Detroit Diesel Series 71

Series 71
Overview
Manufacturer Detroit Diesel
Production 1938–1995
Layout
Configuration multi-cylinder, inline and vee
Displacement 71 cu in (1,160 cc) (per cylinder)
Cylinder bore 4.250 in (108.0 mm)
Piston stroke 5.000 in (127.0 mm)
Compression ratio 18.7:1 (N/A)
17:1 (Turbo)
Chronology
Successor Series 60

The Detroit Diesel Series 71 is a two-stroke diesel engine series, available in both inline and V configurations. The first number in the model series designation refers to the number of cylinders, and the second - 71 - the nominal displacement per cylinder in cubic inches, a rounding off of 70.93 cu in (1,162.3 cc).

Inline models included one, two, three, four and six cylinders, and the V-types six, eight, 12, 16 and 24 cylinders.

The two largest V units used multiple cylinder heads per bank to keep the head size and weight to manageable proportions, the V-16 using four heads from the four-cylinder inline model and the V-24 using four heads from the inline six-cylinder model. This feature also assisted in keeping down the overall cost of these large engines by maintaining parts commonality with the smaller models.

History

The inline six-cylinder 71 series engine was introduced as the initial flagship product of the Detroit Diesel Engine Division of General Motors in 1938. The V-type first appeared in 1957.

The 71 Series went off of the market in the summer of 1995, and the four stroke Detroit Diesel engine was introduced as a replacement.

Design

Bore and stroke are the same across all units, at 4.25 in × 5.00 in (108 mm × 127 mm). Inline models were famously "symmetrical", meaning that blower, exhaust, water manifold, starter, and other components could be mounted on either side of the basic block to fit a particular application. A number of models could also run with the crankshaft turning either clockwise or counter-clockwise, called "Right Hand" or "Left Hand" rotation engines (as viewed from the front of the engine). The less-common Left Hand engines were typically used in buses and boats because that engine rotation matched with an rear-engined transversal installation in buses and respectively the propeller rotation.

As a two-stroke diesel engine that does not use crankcase aspiration cannot naturally draw in combustion air, the blower is inherently necessary to charge the cylinders with air for combustion. The blower also assists in scavenging spent combustion gasses at the end of the power stroke. All Series 71 engines use uniflow scavenging, in which a gear-driven Roots blower mounted to the exterior of the engine provides intake air through cored passages in the engine block and ports in the cylinder walls at slightly greater than atmospheric pressure. The engine exhausts through pushrod-operated poppet valves in the cylinder head(s), with either two or four valves per cylinder. Unit fuel injection is employed, one injector per cylinder, with no high fuel pressure outside of the injector body. The injectors are cycled from the same camshaft responsible for opening the exhaust valves.

Nomenclature

The first number refers to the number of cylinders in the engine, followed by a dash ("-") or "V", indicating an inline block or a vee-block, respectively, and then 71 for the Series designation. The 71 in the model series designation refers to the nominal displacement per cylinder in cubic inches, a rounding off of 70.93 cu in (1,162.3 cc).

The suffix denotes additional engine features. Engines fitted only with a blower are referred to as "naturally aspirated" (SAE designation) and have an N suffix in the model designation, e.g., 8V-71N is a V-8 "naturally aspirated" Series 71 engine. Later high-performance versions were available with turbochargers, and turbochargers with intercooling, the turbochargers discharging into the Roots blower intake. Such engines have a T suffix in the model designation, e.g., 8V-71T.

Model Codes
TTurbocharged
VV-Block configuration
LLow profile
N4 exhaust valves (per cylinder)

Applications

Motor Coach Industries MC-9 bus powered by a rear-mounted 8V-71 Detroit Diesel engine.

The most popular incarnations of the series 71 engine as used for highway vehicle applications included the inline 6-71, the V-block 6V-71 (both widely used in transit buses) and the 8V-71 V-8. In addition to motorcoach propulsion, both inline and V types have found extensive usage in trucks, fire apparatus, motor homes, construction and industrial machinery, a few farm tractors, commercial fishing vessels, and military vehicles and equipment.

The 71 series is very popular in marine applications, not only as a propulsion engine in small craft (Gray Marine 6-71) but as auxiliary power to drive generators, winches and other heavy shipboard machinery. The Detroit inline 6-71 engine, in all of its variations, was also available as a 'pancake engine' (here variably called either 6L-71 or 6N-71) for horizontal (underfloor) mount applications, such as on larger Crown and Gillig school buses and articulated puller transit buses (such as the Crown-Ikarus 286).

