4-71 detroit info/help

[TSK415]

I have a dragline with a 4-71 DD it's new to me. But no past history, it's wet stacking bad. I went over some past posts and did some back ground checking and now I an looking for some direction. Ser# 4A 39878 4-71 RD 9 (serial # doesn't match what I have) injectors are HV7 Things I have done so for, changed oil to a straight 30 wt. plus oil and fuel filter. Valve lash is right on, injector timing right on. But the GM maintenance manual I have does't cover the governor that is on the engine to get me to checking the fuel injector rack. Crank case vent on the lower right bottom of the block is open are there more? Breather off the govenor is open. Some oil on the blower rotors. No broken or stuck rings, pistons and cylinders look good. I don't think it's blowing oil as much as it's blowing fuel. I can't get it hot, after an hour running and revving with the radiator covered up the best I can do is about 130* and the thermostat won't cycle.

 

[TSK415]

A few more

 

[willie59]

Wet stacking? Maybe it's just the pic, but I don't see much oil leaking from the vent tube fitting. What makes you think it's blowing fuel? And how can you not get temp above 130 degrees? Are you sure your gauge is reading correctly? Looks like a fairly clean Detroit.

 

[soso]

pull off the valve cover ad see if you can see control rods for the injtors see if all the racks are moving the same i will dig out my shop man tommow for you.

 

[Komatsu 150]

I think the spec was straight 40 weight oil. They were cold blooded even with a good thermostat with no load it was hard to see 150.

 

[biggrader]

one of the cleaner 471's, have you checked the thermostat for opening temperature. If it in fact is running that cold you will get some degree of wet stacking. Any ideas on how many hours are on it? I'll get some more info for you tomorrow on checking the rack.

 

[Cowboy Billy]

The engine iol has to low ash CF-2 compliant. Such as Rotela T strait weight or Delo 100. Delo 400 no longer has the correct certification.

I believe the 4-71 is like my 6-71. In that there is a emergency shut down flap on the blower. It has to be reset at the blower! I tripped mine last fall and while it ran fine at a idle it had no power and blue out tons of black smoke.

 

[TSK415]

Thanks for the replies

Wet stacking? Maybe it's just the pic, but I don't see much oil leaking from the vent tube fitting. What makes you think it's blowing fuel? And how can you not get temp above 130 degrees? Are you sure your gauge is reading correctly? Looks like a fairly clean Detroit.

Your right, hardly any oil out the vent, a little more out of the breather vent. Blowing fuel was a guess because the wet stacking seems thin, like diluted oil. As far as the temp, the guage is old, I was shooting the engine with a temp gun, and the thermostat never cycled and no coolant getting pushed into the top of the radiator. the right side of the motor is very clean it's the other side is the mess

pull off the valve cover ad see if you can see control rods for the injtors see if all the racks are moving the same i will dig out my shop man tommow for you.

The control rod and injector racks seem ok. but the info from the manual would be great

I think the spec was straight 40 weight oil.

The GM book showed 30wt but everyone is recommending 40wt and I'll be going to that.

one of the cleaner 471's, have you checked the thermostat for opening temperature. If it in fact is running that cold you will get some degree of wet stacking. Any ideas on how many hours are on it? I'll get some more info for you tomorrow on checking the rack.

Hope to check the the thermostat this weekend. About the hours, no idea. When I was looking in the inspection covers at the cylinders, it looked like it had been freshly honed.

I believe the 4-71 is like my 6-71. In that there is a emergency shut down flap on the blower. It has to be reset at the blower! I tripped mine last fall and while it ran fine at a idle it had no power and blue out tons of black smoke.

Emergency shut down is good and works, all I get is white-light grey smoke.

