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Ford LSG-423 Engine

General Technical Data

Engine Specifications

Engine Model ............... Ford LSG-423
Engine Configuration ............... 4-Cycle Inline 4-Cylinder Overhead Camshaft
Number of Cylinders ............... 4
Cylinder Arrangement ............... In-line Vertical
Engine Bore, in (mm) ............... 3.780 (96.0)
Engine Stroke, in (mm) ............... 3.126 (79.4)
Total Displacement, cu.in (L) ............... 140 (2.3)
Rated Engine Power, hp (kW) ............... 63 (47) at 4000 rpm
Intermittent Maximum Torque, lb-ft (Nm) ............... 115 (156) at 2400 rpm
Compression Ratio ............... 9.0:1
Firing Order ............... 1-3-4-2
Direction of Crankshaft Rotation ............... Clockwise from Front View
Direction of Distributor Rotation ............... Clockwise from Top View
Cylinder Block Material ............... Cast Iron
Cylinder Head Material ............... Cast Iron
Valvetrain Layout ............... Single Overhead Camshaft SOHC
Number of Valves per Cylinder ............... 2
Combustion Chamber Type ............... Fast-Burn Wedge Chamber
Main Bearing Journals ............... 5 Premium Replaceable Inserts
Camshaft Drive Mechanism ............... Cogged Timing Belt System
Piston Material ............... Autothermic Aluminum Alloy with Steel Struts
Crankshaft Material ............... Precision Cast Nodular Iron
Connecting Rod Material ............... Forged Carbon Steel
Crankcase Ventilation System ............... Positive PCV Valve with Closed Loop Breather
Cylinder Head Gasket Material ............... Perforated Steel Core with Compressed Fiber Facings
Crankshaft Front Seal Config ............... Synthetic Rubber Radial Lip Seal with Garter Spring
Crankshaft Rear Main Seal Config ............... One-Piece Molded Elastomeric Lip Seal
Intake Manifold Design ............... Water-Heated Cast Aluminum Cross-Flow System
Exhaust Manifold Design ............... High-Silicon Ductile Iron Free-Flow Log Design
Lubrication System ............... Full-pressure
Oil Pump Type ............... Rotor type, gear-driven
Oil Filter Type ............... Full-flow, spin-on
Cooling System ............... Liquid-cooled
Water Pump Type ............... Belt-driven, centrifugal
Air Cleaner Type ............... Dry dual-stage
Starting System ............... Electric Starter
Electrical System ............... 12V
Alternator Output ............... 40-60A

Fuel System

Fuel Type Capability ............... Gasoline or Liquefied Petroleum Gas LPG or Natural Gas NG
Carburetor Model Config ............... Single Barrel Downdraft with Manual or Electric Choke
LPG Carburetor Type ............... Venturi Type Diaphragm Air-Valve Mixer
Fuel Lift Pump Type ............... Mechanical Diaphragm Eccentric-Driven from Auxiliary Shaft
Fuel Pump Static Pressure Range, psi (kPa) ............... 4.0-6.0 (27.6-41.4)
Fuel Pump Volume Delivery Minimum ............... 1.0 pt (0.47 L) within 30 sec at Idle Speed
Maximum Inlet Pressure to LPG Regulator, psi (kPa) ............... 250 (1724)
LPG Regulator Secondary Stage Lock-off Pressure, in H2O (kPa) ............... 0.5 (0.12)
Fuel Filter System ............... In-line Spin-on Element or Carburetor Inlet Screen
Governor System Type ............... Electronic Governor Hoof or Barber-Colman Actuator System
Governor High Idle Target Speed, rpm ............... 2150-2500
Governor Low Idle Target Speed, rpm ............... 1400-1600
Carburetor Base Standard Low Idle Speed, rpm ............... 900
Air-Fuel Ratio Range for Gasoline Combustion ............... 14.7:1 nominal
Air-Fuel Ratio Range for LPG Combustion ............... 15.5:1 nominal
Throttle Plate Operation Diameter, in (mm) ............... 1.50 (38.1)
Choke Plate Default Position ............... Normally Open Spring-Loaded to Cold-Start Rich Position
Fuel Lines Material Specs ............... High-Pressure Reinforced Nitrile Rubber SAE J30R7
LPG Vaporizer Primary Stage Heat Source ............... Engine Liquid Coolant Jacket Loop
Main Fuel Jet Orifice Diameter Gasoline, in (mm) ............... 0.052 (1.32)
Idle Fuel Jet Orifice Diameter Gasoline, in (mm) ............... 0.024 (0.61)

