocker shaft diameter	18,959-18,980 mm
Rocker arm working clearance	0.020-0.074 mm
- wear limit	0.10 mm

Valve timing

Opening the intake valves	14° before top dead center
Closing the intake valves	56° after bottom dead center
Opening the exhaust valves	69° before bottom dead center
Closing the exhaust valves	13° after top dead center

Pistons, piston pins, piston rings

Piston rings	2 piston rings, oil scraper piston ring
Piston pins	press fit
Piston diameter	85.944-85.964 mm
— permissible deviations	0.25 and 0.50 mm
Piston working clearance:
— nominal size	0.036-0.075 mm
- wear limit	0.15 mm
Piston ring tappet clearance:
- upper ring	0.20-0.35 mm
- middle ring	0.15-0.30 mm
— oil scraper ring	0.20-0.70 mm
- wear limit	1.00 mm
Maximum ring clearance in piston groove:
- upper ring	0.030-0.070 mm
- middle ring	0.030-0.070 mm
- wear limit	0.15 mm
Piston ring thickness:
- upper ring	1.47-1.49 mm
- the second ring	1.47-1.49 mm
Permissible deviation of piston ring	as for the piston

(The article is based on website data: MAZbook.ru)

Piston pins

Diameter	21,974—21,980
Shrink fit in the connecting rod	0.013-0.037 mm
Working clearance in pistons	0.008-0.024 mm
Setting pressure	500-1500 kg
Working clearance in the lower connecting rod bushings	the pistons should move with a little effort, but without any gap

Connecting rods

Length, center to center	151.95-152.05 mm
Connecting rod head bore	21,943–21,961 mm
Permissible twisting and bending	0.06 mm per 100 mm of length
Axial clearance on the crankshaft journals	0.11-0.26 mm
- wear limit	0.30 mm
Connecting rod bearing working clearance	0.027-0.067 mm
- wear limit	0.10 mm
Permissible deviation in the bearing shell	0,25; 0.50 and 0.75 mm

Crankshaft

Number of main bearings	5
Perception of axial pressure	through flanged liners on the middle bearing
Main/connecting rod bearing design	thin-walled bearing shells
Crankshaft axial clearance	0.03-0.18 mm
- wear limit	0.30 mm
Radial (working) clearance of the main bearing:
— nominal clearance, except for bearing No. 3	0.025-0.043 mm
— nominal clearance, bearing No. 3	0.031-0.049 mm
- wear limit	0.08 mm
Radial (working) clearance of connecting rod bearing:
— nominal clearance	0.027-0.067 mm
- wear limit	0.10 mm
Main bearing journal diameter:
— nominal diameter	59.937-59.955 mm
- wear limit	0.05 mm
— finishing boundary	0.75 mm
Max, constriction or quality	0.05 mm
Max crankshaft bending	0.03 mm
Permissible deviation of bearing shells	0,25; 0.50 and 0.75 mm
Crankshaft journal diameter:
— nominal diameter	50.940-50.955 mm
- wear limit	0.05 mm
Polishing border	0.75 mm
Max, constriction or quality	0.05 mm
Permissible deviation of bearing shells	0,25; 0.50 and 0.75 mm
Max flywheel surface runout	0.10 mm

Cylinder block

Cylinder block height	289.0 mm
Max. sealing surface warpage	0.15 mm
Max, finishing polishing	0.20 mm
Cylinder bores	86,000–86,019 mm
Deviations of holes	0.25 and 0.50 mm
Max. hole wear	0.15 mm
Max, constriction and ovality	0.02 mm
Piston working clearance	0.036-0.075 mm
Place for measuring the bearing diameter	18.0 mm below the ring groove in the right corner relative to the piston pins