Detroit Diesels

[Bob Huntress]

I read much discord about the Detroit Diesels 2 stroke engines, mostly the 71 series. I have worked with these engines in marine and heavy equipment applications for years. I have worked on older trucks with these engines. It is my experience that these engines are reliable and powerfull, though not fuel efficent. I am aware that many reasonable mechanics and operators see it differently, and I respect their opinions. I just want to share mine.

 

[Sam from WA]

i agree. the ol' detroits are a good, reliable engine with good power, but not the most fuel efficient. ya gotta love that 2 stroke scream.

 

[HeyPigFarmer]

I'll agree that they do have their ups and downs. Some people, like my father, love to hear a Detroit run... I would rather dig my ears out with a spoon. But that aside they do work awesome in marine and especially generator operations where they can run wide open, which is where they are the most efficient and have the most power. Same goes for them if they are on something like an excavator, the downside there is you do not want to be close to the exhaust for 8-14 hours a day, plus you don't want the sound of the engine drowning out what the labor is trying to yell at you. No design is perfect.

 

[Anonymous-0]

I have run a bunch of those old engines from 4-53 3-71 6-71 and 8V92. loved running them and love how they are to tune and adapt for almost any application. I still run a 34 year old semi tractor with the 8V92.
Just added a newer semi tractor with a Cummins 855, first thing I noticed is that instead of the electric motor smooth 2 stroke 600 rpm idle of 8 power strokes per turn of the crank, the 4 stroke 6 Cyl cummins with only 3 power strokes per revolution shakes the whole truck at 1000 rpm. I have had 6 Cyl Cummins in farm tractors for over 20 years, but this is the first in a truck.

 

[Sam from WA]

There is a bit of difference, i will have to agree. we've got an international s2500 with a cummins L10, it rattles and shakes a bit more than our old detroit powered kenworth

 

[MarkB_MI]

The longevity of the two-stroke Detroit speaks for itself. This engine was designed in the late 1930s and is still very much in use today. I figure they'll be around for another twenty years at least. Any engine design that's lasted seventy years with few major changes has proven itself many times over.

 

[Anonymous-0]

I'll disagree on the excavator application, at least for 6V53. I knew a guy who was one of the first to use hydraulic excavators for digging pipelines after using cable machines previously. He went through 5 P&H H418's and one 1250 which was the updated version. After that he went to Hitachi's and JD's. The 6-53's revved at 2650 RPM's and he wore a hearing aid. He said the 6-53's would need a major rebuild every 3000 hours. His first Hitachi with the Isuzu ran at around 1750 RPM's but lasted well over 9000 hours. I've heard the 71 series are better than the 53 series though. Dave

 

[ericlb]

i agree the 2 stroke detroit is nearly bullet proof, and it makes a great powerplant for equipment, for shear rackett nothing beats a 6-71 with straight pipes or riker exhaust [ how many remember those?] especially on a nice quiet night, my experience with one in a truck is that i think it was made to run at a more or less constant speed, and touque seemed to be way low when running up through the gears when compared to the big cam cummins i was used to driving, but i will say it never blew up, and i tried to do just that more than once your experience may vary

 

[Jerry/MT]

I had a JD 435 that had a 2-53 Gimmy and it was a hard starting devil in winter but was really easy on fuel.

 

[buickanddeere]

I cured my 435's cold weather starting problems.
Installed the proper N series pistons & injectors. The 21 to 1 compression ration vs. the factory S compression of 17 to 1 make higher temps on the compression stroke.
The N series injectors have a much finer and different shapped spray pattern.
A group 31 battery with 2/00 cables with the chassis return bolted right to starter body makes a difference too.
Getting the injector timing and rack setting correct will make or break cold starts too.

As for fuel efficiency? Many of the Detroits that were bit thirsty had over size injectors installed. Or were completely worn out but still managed to run all day, every day at full power.
I'd wager a late turbo intercooled Silver Series Detroit two stroke comes very close to the fuel efficiency of a 2008 emissions engine. And the Silver engine run pretty clean too.
For those people uncomfortable around electronics, the Silver Series is a pleasure.
Not bad for an engine Cadillac division released in 1938.

