Detroit Diesel Series 71

Detroit Diesel Series 71 var en to-takt dieselmotor, som ble bygget både som rekke og v-motor. Som rekkemotor ble det bygget både 1, 2, 3, 4, og 6 sylinde varianter, som V-motor var den tilgjengelig som 6, 8, 12, 16, og 24 sylindre.

16V71 og 24V71 er utstyrt med 4 topper pr motor, for å holde dimensjoner og vekt på et nivå som det er mulig å håndtere. Har du løpet av en topp av en R6 eller V12 i et trangt maskinrom skjønner du hva jeg mener. Samtidig er det nok et kostnadsspørsmål. Ved å holde seg til færre deler i hele serien reduseres kostnaden.

6R 71 var den første toppmodellen som kom på markedet i 1938, fra det som den gang het Detroit Diesel Engine Division of General Motors.

Den føste V-motoren i serien kom i 1957.

Series 71 spiller på kubikstørrelsen på sylindene, hver sylinder er på 70,93 cubikktommer, eller 1,162 Liter. Alle motorene i serien har samme boring og slag, 197,95 * 127 mm.

Inline models were famously "symmetrical" , meaning that blower, exhaust, water manifold, starter, etc. could be mounted on either side of the basic block to fit a particular application. A number of models could also run either clock-wise or counter clock-wise, called "Right Hand" or "Left Hand" engines. The less common Left Hand engines were typically used in buses and boats.

All Series 71 engines use uniflow scavenging, where a gear-driven Roots type 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 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.

As a two-stroke diesel engine that does not use crankcase aspiration cannot naturally aspirate (draw in) intake air, a blower is necessary to provide sufficient air to scavenge exhaust gasses from the cylinders and to supply air for combustion. Later high-performance versions were available with turbochargers, and turbochargers with intercooling, the turbochargers discharging into the Roots blower intake. 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.

Serie 71 varianter

Model	Slagvolum	Byggeform	Ytelse
1-71	1,2 L	1 Sylinder	10
2-71	2,3 L	I 2	68
3-71	3,5 L	I 3	113
4-71	4,7 L	I 4	160
6-71	7,0 L	I 6	238
6V-71	7,0 L	V 6	238
8V-71	9,3 L	V 8	318
12V-71	14,0 L	V 12	450
16V-71	18,6 L	V 16	635
24V-71	27,9 L	V 24	1800

Modellkoder
T	Turbo
V	V motor
L	Lavprofil
N	4 ventilstopp