I guess I am looking for more info on setting the govenor, thanks again for the help

 

[willie59]

Hmm, still not certain what your describing your wet stacking condition. Just to be sure we're on the same page, you can see three hex fittings just behind the oil filter can. The one nearest rear of block is a 90 degree flare fitting, that's what's called the "air box drain". There should be a short piece of tubing connected to that fitting to extend the drain to just below oil pan to keep drippings from getting on the block and oil pan. There will be a crankcase vent pipe as well, usually located at rear of engine, and will be about a 1" diameter pipe. Are you getting leakage from the air box drain or the crankcase vent?

As for governor adjustments, are you having a governor problem? Unless someone has played monkey wrench with it, it shouldn't need any adjustments.

Engine temp; when you were aiming a temp gun at it, were you checking the temp of the block? The engine block on a Detroit doesn't get terribly hot because there is air from the blower moving all through it feeding the cylinders. This also keeps the block cool. The only part that has coolant in it is the engine head. And Detroits used a low volume water pump. You should see some movement of coolant in the radiator neck when thermostat opens, but your not necessarily going to see a rush of coolant, maybe just movement of coolant.

SAE 30 was the old Detroit oil spec. Detroit has since done some research and found SAE 40 gives better results. SAE 30 would be used in very cold climates. And as Cowboy Billy noted, it must be a CF-2 oil, and it should have a sulfated ash content of 1.0% or less. Delo 100 meets the spec the best, Delo 400 won't do, Texaco Ursa is good, Rotella is borderline as it's ash content is around 1.0%. It will work, just not the best for ash content.

I'm wondering if you may have some failing injectors. You could simply remove the injectors and have them tested. Also, since you don't know the history of the engine, it's possible someone has been using multigrade 15W/40 in it, they will slobber when you use that oil. I would advise, now that you've changed it to SAE straight weight oil, is run it and run the dog snot out of it. Put a few hours on it, then change the oil to SAE 40. Keep us updated on how it works out, and be sure and post some pics of your dragline.

 

[mitch504]

Dog snot?

I have several -71s and a couple of -53s. Atco said everything I was going to, and I agree with him completely. But, I do run 15w-40 Rotella T in mine to prevent confusion w/ rest of fleet. The DD's do slobber if you let them idle to long or run fast w/ no load. You will never get temp. up without load. If mine slobber you can run them hard for a while (it does seem the longer they slobber the longer you have to work them) and they will clear up. Also, don't lug them, the work they are happiest with is running 3/4 throttle or better with a steady load.

I would keep the dog away when he is sick. Once they are full of dog snot it takes working them hard and steady to clear them.:tong

 

[Dirtdozer]

In my case all my Detroit's slobber. I think you may have an oil er ring bad. You have the inspection covers off and would have seen that. Can you pull the exhaust manifold to see which cylinder it is coming from. It could be a stuck injector too. I know the n65's are pretty notorious for that.

 

[Komatsu 150]

Atco said: "SAE 30 was the old Detroit oil spec. Detroit has since done some research and found SAE 40 gives better results. SAE 30 would be used in very cold climates."

I remember having the service bulletin from GM updating the oil spec to 40 weight. Of course doesn't mean I could ever find it.

 

[Willis Bushogin]

4-71

Thanks for the replies

Your right, hardly any oil out the vent, a little more out of the breather vent. Blowing fuel was a guess because the wet stacking seems thin, like diluted oil. As far as the temp, the guage is old, I was shooting the engine with a temp gun, and the thermostat never cycled and no coolant getting pushed into the top of the radiator. the right side of the motor is very clean it's the other side is the mess

The control rod and injector racks seem ok. but the info from the manual would be great

The GM book showed 30wt but everyone is recommending 40wt and I'll be going to that.




Hope to check the the thermostat this weekend. About the hours, no idea. When I was looking in the inspection covers at the cylinders, it looked like it had been freshly honed.



Emergency shut down is good and works, all I get is white-light grey smoke.

