Description

Nissan L13, L16, L20 Service Manual – OEM Factory Specs for the L-Series Engine

You have an L13, L16, or L20 on the stand and the aftermarket manual you grabbed gave you the wrong ring gap and didn’t list the valve adjustment sequence. I’ve seen that mistake cost a shop a full day of rework. What you need is the factory Nissan L13, L16, L20 Service Manual—186 pages of original specifications that came out of Nissan’s own engineering department. No third-party rewrites, no missing torque values, no guesswork. This is the same binder your dealer’s lead tech would pull from the shelf in 1969.

Nissan L13, L16, L20 Service Manual: 186 Pages of Factory Data

Every page in this manual was printed by Nissan Motor Co., Ltd., Tokyo, Japan. The quick reference index lists nine sections: Engine General (EG), Engine Tune-Up (ET), Engine Mechanical (EN), Engine Lubrication System (EL), Cooling System (CO), Fuel System (EF), Emission Control System (EC), Engine Electrical System (EE), and Service Equipment (SE). That is the full scope of the engine—nothing missing, nothing added. Page EG-5 contains the main specifications for all three displacements, so you get the bore, stroke, compression ratio, and the factory torque sequence for the cylinder head. If you are rebuilding an L20, you need those numbers verbatim, not an approximation from a forum post.

7 Engine Systems Covered in This Manual

• Engine General – External views, serial number locations, lubricant and coolant specs
• Engine Tune-Up – Ignition timing, valve clearance, idle speed adjustments
• Engine Mechanical – Disassembly, inspection, reassembly of the block, head, and valvetrain
• Engine Lubrication System – Oil pump specs, oil pressure checks, sump details
• Cooling System – Water pump, thermostat, radiator flow data
• Fuel System – Carburetor adjustments, fuel pump testing, line routing
• Electrical System – Starting and charging circuits, wiring diagrams, distributor specs

Each section is built around step-by-step repair procedures with specific torque callouts and required tool lists. The Emission Control chapter covers the early PCV and air injection systems that can make a vintage L-series run rough if hooked up wrong. Do not skip that section just because you think it is not relevant—the factory engineers put it there for a reason.

What Torque Values Are Listed?

The manual gives exact ft-lb values for the cylinder head bolts, main bearing caps, connecting rods, and flywheel. It also includes the tightening sequence and angle-of-turn data where applicable. For example, the L20 head bolt sequence is different from the L16 because of the taller deck height. The specs are on page EG-5 under Main Specifications. If you are using an aftermarket torque chart, you are gambling with your head gasket. This manual takes that risk off the table.

Cooling System: Factory Flow and Cap Data

The CO section includes thermostat opening temperature, water pump flow rates, and the correct radiator cap pressure rating. It also shows the coolant routing so you can confirm you did not swap the inlet and outlet hoses. A lot of guys think any 13-lb cap works. Nissan specified a specific pressure for the L-series because the core was thinner on early radiators. The manual spells that out.

Fuel System and Electrical Diagnostics

The EF chapter covers the Hitachi carburetors used on these engines—float level, jet sizes, and mixture screw settings. The Electrical section (EE) has complete wiring diagrams for the ignition switch, alternator, and starter circuit. If you are chasing a no-spark condition on an L16, the manual walks you through the continuity checks in the correct order, using the tool setup they designed the harness around. Related manuals worth having on your shelf: Nissan Xterra 2005 Service Manual – OEM Factory Spec, Nissan 60 1967 Service Manual – Original Factory Bulletin, and Nissan L60, L60-U, KL60-U 1968 Service Manual – Factory Specs.

Why OEM Documentation Beats Aftermarket Versions

I have been doing this 28 years. Aftermarket manuals often copy the factory drawings but leave out the footnotes that change the torque sequence for a cast-iron head versus an aluminum one. This manual is the original print. You get the same warnings, the same inspection criteria, and the same tolerances that Nissan sent to its own dealerships. The automotive industry operates on these standards, not on summaries. For broader reference, see Automotive Industry Overview and Automotive Industry Overview for how manufacturers structure service documentation.

Frequently Asked Questions

Does this manual cover the L20B variant?

It covers the L20 as listed in the title, not the L20B which came later with a different block and head.

Can I use this for a full car service on a Datsun 510 or 2000?

The foreword on page 3 states this manual covers only the engine and must be used alongside the Datsun 510 Service Manual and Datsun 2000 Service Manual for complete vehicle details. If you are working on a 510, you will need both manuals because the transmission, suspension, and body wiring are not included here. The fuel system chapter covers the engine-side components only—the tank and lines are in the chassis manual.

Stop chasing half-correct data from online forums. Get the actual factory print that every serious Nissan L-series builder relies on. Access the Factory Manual and have the full 186 pages on your tablet or printed for the bench.