Help me aquire some history on the GMC blowers

All I know is that they came on... GMC trucks back in the day. That is all ive found though. The allure of "back yard" speed equipment that actually would have been used back in the 50s is something that mesmerizes me. Being a youngster I have no knowledge of these factory add ons.

My questions: What exactly did they come in? When did gm stop using them? And if anyone has pictures of one in it's natural habitat it would be greatly appreciated.

Thanks for any info, -Webb

 

Google image search for: GMC 671 diesel engine

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4, 6 and 8 cylinder engines..... Industrial GM as well as some vehicles. 71 cu in per cylinder, thus the 4-71, 6-71 and 8-71 designations. If you google say, 6-71 GM diesel engine you should get a pretty good history. LOTS of road building equipment used them.

 

They were used on diesel powered Sherman tanks during WWII.

SAFU

 

Also used on GM Buses

 

<TABLE cellSpacing=0 cellPadding=0 width="98%" border=0><TBODY><TR vAlign=top><TD>Roots
This manufacturer provided blowers for industrial air supply and purging diesel engines. They were frequently original equipment on large diesel bus engines; &#8220;GMC&#8221; is General Motors Coach Division. The numbers by which they are frequently

</TD><TD></TD><TD align=right><TABLE cellSpacing=0 cellPadding=0 border=0><TBODY><TR><TD height=25></TD></TR></TBODY></TABLE><TABLE cellPadding=0 border=2><TBODY><TR><TD></TD></TR></TBODY></TABLE></TD></TR><TR vAlign=top><TD colSpan=3>identified contain a code as to the size (pumping capacity) of the supercharger. There are 3 common rotor diameters, and up to 7 case and rotor lengths in some types. The case length is the pre-fix (3-, 4-, etc.). The suffix -53, -71, -92 indicates inches per cylinder on the original installation engine, and determine rotor center to center distance and case width. Although frequently used to supercharge V8 engines, none of these were originally made for this purpose. The most frequently used size for street engines are 4-71, 6-71 & 8-71.

</TD></TR></TBODY></TABLE>

 

As I remember, they were for exhaust, not induction, in their original application.

 

Thanks guys, The number designations were something I didnt know.

I know its nearly impossible now but I always pictured one of these on a V8 powered old big rig but I never knew what used them if any at all.

 

Can't tell you much about the car side of using the 6-71s, but, having been around older trucks a fair bit here's what I can tell you as far as where they came from:

Mostly on the 6-71 diesel engines (which were also built by Detroit Diesel which was owned by GM at the time), I believe several of the other models could be had with the superchargers, as well. ***mins also produced several super-charged diesel engines around the same time (the 275 and 300 "Iron-Lungs", also known as "two-six-bits"), although I haven't heard of anyone using the superchargers on an Iron-Lung for speed equipment. The engines (the diesel engines, that is) sound mean, would be worth your time to go to youtube or some video website and look up "6-71", "Screamin' Jimmy", "275-Iron Lung", "300 Iron Lung" etc. Always mounted on the side of the engine when in a truck, at least if its an inline. The supercharged diesels had a reputation for being touchy motors sometimes, and, depending on who you talk to (as with all things in trucking) some drivers will tell you they're one of the best old diesels built, and other's will tell you they can't get out of their own way. You can always tell a supercharged diesel from the sound, get kind of a "bark" when they're up high in the RPMs the way I see it.

 

Koy: you were right videos were well worth the time. Those sound so mean.

So most superchargers were used on diesels and such were V8s an uncommon home for such a piece?

 

The roots supercharger became so ***ociated with hot-rodding and racing that if you showed a photo of an old v8 with a supercharger and a six-banger diesel the person would probably be more surprised to see a supercharger on a diesel engine than a gas-job (unless you were showing this to a VERY old truck driver).

 

71 series Detroit diesels were built from 1939 to 1987 for truck use, into the 90s for industrial use. 92 series was a modification of the 71 series, built from 1977 to 1987. They also built a 52 series, and 104 and 144 series. they came in 2, 3, 4, and 6 cylinder inlines, and 6, 8, 12, and 16 cylinder V models. All used a supercharger , and were 2 cycle with intake ports, and exhaust valves.

 

The range of different GM Detroit Diesels is as follows: 53,71,92 110 and 149. These are the common two stroke diesels used in trucks,buses and other industrial applications including earthmoving equipment and locomotives. There was a lesser known series ,the 51. This had no valves at all and exhaust was scavenged by ports. Apparently not used for automotive purposes.

