Detroit Diesel 4-71 engine specs at Barrington Diesel Club

Barrington Diesel club provides Detroit Diesel engine specs and technical Data

Detroit Diesel 4-71 engine specs are to be found at Barrington Diesel Club, whose aim it is to provide technical data, specs and bolt torques relevant to Cummins, Detroit Diesel, EMD and ADE engines.
At Barrington diesel club bolt tightening torques and fuel consumption rates are provided for many engines beginning with Detroit Diesel,Cummins, and ADE. Our Web Log provides a forum for discussing diesel engine features and problems. We also provide general technical data such as Standard Torques for bolts and nuts, Properties of materials like the melting and boiling points of metals, metric to imperial cross references, SAE Flywheel housing sizes, as well as providing articles of general interest like discussions on fuel consumption and Detroit Diesel Air Box Pressures.

View Terms & Conditions

Detroit Diesel 4-71 Power ratings
Detroit Diesel 4-71 Power at sea level (Industrial Engines)
rpm	1200	1400	1600	1800	2000	2100
Horse Power SAE	91	110	124	136	149	155
Power Kw	68	82	92	101	111	116
.	.	.	.	.	.	.
Torque Ft lbs	398	413	407	397	391	388
Torque Nm	540	560	552	438	531	526
.	.	.	.	.	.	.
Fuel Consumption	15	17	19	20	22	23
.	.	.	.	.	.	.
Max Toque Ft lbs	413 @ 1400 rpm
Max Torque Nm	560 @ 1400 rpm

Detroit Diesel 4-71 Power ratings

Detroit Diesel 4-71 Power at sea level (Industrial Engines)

rpm

1200

1400

1600

1800

2000

2100

Horse Power SAE

110

124

136

149

155

Power Kw

101

111

116

Torque Ft lbs

398

413

407

397

391

388

Torque Nm

540

560

552

438

531

526

Fuel Consumption

Max Toque Ft lbs

413 @ 1400 rpm

Max Torque Nm

560 @ 1400 rpm

Physical Characteristics Detroit Diesel 4-71N
Weight	1776 lbs	807 kgs
Length	42"	1067 mm
Width	29"	737 mm
Height	41"	1041 mm
Compression Ratio	18.7:1
Displacement	284Cu Inches	4,654 ml
Bore	4.250 inches	107.95 mm
Stroke	5.00 inches	127.00 mm

Physical Characteristics Detroit Diesel 4-71N

Weight

1776 lbs

807 kgs

Length

42"

1067 mm

Width

29"

737 mm

Height

41"

1041 mm

Compression Ratio

18.7:1

Displacement

284Cu Inches

4,654 ml

Bore

4.250 inches

107.95 mm

Stroke

5.00 inches

127.00 mm

Selected torque specifications Detroit Diesel 4-71N Engine
Torques (Non standard)	Bolt Size	Ft Lbs	Nm
Air box cover	3/8 NC	15	20
Con Rod bolts / Big Ends	7/16 NF	67	90
Cam and Balance-shaft nuts	1 1/8 NF	300	407
Cam follower guide bolts	¼NC	15	20
* Crank end bolt	1" NF	290	393
* Cylinder Head	5/8 NC	184	250
Flywheel Housing Bolts	1/2 NC	95	130
Fuel Connectors	7/16 NF	35	45
Fuel Line Nuts	3/8 NF	15	20
Idler gear hub bolts	3/8 NC	40	54
Injector clamp bolts	3/8 NC	25	34
* Mains	5/8 NC	184	250
Rocker shaft bolts	1/2 NC	96	130
Sump bolts	5/16 NC	10	14
* Flywheel bolts	9/16 NF	184	250
.	.	.	.
*	Lubricate with 'International Compound No 2, or Copper-Slip' or equivalent.

