What did I just save from the scrap yard Detroit Diesel ? 20kw?

[digitaldust]

A Does anyone know what I have here ? It runs and makes 220 vac
help I need a TM to restore this from one end to the other




MIL-STD-251 seems to be the make model ? kato AC gen

 

[dependable]

You might also try Smokstack, it is an antique engine/tractor forum. Have seen postings with your unit on their generator sub forum.

 

[steelypip]

If that's a 2-71 Detroit Diesel, there were a bazillion of those (with civilian gen heads) used to run refrigeration sets on refrigerated box cars back in the day. 20KW is about the right size for one of those. Your gen head has that Army Signal Corps look about it. Those reefer gen sets are still circulating on the used market, and parts are plentiful. Smokstack is one good place to look for info, another is in the vehicle forums here because all two stroke Detroit Diesels need the same (slightly specialized) care, as they aren't quite the same as other diesels.

Try Googling 2-71 generator for a lot more info and some vendors.

 

[Munchies]

it wont be fuel efficient, but it will work!
Pre MEP - dod standardization when all branches had their own random equipment. Find the TM number and I can probably get it

 

[digitaldust]

does anyone know how to prime this it has a hand pump on the side It gets hard to pump the I start , it runs then stalls in under 10 sec.
is there a air lock ,

I do see a lever that has PRESS TO START on the top of the blower with the knob that is marked drupe.

I had it running yesterday but I ran out of fuel and not its a no go for run .

 

[steelypip]

it wont be fuel efficient, but it will work!
Pre MEP - dod standardization when all branches had their own random equipment. Find the TM number and I can probably get it

Not sure about fuel efficiency - after all, in the 20 KW size range you're competing with things like MEP-004As. This website says:

The 2-71 Detroit Diesel Generator will use approximately ½ gallon of fuel per hour with no

load. The unit will use approximately 1 ½ gallons per hour under full load.

That's not that bad - the no load fuel consumption is about the same as an MEP-003A,which only makes about 12 KW in overload. Fuel consumption on an MEP-004, which is rated for less output, and won't do single phase without mods, is higher.

Now, if you don't think you need 20KW of generating capacity then you're feeding a lot too much generator. But if you do need, say, 15 KW continuous, I'd look hard at this over an MEP-004A because of the simplicity and the nicer gen head.

 

[Munchies]

I have never tested a 004a for consumption, and I was simply guessing based on my other 2 stroke detroit experience which not being much knows they burn oil and like to rev.
The 005A I did test for consumption was around 1.5 gallon/hr at 35kw and somewhere around 1-1.25 if memory serves for half or maybe it was 20kw load. Are those 4cyl's that inefficient?

 

[rustystud]

does anyone know how to prime this it has a hand pump on the side It gets hard to pump the I start , it runs then stalls in under 10 sec.
is there a air lock ,

I do see a lever that has PRESS TO START on the top of the blower with the knob that is marked drupe.

I had it running yesterday but I ran out of fuel and not its a no go for run .

OK, now you screwd the pooch ! You never run these units out of diesel ! These older diesel units do not have the priming system the newer MEP's do. You will have to pressurize the fuel system. What we do at my job is get a old propane tank, remove the valve at the top. Then you will have to solder in a tube to the bottom of the fitting ( .25" copper will work) you might have to drill out a hole for it . This tube should go almost to the bottom of the tank. Fill the tank half full with diesel. Then reinstall the fitting. Now you will have to make up a fuel line that will go from the old propane tank to your fuel system. You will need an adapter from any propane using device (old BBQ ). Then make up a fuel hose from the adapter to a fitting on your generator. You will have to take off a line before the filter. Then you will pressurize the propane tank with air, using the adapter to the tank. Then after the tank has air pressure (about 40psi) close the valve and install the fuel line to the generator. Break loose the injector lines at the injectors. Then open the tank valve, this will start sending fuel into your system. Once fuel starts coming out of the injectors, tighten the lines, and close the tank valve . Remove the fuel line and reattach the original fuel line to the generator. It should start up at this time.
Of course you could just crank the crap out of it with the injector lines loose and hope it primes before you ruin the starter or the battery !

 

[steelypip]

I have experience with different vintage diesels, but yeah - you should do whatever is necessary to avoid running one out of fuel. In many cases, you have to take the injection pump partially apart to get the thing cleared of bubbles enough that it will pump fuel at all.

 

[Triple Jim]

Just for reference, the 2-71 diesel powered box car generators that I've seen run at 1200 RPM.

 

[steelypip]

Apparently 2-71 gen sets were used for electric power on a lot of smaller marine vessels, and used by AT&T for backup power as well. For whatever reason, 60 Hz 12.5 and 20 KW sets are not rare. A little research is showing that the 1200 RPM sets were 12.5 KW and the 20 KW sets are the more usual 1800 RPM, which makes sense given that the engine has the same displacement in both cases. There were also, apparently 2-53 and 3-71 gen sets as well.

 

[CDR]

Sweet find I love detroits

 

[rustystud]

I have never worked on a 2-71 Detroit, but I wonder how it is on vibration. Is it like our MEP-002A ? Mix your paint can will generating power. Of course I would love to have one !

 

[steelypip]

Recip engine vibration is a complex topic. There have been quite a few long books written about it. With an inline two cylinder, your choices are to have both pistons bobbing up and down on the same stroke, or to have them on opposite strokes. If you put both on the same stroke, you are basically balancing a bigger one-cylinder engine. There's a vertical component (pistons bobbing) and a horizontal component (crank throws swinging) of different magnitude, and if you fully balance one, the other will be somewhat out of balance. The only way around this is to use a balance shaft (ideally two balance shafts, one on either side of the crank centerline) to counteract the difference between the two, which costs power and complexity, so you're not going to see it in an industrial application.

Put the pistons on opposite strokes and you can completely balance everything...except for the rocking couple between the two cylinders. So now instead of wanting to jump up-down or side-side, your engine wants to shimmy around. The opposite-strokes arrangement is often used on motorcycles because it gives an odd firing order, which is preferred by some motorcyclists. You know which you've got by whether the whole bike bobs up and down at idle (pistons on same stroke), or you get the 'magic fingers footpeg' phenomenon at high RPM from the rocking couple wiggling the frame (pistons on opposite stroke).

Given that the Detroit is a two-stroke, that means that each of its power pulses is half as strong relative to a four stroke. That should smooth power delivery out some, but won't do a thing for balance.

 

[digitaldust]

ok its a 1957 2-71
also I have it running I need a spec and info to work on it , it looks like the head gasket is blown out the side of the head its a black thick paper.
and then I need a paint pattern.
any one have a PDF on the engine

 

[patracy]

HOLY COW!!!

My grandfather had one of those, but never did anything with it. Unfortunately I was a teenager when he passed and didn't think anything about it when we went through his things. That's the one thing I wish I would have gotten. (And his pickup truck) I recall as a small child going out to his barn and "driving" in his truck. Then playing with the generator. (Just playing with the primer and stuff like that)

If you ever want to part with it, let me know. I'd only imagine the one of my childhood has already been melted down and is tin cans now in some landfill.

 

[Triple Jim]

Given that the Detroit is a two-stroke, that means that each of its power pulses is half as strong relative to a four stroke. That should smooth power delivery out some, but won't do a thing for balance.

Interesting. I normally compare 2-strokes to 4-strokes on a per displacement basis, but when compared on a per power output basis, you're right, each power stroke produces half the power.