As stated this numbering refers to the cubic capacity of each cylinder of any given engine. Often a V is utilised in the description of the engine. This simply means the engine is in a "V" formation. Be careful of this as for example a 6-71 blower and a 6-V71 are different engines and have different blowers on them.

These blowers performed the scavenging function necessary on a two stroke design engine. They didn't actually "supercharge" as such which, by the way, is a function of valve timing.

 

gennie marie clark

 

freduce has it but you guys forgot to note the marine engine 24v71 two v12s bolted up and the 16v92 and the 16v149 . general motors also made a 1-71 all with blowers

 

The original is by the Roots brothers and was used as an air pump for miners.

 

A good reference book for you is "Street Supercharging" by Pat Ganahl, which can often even be found at Barnes & Noble, Borders, etc. A good read, and it covers more than just the GMC blowers. About $20 or so last I looked.

 

just go to a heavy truck or machinery salvage yard. they came on any DETROIT DIESEL that was a 2 stroke. we have plenty of them in our fleet of machinery.
nothing like the noise of an old DETROIT.

 

they were a 53 series. the only other difference between 71 and 92 series. other than displacement was 92 series was changed to wet sleeves. Most later engines even had a turbo set right on top of the blower. Ever seen one runaway till it makes a bomb. run like hell.

 

I know. I was in a hurry and did not proof read. 53, 71, 92, 110, and 149. Try having one run away while you are laying on top of it under a cab over truck cab. Whole new meaning to excitement. between 1978 and 1980 I overhauled one 92 series V6 a day . Over 450 in all.

 

I put a 4-71 in a Michigan loader, a 6-71 in a Case 1470 tractor, a 6V-71 in a Allis Chalmers AC 440 and a 8v-71 in a Farmhand tubgrinder. I liked them a lot, very difficult to hurt, not big on torque, but a great engine to run against the governor all day long. I really wanted to put a 12v-71 in something, but never got the chance.
Some say they were a big part of winning the war in the Pacific.

Old B

 

A mate of mine runs a 12V71 in his R190 Inter. Races it on the salt here in Oz. Has been up to 133mph. He is now playing with a twin turbo set up and looking to up the speed a bit more.

 

HOLY BLOWER BATMAN!

Industrial use

 

I guess you can legitimately call those things "big ****ers" .

 

"... seen one run away..." That brought back a memory & a laugh. When I was in the Navy I cut my diesel teeth on 12V-71 TTI Detroits. (twin turbo, intercooled). They had two 6V-71 blowers on top, coupled thru a steel shim spring pack. I still have the scar from those *******s. We had one run away on us, tripped the flaps, literally ripped the fuel supply line off before it finally slowed down and died. Damn near **** meself I did! We saw about 2450 rpm on the tach at the highest point.
If you can find one at a s**** yard, it can be converted over to street use by changing the end plates and running looser clearances. 71 series Detroits ran around 2100 rpm max, and you'll need bearings and end plates that can turn your motors rpm. Not sure who makes conversion stuff nowadays. Dyer did back in the '80s but I'm not sure if they're still around. They're pretty easy to work on. Just get the Detroit Diesel matched gear puller set & the long feeler gauges.

 

Would someone decode the following:

1V-471

2v-471

3V-471


2) How did GMC handle the filter issue?


3) P.S., i think GMC stands for General Motors truck Company, Not General Motors Corporation.

 

Don't know what those numbers might be but the series designations usually had to do with number of cylinders and configuration.

2,3,4,6-71= inline 2,3,4,6 cylinder 71 cu. inches each. V6-71 would be a V6

The air filter was connected to the inlet with a cast aluminum manifold and on some like the V series also had a turbocharger plumbed in there.

I think GMC originally made trucks but GMC stands for General Motors Corporation.

 

Here is a pic of my mates Inter with the 12v71 now sporting twin turbos.

 

a few 71 series have been forgotten. a ONE seventy one and a TWO 71 series. Real scarce,mostly built in '30's thru early '50's in industrial applications. 1-71's were used on the generators for the searchlights protecting London. These scraming *****es are beyond neat. They are 2 cycle so fire every stroke. they can be run WITHOUT rodcaps because every stroke is pushing down. NEAT

 

I dont think so. What happens when you shut off the fuel rack? No power then? Rod and crank will part company and game over.