Range required to cross the nulla

[Busman]

I would differentiate between a blower (good descrip T1) and a supercharger in that a supercharger in my lingo is an additional part of the setup, can be removed, is usually belt driven and sits atop the carby if there is one, or atop the inlet manifold if not. Faster engine goes, more air is jammed into each cylinder, as opposed to say a GM blower that is designed as an integral part of the engine, again a good descrip above.

Have spoken to quite a few water mist sellers and all do say you can inject before the turbo BUT ONLY if you have the nozzle and pressure to produce very fine droplets, otherwise the problems T1 alludes to above can happen.

[Toolman]

My 6V92TA also has a bypass blower which I understand allows more boost

[BruceS]

Bypass blower or a wastegate?
Unfortunately the more complicated they make them, the more things that can go wrong.

[Toolman]

Bypass Blower. 350Hp 6V92

[T1 Terry]

My 6V92TA also has a bypass blower which I understand allows more boost

I thought that might have been getting a bit too far into the tech discussion There is gate or valve if you like with reasonably light spring loading to hold it closed in a path around the blower housing. When the blower is creating all the air flow (idle and low crawling mode) the spring holds the gate shut, as the engine revs build the exhaust pressure increases the turbo speed and the blower is force fed. As the pressure into the blower increases the blower reaches a stage it can not carry all the air supplied by the turbo due to the engine speed and blower speed being a fixed ratio, the pressure builds till it overcomes the gate spring and forces air around the blower. This further increases the cyl charging pressure and some claim it reduces the load on the blower, I can't see how that could be as the blower now has to dump into a higher pressure chamber so I believe the blower load would be increased.... but that is getting a bit beyond the scope here eh
If the 2 stroke diesel concept had remained I believe the introduction of Li batteries would have lead to electrically assisted turbos completely replacing the mechanical blower, computer controlled valve timing could have controlled combustion temp and computer controlled injection could have radically improved the fuel economy and torque, but that is just theory now, the 4 stroke diesel engine won out

T1 Terry

[Wilbor]

Well I'll be blowed! I've learnt more about that boat engine in the last day than I did driving it for a year or two!!! Easy to see I was just the skipper not the engineer!!! It's good to be able to hand it over to someone else to fix it and keep it going . Mind you, in the time I ran this boat I don't remember it ever having an mechanical issues with the GM. It just kept on going and probably still is

[T1 Terry]

A brilliant boat engine, emissions aren't an issue and torque all the way down under load isn't really an issue but set to its optimum revs it would go all day every day. I was once told it was originally designed and built as a marine engine and later adapted to road use, no idea if there was any truth in that though or if it was just one of those urban legends.

T1 Terry

[Toolman]

Here is a copy and paste of a brief DD history

In the late 1930s the brilliant design team at the GM Research Laboratories, led by Charles Kettering, set out to develop a versatile high speed diesel engine that would be suitable for a wide range of automotive, marine, and industrial applications. The result was the GM Detroit Diesel 71 series, one of the most successful and long lived diesel engine designs ever produced. The 71 series engines are named for their swept displacement per cylinder (in cubic inches), a naming practice that Detroit Diesel shared with the Electro-Motive Division of General Motors.

The main incentive for the development of the 71 series was GM's truck production and their partial ownership of Yellow Coach. This provided an immediate market for thousands of the engines, but the designers also made advance provision in the design to accomodate marine exhaust manifolds, a wide range of engine mountings, and marine transmissions. Consequently the engines could also be used for a wide variety of marine or stationary power generating, power takeoff, and pumping applications.

The 71 series, introduced in 1938, are two-stroke cycle uniflow scavenged engines, with the air entering the cylinders through a ring of ports in the cylinder liners, and the exhaust exiting through valves in the cylinder head. In early production all the engines were fitted with engine-driven Roots blowers, but late production some models of the 71 series were available in versions having a turbocharger in series with the Roots blower for higher power output.

Eventually the series would be built in one, two, three, four, and six cylinder inline models. The four larger engines were well equipped for use as ships service engines on tugboats, and the 4-71 and 6-71 were often used for propulsion in smaller tugs and workboats, singly or in twin or quad sets. When the US entered World War Two, the 71 series were adapted to many military applications, including propulsion packages for tanks and use in landing craft, ships' boats, and shore based power generating plants. Following the war the two cylinder model was widely applied as a refrigeration engine in railroad cars.

The 71 series served as the design model for a number of other engines, both larger and smaller. In 1945 GM introduced the larger but very similar 110 series uniflow scavenged engine, which proved successful in many marine and railcar application. There were both Roots and centrifugal blower versions of the 110 engines. Around the same time they introduced the smaller 51 series valveless cross flow scavenged engines. The 51 series was built in small numbers, primarily as a marine and industrial engine, and today they are very rare and eagerly sought by engine collectors. The 51 series was replaced in the product line by the more conventional 53 series uniflow scavenged engines in the 1950s, and was used in a wide range of marine, railroad and industrial applications as well as in trucks. Vee versions of the 71 series were also developed in this time period, and became a widely used bus engine for several decades. In 1967, Detroit Diesel introduced their larger 149 series engines, which share design similarity with features of both the 71 series and the GM Electro-Motive division 567 and 645 engines. The Detroit Diesel 2-cycle product line was further supplemented by the very similar but more powerful 92 series engines, introduced in 1973, basically a larger bore version of the 71s, which are still produced for certain military and specialty uses.

The Detroit Diesel 2-cycle product line was acquired by MTU in 2006, and they continue to provide parts and support for these engines. The Detroit Diesel 110 series was last produced in 1965. Production rights for the 110 engines were acquired by W.W.Williams Company, which manufactures parts for this series.

Article and page design by Preston Cook, ©2009 by T.E.S.

[bob r]

Gee I always thought V871 detroit engines were built for boats, but for anchors not to drive them.

Bob

[T1 Terry]

Gee I always thought V871 detroit engines were built for boats, but for anchors not to drive them.

Bob

You either loved 'em or hated them, there was no other choices, no other engine can turn fuel into noise quite like an 8V71 320hp from such a compact engine that would just go and go if you regularly changed the oil they were the backbone of many trucking companies. Drive it like you stole it was the about the best advice to get the real performance out of these beasts and that meant they were nearly cowboy driver proof. The Cat 3208 was another great workhorse although not near as powerful at only 210hp, but you couldn't drive them like you stole it unless you wanted to regularly replace camshafts and head gaskets, but treated well they kept on going and going