Dimensions and Weight

Overall Length, in (mm) ............... 37.0 (940)
Overall Width, in (mm) ............... 25.0 (635)
Overall Height, in (mm) ............... 36.0 (914)
Dry Weight, lbs (kg) ............... 467 (212)
Shipping Weight, lbs (kg) ............... 515 (234)

Maintenance Data

Service Information

Compression Range at Cranking Speed, psi (kPa) ............... 150.0-180.0 (1034.2-1241.1)
Minimum Oil Pressure at 2000 rpm, psi (kPa) ............... 40.0-60.0 (275.8-413.7)
Minimum Oil Pressure at 900 rpm, psi (kPa) ............... 15.0 (103.4)
Thermostat Opening Start Temperature, F (C) ............... 190 (87.7)
Thermostat Full Open Temperature, F (C) ............... 210 (98.9)
Cooling System Cap Pressure, psi (kPa) ............... 13.0-15.0 (89.6-103.4)
Spark Plug Type ............... Motorcraft AWSF-42 or Equivalent Standard Plugs
Spark Plug Gap, in (mm) ............... 0.034 (0.86)
Ignition Timing at Low Idle, deg BTDC ............... 6-10
Breaker Point Gap, in (mm) ............... 0.025 (0.635)

Engine Oil and Coolant

Engine Oil Type .................. SAE 10W-40, SAE 20W-40
API Service Classifications ......................... SG/CC
Lubrication System Capacity with Filter, qt (L) ............... 5.0 (4.7)
Lubrication System Capacity without Filter, qt (L) ............... 4.0 (3.8)
Cooling System Capacity (Engine Only), qt (L) ............... 3.5 (3.3)

Service Intervals

Change engine oil ............... Every 100 hours
Replace oil filter ............... Every 100 hours
Replace fuel filter ............... Every 400 hours
Inspect air filter ............... Every 100 hours
Replace air filter ............... Every 400 hours
Change coolant ............... Every 1000 hours
Valve-lash adjustment ............... Every 400 hours
Check fuel system ............... Every 800 hours
Replace spark plug ............... Every 800 hours
Compression test ............... Every 800 hours
Belt inspection ............... Every 100 hours

