3.9 V8i Engine — Tuning Data (Discovery 1)

Type - V8i 3.9 l

The firing order of the cylinders is 1-8-4-3-6-5-7-2

Cylinder numbers

• Left half block - 1-3-5-7
• Right half block - 2-4-6-8

Cylinder numbering - from the crankshaft pulley

The installation marks are on the torsional vibration damper

Spark plugs

Manufacturer/Type (compression ratio 8.13:1) — Champion RN11YCC

Gap: 0.84-0.96 mm

Manufacturer/Type (compression ratio 9.35:1) — Champion RN11 YCC

Gap: 0.84-0.96 mm

Ignition coil

Manufacturer / type - Bosch 0-221-122-392,

Compression ratio: 8.13:1 or 9.35:1

Fuel injection system - Lucas 14 CUX with air flow sensor (hot filament anemometer) and electronic control unit

Valve timing	inlet	release
It's opening	32° before TDC	70° before BDC
It's closing	73° after BDC	35° after TDC
Duration	285°	285°
Maximum valve lift	104° after TDC	114° before TDC

Idle speed (under the control of the MFI system)

All additional loads are turned off - 665 - 735 rpm

Automatic transmission in position D, air conditioning ON — 650±28 rpm

Automatic transmission in position D, air conditioning OFF — 600±28 rpm

Manual transmission - 700 ±28 rpm

Manual transmission, air conditioning on — 750

(The original article is located on: «LRMAN.RU»)

The idle speed setting is 525±25 rpm

Ignition timing - dynamic at 800 rpm, vacuum regulator disconnected

Compression ratio 8.13:1, without neutralizer - 2° before TDC ±10

Compression ratio 9.35:1, without neutralizer - 4° before TDC ±1°

Compression ratio 9.35:1, with neutralizer - 5° before TDC ±1°

Exhaust gases

CO concentration: 0.5-1.0% max.

Distributor

Manufacturer: Lucas 35DLM8

Rotation - clockwise

Air gap: 0.20-0.35 mm

Number	Lucas	Rover
8.13:1, without neutralizer	42584A	ERR 4753
9.35:1, without neutralizer	42582A	ERR 4754
9.35:1, with neutralizer	42583A	ERR 4755

Centrifugal ignition timing regulator

Check - Disconnect the vacuum hose

8.13:1 without neutralizer

• 2000 - change in advance from 5°30' to 8°30'
• 1400 – from 6°18' to 8°30'
• 800 — from 2° to 4°

9.35:1 without neutralizer

• 2200 - change in advance from 7° to 10°
• 1400 — from 7°48' to 10°
• 650 — from 1° to 3°

9.35:1 with neutralizer

• 2200 - change in advance from 5°30' to 8°30'
• 1400 – from 6°18' to 8°30'
• 800 — from 2° to 4°

Fuel (unleaded gasoline)

• 8.13:1, without neutralizer - AI-91 or higher
• 9.35:1, without neutralizer - AI-95 or higher
• 9.35:1, with neutralizer - AI-95 or higher

Models for Australia

Fuel - AI-91 or higher, unleaded

Compression ratio: 8.13:1

Spark plug — Champion RN12YC

Gap: 0.84-0.96 mm

Ignition timing at 800 rpm (the vacuum hose is disconnected) — 2° before TDC ±1°

CO concentration - 1% max.