 

[CenTexFarmall]

I've always heard the the Detroits were generally a little better on fuel.
My grandad is a retired diesel mechanic and worked on those things for decades.

 

[bradk]

Something was wrong with your Detroits if they took more fuel than a comarable year and HP 4 cylcle.

We have four Olivers with Detroits(two 3-71's) & they take less fuel than even lower HP Waukesha engines.Our other two(4-53's) can work seemingly all day with a fill-up.My 1755 diesel would have headed back for a drink at noon.

 

[NC Wayne]

Been working on the old Detroits for about 10 years now and based on what I've seen I think their great engines. The only ones I've seen to be any tougher are the old Murphys that were used alot in the Northwest cranes. The biggest mistake I see people making with the Detroits is letting them idle too much or running them wide open them under no load. A Detroit loves a to be loaded. They need the load and the resulting heat to keep them from glazing the liner walls and burning oil or even worse not burning it off and wet stacking. Saw one in a crane catch the muffler on fire recently when it was finally run hard and got really hot after a long bought (a month or more) of lifting light loads and alot of idleing in between. Talking about reliability, the military uses alot of them. A recent rebuild on a 6V71 made it quite evident to me how many the military is using. I say this because many OEM parts are difficult to get, in a reasonable amount of time that is, because of military contracts taking all of them. That V71 I just rebuilt was being used as a power unit on a well drilling rig. The owner said it had been last overhauled sometime in the early to mid 70's using parts from several different engines. That story was supported by the facts I physically saw. When you know the guys uses good oil yet still find that the wrist pins are worn/grooved you know that takes alot of hard hours to get that far along. Then there was the fact that there were two different style rods used, and even the ones of the same style weren't "properly" numbered. Personally I think an engine that can run that long built using odd parts from several different engines is pretty tough.

 

[guido]

I also worked on those Detroit Diesels.
They got the job done like the other engines that we had. Cummins; Caterpillars; Macks; I.H.
As I recall fuel mileage was about the same in all of them.Tanker and dray operations was about 50/50. 3/71'S powered Olivers are very competetive in our antique pullers club, and sound good too!
Guido.

 

[El Toro]

The military used a lot of Detroit engines in their vehicles and we tested all of them. Here's
some of the vehicles. Hal
M109, M113, M577, M110, M564, M551 plus 2 Scout vehicles never fielded.

 

[greygoat]

The Detroit Diesel is alive and well in General
Motors locomotives, as a 16V645 two cycle rail-road Locomotive engine. This V16, 645 cubic inch
per cylinder is just a giant Detroit Diesel that
weighs 35 tons, in a 200 ton locomotive. Fuel use
at 200 Rpm idle is 20 gal. per hour. Full open at
800 Rpm, pulling a 1 mile long train 60 mph it
uses 200 gal. per hour. General motors also made
quite a few 20V645, V20 engines but had troubles
with the long crankshafts breaking, so current
production is a 16V710, 710 cubic inch per cyl.
that gives 4000 horsepower, and, due to newer
injectors gets about the same 200 gals. per hr
fuel consumption. Crankcase capacity is 400 gals.
of # 40 lube oil.
Most of the problems in the forum related to the
truck engines are common. After idleing for many
hours, a buildup of oil in the exhuast system can
produce an "oil bath" when the throttle is opened
up. These locomotives get an oil sample taken
every 2-3 days, filters are replaced every 90 days
but oil only when a sample indicates the need.
It is common to replace pistons and sleeves at
1 million miles. 1 trip a week between Chicago
and Seattle, and return, being common, 20000 miles
a month or more is not unusual.
I'm a retired Burlington Northern Santa Fe
locomotive mechanic.(certified heavy duty truck
engine mechanic)

 

[guido]

Hello buickanddeere
I agree with you about the silver 92DD. We had a bunch of them on tank work.They got the job done.
Running 100.000 miles a year in those days.
Fuel mileage was not an issue either!
The fuel squeezer model where a bit better on fuel, but the driver good negate that!
300.000 miles before overhaul, not many in chassis.Ours were cracking the block at the rear main bolt threads.
When the driver would tell me its running better then ever, that was my clue that they were about to blow up!

Guido.