Selected torque specifications Detroit Diesel 4-71N Engine

Torques (Non standard)

Bolt Size

Ft Lbs

Air box cover

3/8 NC

Con Rod bolts / Big Ends

7/16 NF

Cam and Balance-shaft nuts

1 1/8 NF

300

407

Cam follower guide bolts

¼NC

* Crank end bolt

1" NF

290

393

* Cylinder Head

5/8 NC

184

250

Flywheel Housing Bolts

1/2 NC

130

Fuel Connectors

7/16 NF

Fuel Line Nuts

3/8 NF

Idler gear hub bolts

3/8 NC

Injector clamp bolts

3/8 NC

* Mains

5/8 NC

184

250

Rocker shaft bolts

1/2 NC

130

Sump bolts

5/16 NC

* Flywheel bolts

9/16 NF

184

250

Lubricate with 'International Compound No 2, or Copper-Slip' or equivalent.

71 Series Pistons

On Cross-Head pistons - Torquing con rod to piston/gudgeon pin

Caution - Failure of piston pin retainer bolts is always catastrophic, often a hole in the block - it happened on two occasions to me while dyna-testing engines
Suggestion - Apply locktite (or equivalent thread lock compound) to the 7/16 NF bolts
torque to 60 lb-ft, 80 Nm; do not exceed torque

Installing piston/gudgeon pin retainer plates

Caution - Leaking retainer plates are only remedied by extensive rework, i.e. head and sump at least must be removed again.
Suggestion - Apply shellac (or equivalent compound) to rim of retainer plates
Rap retainer plate into place with a domed/rounded object of similar size to the plate. (small machined nylon rod is ideal)
Allow shellac to dry (overnight)
Test piston plate seal by pouring power-paraffin or diesel into the inverted piston, the outside of the plate must remain completely dry, let it stand for a few minutes before using it to make sure.

Selected Settings Detroit Diesel 4-71N
Set	Inches	mm
Injectors (N60)	1.460	37.10
Injectors (N65 brown tag)	1.484	37.69
Valves (4v head -cold)	0.016	0.41
Valves (2v head -cold)	0.012	0.30

Selected Settings Detroit Diesel 4-71N

Set

Inches

Injectors (N60)

1.460

37.10

Injectors (N65 brown tag)

1.484

37.69

Valves (4v head -cold)

0.016

0.41

Valves (2v head -cold)

0.012

0.30

Selected Standard Sizes and useful clearances Detroit Diesel 4-71N
Part	Min inches	Max inches	Limits ins	Min mm	Max mm	Limits mm
Con Rod - ID Small End Bush	1.5025	1.5030	1.5080	38.1635	38.1762	38.3032
Con Rod - Length center to center	10.1240	10.1260	.	257.1496	257.2004	.
Crankshaft end float	0.0040	0.0160	.	0.10	0.41	.
Crankshaft Big end Std Diameter	2.7490	2.7500	.	69.8246	69.8500	.
Crankshaft Mains Std Diameter	3.4990	3.5000	.	88.8746	88.9000	.
Cyl liner - flange below block	0.0450	0.0500	0.0500	1.1430	1.2700	.
Cyl Liner - flange below block variation	0.0000	0.0020	.	0.00	0.05	.
Cyl Liner - ID	4.2495	4.2511	.	107.9373	107.9779	.
Cyl Liner - OD Std	4.6250	4.6260	.	117.4750	117.5004	.
Piston skirt diameter	4.2428	4.2450	.	107.7671	107.8230	.
Ring gap - compression rings	0.0180	0.0430	0.0600	0.4572	1.0922	1.5200
Ring gap - oil rings	0.0050	0.0140	0.0340	0.1270	0.3556	0.8636

