Here are all of the verified engine statistics from the Datsun 260Z factory service manual for the L26.
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General specifications
- Engine code number: L26
- Engine type: Six cylinder (in-line), single overhead camshaft (SOHC)
- Displacement: 156.6cubic in (2565 cc)
- Bore: 3.27 in (83 mm)
- Stroke: 3.11 in (79 mm)
- Maximum brake horsepower: 165@ 5600 revolutions/minute (rpm)
- Maximum gross torque (lb./ft.): 157 @ 4400 revolutions/minute (rpm)
- Compression ratio: 8.3:1 (98 oct)
- Oil pressure (hot at 2000 rpm): 50-57 lb/(in squared) or 3.5-4.0 kg/(cm squared)
- Engine oil (sump): 8.2 lmp pints (4.7 liters / 9.9 U.S. pints)
Crankshaft
- Journal diameter: 2.1631-2.1636 in (54.942-54.955 mm)
- Maximum taper or ovality of journal: 0.0004 in (0.01 mm)
- Maximum endfloat: 0.0118 in (0.3 mm)
- Crankpin diameter: 1.9670-1.9675 in (49.961-49.974 mm)
- Maximum taper and ovality or crankpin: 0.0118 in (0.3mm)
- Main bearing thickness: 0.0717-0.0722 in (1.822-1.835 mm)
- Main bearing running clearance: 0.0008-0.0028 in (0.020-0.072 mm)
- Running clearance (wear limit): 0.0047 in (0.12 mm)
Camshaft
- Journal diameter: 1.8878-1.8883 in (47.949-47.962 mm)
- Bearing inside diameter: 1.8898-1.8904 in (48.000-48.016 mm)
- Running clearance: 0.0015-0.0026 in (0.038-0.067 mm)
- Camshaft endfloat: 0.0031-0.0150 in (0.08-0.38 mm)
- Camshaft lobe lift: 0.2756 in (7.00 mm)
Pistons
- Standard diameter: 3.267-3.269 in (82.985-83.035 mm)
- Oversizes for L24 engine:
- First: 3.276-3.278 in (83.22-83.27 mm)
- Second: 3.286-3.288 in (83.47-83.52 mm)
- Third: 3.296-3.298 in (83.72-83.77 mm)
- Fourth: 3.305-3.308 in (83.97-84.02 mm)
- Fifth: 3.326-3.328 in (84.47-84.52 mm)
- Piston to bore clearance: 0.0010-0.0018 in (0.025-0.045 mm)
- Piston ring groove width
- Top compression: 0.079 in (2.0 mm)
- Second compression: 0.079 in (2.0 mm)
- Oil control: 0.0157 in (4.0 mm)
Piston Rings
- Thickness
- Top compression: 0.0778 in (1.977 mm)
- Second compression: 0.0778 in (1.977 mm)
- Ring end gap
- Top compression: 0.0091-0.0150 in (0.23-0.38 mm)
- Second compression: 0.0059-0.0118 in (0.15-0.30 mm)
- Clearance in groove
- Top compression: 0.0018-0.0031 in (0.045-0.080 mm)
- Second compression: 0.0012-0.0028 in (0.030-0.070 mm)
Gudgeon pins
- Diameter: 0.8265-0.8267 in (20.933-20.998 mm)
- Length: 2.8346-2.8445 in (72.00-72.25 mm)
- Clearance (gudgeon pin to piston): 0.0002-0.0051 in (0.006-0.013 mm)
- Interference fit in connecting rod small end: 0.0006-0.0013 in (0.015-0.033 mm)
Connecting rods
- Distance between centers: 5.237 in (133.08 mm)
- Bearing thickness (big-end): 0.0588-0.0593 in (1.493-1.506 mm)
- Big-end running clearance: 0.0010-0.0022 in (0.025-.055 mm)
- Big-end endfloat: 0.006-0.0013 in (0.015-0.033 mm)
Valves
- Clearance (hot)
- Inlet: 0.010 in (0.25 mm)
- Exhaust: 0.012 in (0.30 mm)
- Clearance (cold)
- Inlet: 0.008 in (0.20 mm)
- Exhaust: 0.010 in (0.25 mm)
- Valve head diameter
- Inlet: 1.65 in (42.0 mm)
- Exhaust: 1.38 in (35.0 mm)
- Valve stem diameter
- Inlet: 0.3136-0.3142 in (7.965-7.980 mm)
- Exhaust 0.3128-0.3134 in (7.945-7.960 mm)
- Valve length
- Inlet: 4.524-4.535 in. (114.9-115.2 mm)
- Exhaust 4.555-4.567 in (115.7-116.0 mm)
- Valve lift: 0.433 in (11.0 mm)
- Spring free length
- Outer: 1.968 in (49.98 mm)
- Inner: 1.766 in (44.85 mm)
- Spring coil diameter
- Outer: 1.307 in (33.2 mm)
- Inner: 0.980 in (24.9 mm)
- Guide length: 2.323 in (59.0 mm)
- Guide inside diameter: 0.3150-0.3157 in (8.000-8.018 mm)
- Guide outside diameter (standard): 0.4733-0.4738 (12.023-12.034 mm)
- Guide to stem clearance
- Inlet: 0.0008-0.0021 in (0.020-0.053 mm)
- Exhaust: 0.0016-0.0029 in (0.040-0.073 mm)
- Seat width
- Inlet: 0.055-0.063 in (1.4-1.6 mm)
- Exhaust: 0.071-0.087 in (1.8-2.2 mm)
- Seat angle: 45 degrees
Torque Wrench Guidelines
- Cylinder head bolts
- Stage 1: 29 lb-ft (4.0 kg-m)
- Stage 2: 40 lb-ft (5.5 kg-m)
- Stage 3: 60 lb-ft (8.3 kg-m)
- Big-end bolts: 30 lb-ft (4.1 kg-m)
- Flywheel bolts: 100 lb-ft (13.8 kg-m)
- Main bearing cap bolts: 40 lb-ft (5.5 kg-m)
- Camshaft sprocket bolt: 40 lb-ft (5.5 kg-m)
- Sump bolts: 7 lb-ft (0.9 kg-m)
- Oil pump bolts: 11 lb-ft (1.5 kg-m)
- Rocker pivot locknuts: 40 lb-ft (5.5 kg-m)
- Camshaft locating plate bolts: 6 lb-ft (0.8 kg-m)
- Manifold nuts: 8 lb-ft (1.1 kg-m)
- Fuel pump nuts: 13 lb-ft (1.8 kg-m)
- Crankshaft pulley bolt: 100 lb-ft (13.8 kg-m)
- Front cover bolts
- Large: 11 lb-ft (1.5 kg-m)
- Small: 5 lb-ft (0.7 kg-m)
- Air pump mounting bolts: 18 lb-ft (2.5 kg-m)
- Air pump adjustment strap bolt: 13 lb-ft (1.8 kg-m)
- Clutch bellhousing to engine bolts: 36 lb-ft (4.9 kg-m)
- Torque converter housing to engine bolts: 36 lb-ft (4.9 kg-m)
- Driveplate to torque converter: 36 lb-ft (4.9 kg-m)
- Driveplate to crankshaft: 100 lb-ft (13.8 kg-m)
- Propeller shaft flange to pinion flange bolts: 23 lb-ft (3.2 kg-m)
- Exhaust downpipe flange nuts: 18 lb-ft (2.5 kg-m)