 

[rustyj]

Our local fire company had a 671 Detroit, used as a pumper. One thing about that engine, it would run backwards, with a lot of noise and smoke.
One day, we had one of the guys out learning how to drive it. He pulled up to an intersection, and somehow, it stalled, and when he finally got the clutch out, the engine was running backwards. He stepped hard on the brakes and promptly deposited the whole bed lay of 2 1/2 inch hose onto the road! OOOPS!

 

[JDemaris]

I used to drive a milk-tanker that was Detroit powered. It was underpowered and I had to drive it with the pedal to the floor much of the time - so that's not a very good test. It was underpowered for our hills. I was trained early on that you were supposed to drive a Detroit like you were mad at it.

The Delco electric generators with Detroit 2-71s make 12KW of power at one gallon of diesel fuel per hour - and they are incredibly rugged.
Compared to something newer - a Kubota diesel genset makes 12KW a 1.6 gallons per hour, and an Isuzu does it with 1.1 gallons per hour.
It seems the two-cylinder Detroit beats them both.
In John Deere tractors - a Detroit 2-53 in a 440 is rated at 14.42 horsepower hours per gallon.
John Deere four-stroke 1010 diesel is rated at 12.6 horsepower hours per gallon.
Of course, the Deere two-cylinder 70 or 720 diesel beats them all.
I've got a genset, a large backhoe, and two dozers with Detroits and I love them - other than the oil trails they leave everywhere.

 

[guido]

Hello JDMARIS
Some of the oil that comes out of those Detroit
Diesels, also colled slobering by some, is sometimes coused by late injection timing.
If the leaking appears excessive I would check the injectors for proper hight adjusments. It would take just one of them to make the oil drip a lot more then the usual amount.
Guido.

 

[cornfarmer]

I use two trackmobiles with Driptroit engines, and they are bulletproof-one has run 18 years without an engine repair, this summer a short shaft that runs the supercharger broke. Only dislike is it is scary looking at the oil pressure gauge at idle.

 

[Howard H.]

Hi Greygoat!

That"s a very interesting set of comments you threw out!!

I"d love to see one of those big engines apart!

I saw a locomotive coming down the rails a few years ago with a 3 foot, huge orange flame shooting out the exhaust on a regular pulsing basis... Pretty spectacular! I wondered how they"d "limp it" to the repair shop or if they"d have to stop when they realized it was doing that...

A couple of weeks later, I saw the same locomotive come through again, still shooting the same type of pulsing flame - about 3 seconds on - 3 seconds off...

I guess they fixed it after that, since I never saw it again...

Howard

 

[bradk]

Heck,don't let the low oil press. scare ya.Never seen one with much pressure.

Just keep oil in it -n- you'll be fine.Run 'em hard and loaded.

 

[Anonymous-0]

They also love to run backwards when powering air compressors, as when they are shut off, the air pressure in the screw causes it to rotate backwards, acting like a starting motor. Not much fun.

 

[dieselpaul]

old detroits never die---thats why they stop with rack wide open-- ready to start at first taste of fuel. BUT fun begans whenya crank one thats set years, & one injector is stuck wide open--[locking all]--serious rpm result--[hope emerg kill works] later design gave us yield springs on rack---i never start one thats sit a long time without pulling cover--almost always find stuck in max fuel position--also, chk blower for stuck rotors--aluminum housings will ''chalk'' up inside--

 

[Ryne]

We've got two 4-71's one in a truck with an underbody blade and the other in a pulvimixer both pretty easy on the fuel but the one likes to wet stack if you dont get it working and get the rpms up, a bit loud and hard start in the cold without an aid, but overall good running engines i always say nothing roars like a working Detroit.

 

[JBruce]

Used a 2-71 in a hd 5 allis hyloader to log with for years. Built roads, packed the logs to the trucks, and pushed the tops. Would take 5 gal fuel along every morning for 4 days and nove the fifth day as it would not hold a full can. Built a bunch of terraces with the old allis and a 450c John Deere that was almost new at the time. Allis worked circles arou the JD on about one third the fuel.

 

[Anonymous-0]

I thought it was released by Oldsmobile division. Also where does Winton fit in this and also the 288(?) cubic inch marine engines. Thanks for any replys. J

 

[guido]

Hello buickanddeere.
Where did you get the pistons for the n injectors with the 21/1 compresiion ratio?
Guido