Selected Standard Sizes and useful clearances Detroit Diesel 4-71N

Part

Min inches

Max inches

Limits ins

Min mm

Max mm

Limits mm

Con Rod - ID Small End Bush

1.5025

1.5030

1.5080

38.1635

38.1762

38.3032

Con Rod - Length center to center

10.1240

10.1260

257.1496

257.2004

Crankshaft end float

0.0040

0.0160

0.10

0.41

Crankshaft Big end Std Diameter

2.7490

2.7500

69.8246

69.8500

Crankshaft Mains Std Diameter

3.4990

3.5000

88.8746

88.9000

Cyl liner - flange below block

0.0450

0.0500

1.1430

1.2700

Cyl Liner - flange below block variation

0.0000

0.0020

0.00

0.05

Cyl Liner - ID

4.2495

4.2511

107.9373

107.9779

Cyl Liner - OD Std

4.6250

4.6260

117.4750

117.5004

Piston skirt diameter

4.2428

4.2450

107.7671

107.8230

Ring gap - compression rings

0.0180

0.0430

0.0600

0.4572

1.0922

1.5200

Ring gap - oil rings

0.0050

0.0140

0.0340

0.1270

0.3556

0.8636

Selected Tune up & useful information 4-71N Detroit Diesel engines
Item	Condition
Altitude deration	2.5% for every 300 m or 1000 ft
Cooling System - engine capacity	4.40 litres
Cooling System - radiator capacity	8.80 litres
Firing Order	1-3-4-2
Oil consumption	normal 60 to 120 ml per hour
Oil pan capacity	average 14 litres, full mark 50 mm below sump top
Speed full load max	Most common at 2100 rpm
Speed no load max	Most common at 2275 rpm
Speed at idle	commonly at 680 rpm

Selected Tune up & useful information 4-71N Detroit Diesel engines

Item

Condition

Altitude deration

2.5% for every 300 m or 1000 ft

Cooling System - engine capacity

4.40 litres

Cooling System - radiator capacity

8.80 litres

Firing Order

1-3-4-2

Oil consumption

normal 60 to 120 ml per hour

Oil pan capacity

average 14 litres, full mark 50 mm below sump top

Speed full load max

Most common at 2100 rpm

Speed no load max

Most common at 2275 rpm

Speed at idle

commonly at 680 rpm

Operating Conditions 4-71N series engines
Item	Condition
Compression (sea level)	New parts - average 39 bar
Compression (sea level)	New parts - min 35 bar @ 600 rpm
Fuel Pressure @ 1500 rpm	3 bar
Oil Pressure - normal operation	3.5 bar
Oil Pressure - idle	0.8 bar
Oil Temperature - sump	90-113°C
Water Temperature	77-91°C

Operating Conditions 4-71N series engines

Item

Condition

Compression (sea level)

New parts - average 39 bar

Compression (sea level)

New parts - min 35 bar @ 600 rpm

Fuel Pressure @ 1500 rpm

3 bar

Oil Pressure - normal operation

3.5 bar

Oil Pressure - idle

0.8 bar

Oil Temperature - sump

90-113°C

Water Temperature

77-91°C

Full Load expected Air Box Pressures for Detroit Diesel engines
Indicated in inches and mm of mercury
rpm	1800	2000	2100
Naturally aspirated N engines	1", 25 mm	4", 100 mm	5", 125 mm
Turbo engines	22", 594 mm	28", 756 mm	30", 810 mm
TI engines	27", 686 mm	32", 864 mm	35", 945 mm
Notes: Measuring Air Box Pressure Connect a manometer to one air box drain. Measure pressure at fixed RPM's The above table gives an indication of what to expect, but air box pressures vary with altitude and from engine to engine, injector to injector, turbo to turbo; so take nothing as definitive. If your air box pressures are close to the values listed in the table there is normally no problem in this area. If you're at all concerned, contact the local agents with your model and serial number for further advice.

Full Load expected Air Box Pressures for Detroit Diesel engines

Indicated in inches and mm of mercury

rpm

1800

2000

2100

Naturally aspirated N engines

1", 25 mm

4", 100 mm

5", 125 mm

Turbo engines

22", 594 mm

28", 756 mm

30", 810 mm

TI engines

27", 686 mm

32", 864 mm

35", 945 mm

Notes: Measuring Air Box Pressure

Connect a manometer to one air box drain. Measure pressure at fixed RPM's
The above table gives an indication of what to expect, but air box pressures vary with altitude and from engine to engine, injector to injector, turbo to turbo; so take nothing as definitive.
If your air box pressures are close to the values listed in the table there is normally no problem in this area.
If you're at all concerned, contact the local agents with your model and serial number for further advice.

Detroit Diesel 4-71 engine specs at Barrington Diesel Club

Barrington Diesel club provides Detroit Diesel engine specs and technical Data

Specs for 4-71 Detroit Diesel engines and technical data provided courtesy of Barrington Diesel Club

71 Series Pistons

On Cross-Head pistons - Torquing con rod to piston/gudgeon pin

Installing piston/gudgeon pin retainer plates