71 series variants

ModelDisplacementEngine configurationHorsepower
1-711.2L (71ci)Single-cylinder10
2-712.3L (142ci)I-268
3-713.5L (213ci)I-3113
4-714.7L (284ci)I-4160
6-717.0L (426ci)I-6238
6V-717.0L (426ci)V-6238
8V-719.3L (568ci)V-8318
12V-7114.0L (852ci)V-12450
16V-7118.6L (1136ci)V-16635
24V-7127.9L (1704ci)V-241800
Series 71 specifications for selected models
FamilyModelTorquePowerLength × Width × HeightWeight
3-71 3-71[1] 299 ft⋅lbf (405 N⋅m)
@ 1400 RPM		 109 hp (81 kW)
@ 2100 RPM		 36 in × 29 in × 41 in
910 mm × 740 mm × 1,040 mm		 1,525 lb
692 kg
4-71 4-71[1][2] 385–400 ft⋅lbf (522–542 N⋅m)
@ 1600 RPM		 140–152 hp (104–113 kW)
@ 2100 RPM		 42 in × 29 in × 42 in
1,070 mm × 740 mm × 1,070 mm		 1,780 lb
810 kg
4-71T[3] 525 ft⋅lbf (712 N⋅m)
@ 1400 RPM		 190 hp (140 kW)
@ 2100 RPM		 44 in × 31 in × 44 in
1,120 mm × 790 mm × 1,120 mm		 1,830 lb
830 kg
6-71 6-71[1][4] 600–612 ft⋅lbf (813–830 N⋅m)
@ 1600 RPM		 218–228 hp (163–170 kW)
@ 2100 RPM		 54 in × 29 in × 39 in
1,370 mm × 740 mm × 990 mm		 2,190 lb
990 kg
6-71T[3][5] 762–801 ft⋅lbf (1,033–1,086 N⋅m)
@ 1400 RPM		 275–285 hp (205–213 kW)
@ 2100 RPM		 56 in × 32 in × 50 in
1,420 mm × 810 mm × 1,270 mm		 2,195–2,240 lb
996–1,016 kg
6-71TT[6] 853 ft⋅lbf (1,157 N⋅m)
@ 1200 RPM		 230 hp (170 kW)
@ 1950 RPM		 56 in × 32 in × 52 in
1,420 mm × 810 mm × 1,320 mm		 2,195 lb
996 kg
6V-71 6V-71[7][8] 600 ft⋅lbf (810 N⋅m)
@ 1600 RPM		 228 hp (170 kW)
@ 2100 RPM		 41 in × 39 in × 48 in
1,040 mm × 990 mm × 1,220 mm		 2,380 lb
1,080 kg
6V-71T[8] 725 ft⋅lbf (983 N⋅m)
@ 1600 RPM		 262 hp (195 kW)
@ 2100 RPM		 41 in × 40 in × 53 in
1,000 mm × 1,000 mm × 1,300 mm		 2,380 lb
1,080 kg
8V-71 8V-71[7][9] 800 ft⋅lbf (1,100 N⋅m)
@ 1600 RPM		 304 hp (227 kW)
@ 2100 RPM		 47 in × 39 in × 51 in
1,190 mm × 990 mm × 1,300 mm		 2,900 lb
1,300 kg
8V-71T[9] 965 ft⋅lbf (1,308 N⋅m)
@ 1600 RPM		 350 hp (260 kW)
@ 2100 RPM		 50 in × 40 in × 53 in
1,300 mm × 1,000 mm × 1,300 mm		 2,495 lb
1,132 kg
8V-71TA[10] 1,064 ft⋅lbf (1,443 N⋅m)
@ 1200 RPM		 360 hp (270 kW)
@ 2100 RPM		 50 in × 40 in × 53 in
1,300 mm × 1,000 mm × 1,300 mm		 2,415 lb
1,095 kg
8V-71TTA[10]> 1,064 ft⋅lbf (1,443 N⋅m)
@ 1600 RPM		 305 hp (227 kW)
@ 2100 RPM		 43 in × 38 in × 49 in
1,090 mm × 970 mm × 1,240 mm		 2,415 lb
1,095 kg
12V-71 12V-71[7][11] 1,200 ft⋅lbf (1,600 N⋅m)
@ 1600 RPM		 456 hp (340 kW)
@ 2100 RPM		 60 in × 46 in × 58 in
1,500 mm × 1,200 mm × 1,500 mm		 3,210 lb
1,460 kg
12V-71T[11] 1,450 ft⋅lbf (1,970 N⋅m)
@ 1600 RPM		 525 hp (391 kW)
@ 2100 RPM		 70 in × 46 in × 55 in
1,800 mm × 1,200 mm × 1,400 mm		 3,550 lb
1,610 kg
16V-71 16V-71TI[12] 2,150 ft⋅lbf (2,920 N⋅m)
@ 1600 RPM		 800 hp (600 kW)
@ 2100 RPM		 79 in × 47 in × 59 in
2,000 mm × 1,200 mm × 1,500 mm		 4,820 lb
2,190 kg

Further developments

WWII General Motors 6004/6046 engine

The inline 6-71 was adapted to British requirements as the power plant for Canadian (and later British) built Valentine tanks where it was known as the GMC 6004, orders being placed in late September 1940.[13]

The 6046 Diesel was a twin engine setup used by US and British tanks and tank destroyers.

