L26 Specs – Datsun 260Z Engine Specifications

Here are all of the verified engine statistics from the Datsun 260Z factory service manual for the L26.

Some of the links on ZCarGuide page may be affiliate links, meaning I receive a commission (at no extra cost to you) if you click on the link and make a purchase. I only recommend products I’ve used and trust unless stated otherwise. 

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)