Service Specifications

Cylinder Bore Inside Diameter, in (mm) ............... 3.7800-3.7808 (96.012-96.032)
Cylinder Bore Out-of-Round Maximum, in (mm) ............... 0.0010 (0.0254)
Cylinder Bore Taper Maximum, in (mm) ............... 0.0010 (0.0254)
Cylinder Bore Maximum Wear Llimit, in (mm) ............... 3.7850 (96.139)
Main Bearing Journal Diameter, in (mm) ............... 2.3990-2.3998 (60.935-60.955)
Main Bearing Journal Out-of-Round, in (mm) ............... 0.0003 (0.0076)
Main Bearing Oil Clearance, in (mm) ............... 0.0008-0.0015 (0.0203-0.0381)
Crankshaft End Play, in (mm) ............... 0.0040-0.0080 (0.1016-0.2032)
Crankpin Journal Diameter, in (mm) ............... 2.0465-2.0473 (51.981-52.001)
Connecting Rod Bearing Oil Clearance, in (mm) ............... 0.0008-0.0015 (0.0203-0.0381)
Connecting Rod Side Clearance, in (mm) ............... 0.0035-0.0105 (0.0889-0.2667)
Piston Skirt to Cylinder Bore Clearance, in (mm) ............... 0.0014-0.0022 (0.0356-0.0559)
Piston Pin Bore Inside Diameter, in (mm) ............... 0.9122-0.9126 (23.170-23.180)
Piston Pin Outer Diameter, in (mm) ............... 0.9118-0.9120 (23.160-23.165)
Piston Pin to Piston Pin Bore Clearance, in (mm) ............... 0.0003-0.0005 (0.0076-0.0127)
Piston Pin to Con Rod Bushing Clearance, in (mm) ............... 0.0003-0.0007 (0.0076-0.0178)
Top Ring Groove Width, in (mm) ............... 0.0805-0.0825 (2.045-2.096)
Second Ring Groove Width, in (mm) ............... 0.0805-0.0825 (2.045-2.096)
Oil Ring Groove Width, in (mm) ............... 0.1885-0.1895 (4.788-4.813)
Top Ring Side Clearance, in (mm) ............... 0.0020-0.0040 (0.0508-0.1016)
Second Ring Side Clearance, in (mm) ............... 0.0020-0.0040 (0.0508-0.1016)
Oil Ring Side Clearance, in (mm) ............... 0.0015-0.0035 (0.0381-0.0889)
Top Ring End Gap, in (mm) ............... 0.0110-0.0210 (0.2794-0.5334)
Second Ring End Gap, in (mm) ............... 0.0110-0.0210 (0.2794-0.5334)
Oil Ring End Gap, in (mm) ............... 0.0150-0.0550 (0.3810-1.3970)
Cylinder Head Gasket Surface Flatness ............... 0.003 (0.0762)
Intake Valve Stem Outside Diameter, in (mm) ............... 0.3416-0.3423 (8.677-8.694)
Exhaust Valve Stem Outside Diameter, in (mm) ............... 0.3411-0.3418 (8.664-8.682)
Intake Valve Guide Inside Diameter, in (mm) ............... 0.3433-0.3443 (8.720-8.745)
Exhaust Valve Guide Inside Diameter, in (mm) ............... 0.3433-0.3443 (8.720-8.745)
Intake Valve Stem to Guide Clearance, in (mm) ............... 0.0010-0.0027 (0.0254-0.0686)
Exhaust Valve Stem to Guide Clearance, in (mm) ............... 0.0015-0.0032 (0.0381-0.0813)
Valve Face Angle, deg ............... 44.5
Valve Seat Angle, deg ............... 45.0
Intake Valve Seat Width, in (mm) ............... 0.060-0.080 (1.524-2.032)
Exhaust Valve Seat Widtht, in (mm) ............... 0.070-0.090 (1.778-2.286)
Valve Spring Free Length, in (mm) ............... 1.910 (48.514)
Camshaft Journal Diameter (Front), in (mm) ............... 1.7610-1.7620 (44.729-44.755)
Camshaft Journal Diameter (Middle), in (mm) ............... 1.7760-1.7770 (45.110-45.136)
Camshaft Journal Diameter (Rear), in (mm) ............... 1.7910-1.7920 (45.491-45.517)
Camshaft Journal to Head Bore Clearance, in (mm) ............... 0.0010-0.0030 (0.0254-0.0762)
Camshaft Journal Bearing Wear Limit, in (mm) ............... 0.0050 (0.1270)
Camshaft Axial End Play, in (mm) ............... 0.0010-0.0070 (0.0254-0.1778)
Cam Lobe Lift (Intake), in (mm) ............... 0.2380 (6.0452)
Cam Lobe Lift (Exhaust), in (mm) ............... 0.2490 (6.3246)
Valve Tappet Lash Bore Inside Diameter, in (mm) ............... 0.8430-0.8449 (21.412-21.460)
Valve Tappet Lash Outside Diameter, in (mm) ............... 0.8417-0.8423 (21.379-21.394)
Valve Tappet to Valve Lash Bore Clearance, in (mm) ............... 0.0007-0.0032 (0.0178-0.0813)
Auxiliary Shaft Journal Diameter (Front), in (mm) ............... 1.7610-1.7620 (44.729-44.755)
Auxiliary Shaft Journal Diameter (Rear), in (mm) ............... 1.7610-1.7620 (44.729-44.755)
Auxiliary Shaft Journal to Block Bearing Clearance, in (mm) ............... 0.0010-0.0030 (0.0254-0.0762)

