Welcome to the first in a series of stories relating to famous diesel engines of the past and present. I can’t think of a better one to start with than the Detroit Diesel Series 71. The story begins back in 1938 when GM subsidary Detroit Diesel unvieled thier first product, the two stroke, inline 6 cylinder 6-71. The inline models were offered in a one, two, three, four and six cylinder variants. In 1957 V-block versions were introduced and would eventually included 6,8,12,16,24 configurations. At first glance the naming convention seems cryptic but is rather straight forward when you think about it. For example, the 6-71. The six stands for the number of cylinders, the 71 stands for the cubic displacement of each cylinder. The 12V71 is a 12 cylinder in a V-block setup. To continue the code a T would stand for turbo charged. L or N would stand for low profile, a setup commonly used in buses. The larger of the 71 series in a V-Block configuration were usually two of the smaller setups married together our used the same set of heads allowing parts to be easily swapped. The applications of the 71 series were limitless. 6V-71 were common with bus and coach builders. 8V-71 were popular with firetruck manufactures, it is pretty difficult to find an old fire truck without an Detroit under the hood or cab. There is no question that the 2-cycle uniflow diesel engine design is more. Problem with the Detroit Engines are they are very noise and the 2 cycle leak oil like. Detroit Diesel 8V92 Sound Mod for Semi Truck. The sounds I make are with the new sound engine, so each vehicle can have a unique and different sound. Detroit Diesel 8V-92 Engine Sound mod for Peterbilt 351 Truck. But to really appreciated a Detroit you have to hear it, they truly have a sound all their own. So, on to the videos. 6-71 – 190 HP 12V71 – 450 HP 8V-71 – 318 HP I hope you enjoyed my novice homage to this great and long lived engine. Despite their unfailing ability to constantly leak oil you will still find fans of the 71 all across the globe. Please feel free to correct or and any relevant information by emailing [email protected] or just leave a comment below. If you have a candidate for the next KYD story let me know! Before GM made Detroit Diesels in V configuration, they married two or four 6-71’s together in”twin” or “quad” installations. I remember seeing two quad installations in the engine room of an ex US Navy inshore minesweeper. Imagine the glorious howl of two 24 cylinder powerplants at full throttle. Makes my spine shiver! I worked on boats with 6-71 and 4-71 engines. No matter how many cylinders, they all sounded the same to me, a nice throaty rumble at idling speed that became a uniquely soul stirring scream at 1800 rpm. I sniped a bunch of LCVPs, Mike6 boats, and Captain’s Gigs as an engineman in the U.S. Navy from 1973-1977. Motor Whale Boats too (Perkins powered). I became really proficient at trouble shooting and rebuilding Jimmies. It was my passion at the time. I used to rebuild and pop test the injectors as well. In addition, I also operated, maintained, and took part in rebuilding one of our Fairbanks-Morse emergency generators aboard USS Coronado LPD-11. Later in life I used to drive a 238 powered White 4000 single axle tractor with a 10 sp. Roadranger pulling tank trailers. Love the Detroit 2 cycle sound! By the waythe are made to run up to 2,100 rpm. Typical operation. Thanks for the memories! Further to my previous comment, I remember a pair of “handed” Gray Marine 6-71 engines, with Twin Disc marine gearboxes (Allison Division of GM) that had been taken from a landing craft, so they had been built during WW II. They still had their brass plates on the flywheel housing with the official number issued by the US Bureau of Ships. They had the larger injectors, and when the boat was fresh out of refit, they could push her along pretty smartly. We used to run up to 1500 rpm, but could push 1750 if needed. The biggest trouble was keeping the seawater cooling system clear of weed and mud which could cause overheating. The boat was eventually scrapped, but I don’t know if the jimmies survived. That’s so true Roy. As I remember (it was many years ago) you had a sea water strainer before the keel cooler you had to keep clear. The Jabsco pump did not like to run dry. We used to pack the rubber impeller with grease to lubricate them until they picked up salt water. It was just a half-dozen Phillip’s head screws to get the cover off. I would do it again! Sometimes the bosun’s mates would let me drive the boat (Mike 6 or LCVPs) I got pretty good at it!
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