Description

Nissan A10, A12 Service Manual – Factory Service Data on Your Bench

If you’re diving into an old Datsun with an A10 or A12 four-cylinder, reaching for a generic Chilton or Haynes is a mistake. Those books condense and skip – and that’s how you end up with a warped head or a thrown rod. The Nissan A10, A12 Service Manual is the actual factory document Nissan Motor Co. issued to its dealers in 1973. 154 pages of engineering data that came straight from the Tokio plant. No condensation, no aftermarket interpretation. You get the same specs a Nissan master tech had on his bench forty years ago.

This manual is written in Spanish – the original language for the Latin American market – but torque values and clearances are universal. You’ll find the exact oil capacity, valve lash, and ignition timing for both the A10 and A12. Page 4 lists the principal specifications: displacement, compression ratio, firing order. That’s where you start before you turn a single bolt.

Engine Tune-Up: Puesta a Punto del Motor ET

You’ll want to open to the ET section before you pull a distributor. The factory procedure for setting ignition timing and idle speed is laid out stepwise, with the tools required listed right there. No assuming you can eyeball it – Nissan wanted a dwell meter and a tachometer on the bench. The manual tells you which vacuum hose to plug, which screw to turn, and what the final reading should be in degrees BTDC. Do it by the book and you won’t be chasing a stumble later.

7 Systems Covered from Block to Alternator

The table of contents breaks the A10 and A12 into seven logical systems:

• EG – Generalidades sobre el motor (engine general information)
• ET – Puesta a punto del motor (engine tune-up)
• EM – Parte mecánica del motor (engine mechanical)
• EL – Sistema de lubricación del motor (engine lubrication)
• CO – Sistema de enfriamiento (cooling system)
• EF – Sistema de combustible (fuel system)
• EE – Sistema eléctrico del motor (engine electrical)

That last section – EE – covers the alternator, starter, and ignition wiring. If you’ve ever wrestled with an aftermarket wiring diagram that doesn’t match your car’s harness, you’ll appreciate having the factory schematic. Every connector, every wire color, every ground point is drawn the way Nissan intended. Page 5 shows the external engine views with component callouts, so you can identify each part before you start disassembly.

Does This Manual Include Torque Values and Clearances?

It does – and they’re the ones Nissan specified, not a third-party guess. The EG section on page 4 gives the main bearing bore size, piston pin diameter, and oil pressure at operating temperature. The EM section (parte mecánica del motor) goes into the head bolt tightening sequence and torque. These engines have a cast-iron block and an aluminum head, and the torque procedure must be followed in stages. Skip a step and you risk a head gasket failure inside 500 miles. This manual lists the exact order and the final ft-lbs – no rounding up.

Original OEM Print vs. Aftermarket Reproductions

Aftermarket manuals often combine multiple model years into one book, which means they drop the 1972 emissions control system details or the 1973 revised compression ratio. This manual is specific to the A10 and A12 series motors built through February 1973. The preface explicitly states that all information is based on product data available at that date. It also references the separate emission control manual for 1972 models. That level of detail is what you lose when you buy a reprint. You get the original factory layout, with the same pagination and illustrations that Nissan approved.

Who Needs This Manual?

You do, if you own a Datsun 1200, Datsun 100A, or any other vehicle that used the A10 or A12 engine. Home garage enthusiasts will find the periodic inspection checklist on page 6 (Mantenimiento e inspección periódicos) invaluable – it tells you what to check at every 1,000 miles, from valve clearance to drive belt tension. Professional mechanics working on vintage Japanese cars will save diagnostic time by having the factory wiring logic right in front of them. And if you’re restoring a car to showroom condition, you need the original specs to get the engine running exactly as it did when it left the line.

Trust the factory data. One paragraph: No shortcuts.

For related vehicle service data, explore the Nissan A10 and A12 Engine Service Manual for the full chassis information. If you work on later Nissan models, the Nissan Xterra 2005 Service Manual – OEM Factory Spec covers a different engine family, and the Nissan 60 1967 Service Manual – Original Factory Bulletin is another period-correct document. For a wider view of how factory manuals differ from aftermarket, see Automotive Industry Overview and also Automotive Industry Overview.

Frequently Asked Questions

Is this manual in English?

No. The manual is published in Spanish, the original language for Nissan’s Latin American distribution.

What engine years and models does it cover?

The manual covers the A10 and A12 engines used in Datsun vehicles up to February 1973. It was prepared to help dealer service personnel maintain and repair these motors in the Datsun 1200 and Datsun 100A. The preface warns that specifications may change after that date, so if your engine has a serial number later than early 1973, you should also consult the factory service bulletins. The manual references the separate emission control system manual for 1972 models. For complete vehicle details, it directs you to the DATSUN 1200 Service Manual, which describes the chassis, body, and transmission. This engine manual focuses exclusively on the A10 and A12 power units, giving you all the internal specifications, torque values, and system diagrams needed for a full overhaul or tune-up.

Stop wasting time on reprinted junk. Click the link above to access the Factory Manual – your A10 or A12 engine deserves the original specs.