Tightening Torques

Cylinder Head Fasteners (Step 1), lb-ft (Nm) ............... 50-60 (67.8-81.3)
Cylinder Head Fasteners (Step 2), lb-ft (Nm) ............... 80-90 (108.5-122.0)
Main Bearing Cap Fasteners, lb-ft (Nm) ............... 75-85 (101.7-115.2)
Connecting Rod Cap Fasteners, lb-ft (Nm) ............... 30-36 (40.7-48.8)
Crankshaft Pulley Damper Center Bolt, lb-ft (Nm) ............... 100-120 (135.6-162.7)
Camshaft Sprocket Gear Attachment Bolt, lb-ft (Nm) ............... 50-65 (67.8-88.1)
Auxiliary Shaft Sprocket Attachment Bolt Torque, lb-ft (Nm) ............... 50-65 (67.8-88.1)
Timing Belt Tensioner Spring Adjustment Locking Bolt, lb-ft (Nm) ............... 28-40 (38.0-54.2)
Timing Belt Tensioner Spring Pivot Support Bolt, lb-ft (Nm) ............... 28-40 (38.0-54.2)
Flywheel to Crankshaft Attachment Fasteners, lb-ft (Nm) ............... 56-64 (75.9-86.8)
Oil Pan Basin Peripheral Drain Plug Bolt, lb-ft (Nm) ............... 15-25 (20.3-33.9)
Oil Pan Basin to Cylinder Block Attaching Bolts, lb-ft (Nm) ............... 10-13.5 (13.6-18.3)
Oil Pump Assembly Housing to Cylinder Block Bolts, lb-ft (Nm) ............... 14-21 (19.0-28.5)
Oil Pump Pickup Tube Support Strap to Block Bolt, lb-ft (Nm) ............... 14-21 (19.0-28.5)
Oil Pump Pick-up Screen Tube Flange to Pump Bolts, lb-ft (Nm) ............... 7-10 (9.5-13.6)
Valve Rocker Arm Mechanism Top Metal Cover Screws, lb-ft (Nm) ............... 6-9 (8.1-12.2)
Water Pump Housing to Cylinder Block Fasteners, lb-ft (Nm) ............... 14-21 (19.0-28.5)
Water Pump Driven Pulley Face Attaching Bolts, lb-ft (Nm) ............... 15-22 (20.3-29.8)
Intake Manifold Plenum to Cylinder Head Attaching Bolts, lb-ft (Nm) ............... 15-22 (20.3-29.8)
Exhaust Manifold Casting to Cylinder Head Attaching Nuts, lb-ft (Nm) ............... 12-15 (16.3-20.3)
Cylinder Block Front Cover Die Cast Shell Plate Bolts, lb-ft (Nm) ............... 6-9 (8.1-12.2)
Timing Belt Outer Thermoplastic Protection Shroud Screws, lb-ft (Nm) ............... 6-9 (8.1-12.2)
Spark Plug Sockets Threaded Cylinder Head Base, lb-ft (Nm) ............... 15-22 (20.3-29.8)
Distributor Base Clamping Bracket Tie-down Screw, lb-ft (Nm) ............... 14-21 (19.0-28.5)
Distributor Cap Plastic Housing Retention Fasteners, lb-ft (Nm) ............... 2.0-3.0 (2.7-4.1)
Fuel Lift Pump Housing to Cylinder Block Mount Fasteners, lb-ft (Nm) ............... 14-21 (19.0-28.5)
Carburetor Base Mounting Flange Nuts to Manifold Studs, lb-ft (Nm) ............... 12-15 (16.3-20.3)
Alternator Housing Pivot Adjustment Slider Fastener Bolt, lb-ft (Nm) ............... 25-35 (33.9-47.5)
Alternator Mounting Bracket Frame to Engine Block Bolts, lb-ft (Nm) ............... 35-50 (47.5-67.8)
Starter Motor Housing Nose Flange to Flywheel Housing, lb-ft (Nm) ............... 15-20 (20.3-27.1)
Thermostat Housing Water Outlet Flange Screws, lb-ft (Nm) ............... 14-21 (19.0-28.5)
Oil Pressure Sensor Sending Switch Hex Base Fitting, lb-ft (Nm) ............... 12-18 (16.3-24.4)
Coolant Temperature Sensor Switch Base Fitting, lb-ft (Nm) ............... 12-18 (16.3-24.4)
Crankcase Rear Main Oil Seal Retainer Plate Screws, lb-ft (Nm) ............... 6-9 (8.1-12.2)
Flywheel Housing Bellhousing Interface Engine Bolts, lb-ft (Nm) ............... 40-55 (54.2-74.6)
Engine Support Insulator Engine Mount Frame Bolts, lb-ft (Nm) ............... 45-65 (61.0-88.1)

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• Ford Engines Specs
  
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• Ford LRG-423 Specs
  

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