Detroit diesel 6051 quad-71

The Detroit diesel 6051 quad-71 was a Detroit Diesel Series 6-71 side by side tandem engine setup of two banks of four engines each driving two propeller shafts in Landing Craft Infantry LCI(L). The eight engines produced a total of 1600BHP.[14]

Soviet/Russian copies

In the Soviet Union / Russia, various versions of this engine-type were produced at the Yaroslavl automobile factory (YaAZ).[15] Throughout World War II, the 4-71 engine both in locally assembled form (built by Lend-Lease provided American industrial equipment) and from USA-supplied kits had been used for Ya-12 light artillery tractors[16] and trucks. After 1945, the 4-71 engine entered production in a slightly modified configuration to suit the conditions of the Soviet Union branded "YaAZ-204".[15] After 1947 the factory used a copy of the 6-71 engine branded "YaAZ-206" in the YaAZ 200 / 210 / 214 series of heavy trucks built from 1947 to 1960. Production was transferred to KrAZ in Kremenchug, Ukraine in 1959, where newer versions of the YaAZ-206 stood in production until the appearance of the four-stroke V8-engined KrAZ-255 in 1967.[17][18][19][20][21]

See also

References

  1. 1 2 3 "fan-to-flywheel models: 3-71, 4-71, & 6-71" (PDF). Detroit Diesel Engines. Retrieved 17 July 2018.
  2. ↑ "fan-to-flywheel models: 4-71" (PDF). Detroit Diesel Engines. Retrieved 17 July 2018.
  3. 1 2 "fan-to-flywheel models: 4-71T & 6-71T" (PDF). Detroit Diesel Engines. Retrieved 17 July 2018.
  4. ↑ "fan-to-flywheel models: 6-71" (PDF). Detroit Diesel Engines. Retrieved 17 July 2018.
  5. ↑ "truck models: 6-71T" (PDF). Detroit Diesel Engines. Retrieved 17 July 2018.
  6. ↑ "truck models: 6-71TT" (PDF). Detroit Diesel Engines. Retrieved 17 July 2018.
  7. 1 2 3 "fan-to-flywheel models: 6V-71, 8V-71, & 12V-71" (PDF). Detroit Diesel Engines. Retrieved 17 July 2018.
  8. 1 2 "fan-to-flywheel models: 6V-71 & 6V-71T" (PDF). Detroit Diesel Engines. Retrieved 17 July 2018.
  9. 1 2 "fan-to-flywheel models: 8V-71 & 8V-71T" (PDF). Detroit Diesel Engines. Retrieved 17 July 2018.
  10. 1 2 "8V-71TA & 8V-71TTA" (PDF). Detroit Diesel Engines. Retrieved 17 July 2018.
  11. 1 2 "fan-to-flywheel models: 12V-71 & 12V-71T" (PDF). Detroit Diesel Engines. Retrieved 17 July 2018.
  12. ↑ "fan-to-flywheel models: 16V-71TI" (PDF). Detroit Diesel Engines. Retrieved 17 July 2018.
  13. ↑ Engines used by British vehicles
  14. ↑ http://www.ibiblio.org/hyperwar/USN/ref/ONI/ONI-226/ONI-226.pdf
  15. 1 2 "YaAz-204 Diesel engine" (in Russian). русская-сила.рф. Retrieved 2013-11-21.
  16. ↑ "Engines of the Red Army in WW2 - Artillery Tractor Ya-12". Engines of the Red Army in WW2. 2007-03-12. Retrieved 2013-11-22.
  17. ↑ Andrei Bogomolov. "Oldtimer picture gallery. Trucks. YaAZ". Retrieved 2013-11-20.
  18. ↑ Andrei Bogomolov. "Oldtimer gallery. Trucks. YaAZ-210". Retrieved 2013-11-20.
  19. ↑ "KrAZ-219". OldRussianCars.com. 2013-07-21. Retrieved 2013-11-20.
  20. ↑ "YaAZ-218". OldRussianCars.com. Retrieved 2013-11-20.
  21. ↑ "KrAZ-222". OldRussianCars.com. Retrieved 2013-11-20.

Sources

  • Shelton, Chris. "Then, Now, and Forever" in Hot Rod, March 2017, pp.16-29.
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