I guess I am looking for more info on setting the govenor, thanks again for the help

Good info from everyone and I can only repeat some things
These DD will run forever, I always have used 40W oil in these engines
They dont like to idle long, they love to run wide open under a load
I was thinking the thermostat was 165 degrees and as stated, it will run cold under no load. Did your thermo gun match up with what you were readying at the sending unit (good way to check the guage)
I would work the crap out of it, for a few days and see what happens
I dont think the governor has an issue, unless someone messed with it and even then it wouldnt cause wet stacking

As stated I would pull the injectors and have them tested
You really need to have someone re-install them that knows what they are doing and has the correct timing tool.

Is this a 2 valve or 4 valve head, if its a 2 valve, it never will run real clean

Looks like a pretty clean engine to me also

Can you feel air coming out of the air box drain, you might have to run it hard to check this. An old trick if this air box drain is stopped up, is to pump about 20-30 pumps of a regular greas gun and grease in this hole. You can screw the end of a grease gun hose in the block, or screw a grease fitting in it. Pump the grease (good if the block is warm/hot) take out any fitting that maybe in the block and start the engine and run it real hard, the grease melts and cleans the crap out and just blows out.
Good Luck and keep us posted

 

[Willis Bushogin]

471

Wet stacking? Maybe it's just the pic, but I don't see much oil leaking from the vent tube fitting. What makes you think it's blowing fuel? And how can you not get temp above 130 degrees? Are you sure your gauge is reading correctly? Looks like a fairly clean Detroit.

ATCO, help me a bit here, does this look like the correct governor cover on top? This is a shutoff lever and I was thinking the top just had a one shaft coming out of it, also what is this spring doing, thats hooked to it? It cant go in the forward direction, because it will hit the extra shaft and so if you pull the stop lever back to stop it, the spring doesnt do anything.
Maybe the lever goes forward over the front shaft, but I always thought I had to pull back on it

Do I see oil residue below the bellhousing? Wonder if the rear seal is leaking?

These questions, has nothing to do with possible wet stacking, just wondered about these things

 

[willie59]

ATCO, help me a bit here, does this look like the correct governor cover on top? This is a shutoff lever and I was thinking the top just had a one shaft coming out of it, also what is this spring doing, thats hooked to it? It cant go in the forward direction, because it will hit the extra shaft and so if you pull the stop lever back to stop it, the spring doesnt do anything.
Maybe the lever goes forward over the front shaft, but I always thought I had to pull back on it

Do I see oil residue below the bellhousing? Wonder if the rear seal is leaking?

These questions, has nothing to do with possible wet stacking, just wondered about these things

Hi Willis, that's a variable speed governor on that engine. I once operated an HT300 Link Belt with a 6-71 that had a governor just like that. It was ideal for operating a crane because it maintains engine rpm regardless of load changes. You could pull the throttle lever back to say 1500 rpm, and work the cranes functions, and the rpm would hold at 1500 because the variable speed governor throttled the engine. It was even kinda neat for driving the machine on the highway. Once you got in top gear and up to speed, just pull the throttle control on the dash panel. It acted like cruise control, holding rpm at a certain spot. Get on a little grade, and it would throttle the engine. Get to top of grade and flatten out, it would back off the throttle. That is the shutdown lever on top of the governor housing plate, it rotates CW to shut down engine. The spring is holding it in the engine run position.

 

[Speedpup]

My DD manual for 3-71 said 40 wt I have been running 15-40 because I didn't know any better till it was discussed here.

 

[willie59]

Here ya go fellas, plenty of good Detroit reading. Tejas Coach has been working with Detroit fleets for many moons and they've put some really good info on the interwebs.

http://www.tejascoach.com/ddcoil.html

 

[Speedpup]

Here ya go fellas, plenty of good Detroit reading. Tejas Coach has been working with Detroit fleets for many moons and they've put some really good info on the interwebs.

http://www.tejascoach.com/ddcoil.html

Thanks good read!:drinkup Guess I'll get some 40 wt at the DDD. Detroit Diesel Dealer may be the 40 wt will kill some of the smoke

 

[surfer-joe]

I would ad that the inside of the blower looks normal and the outside of the engine also looks normal. A very typical 471. In my experience, every 71 series diesel ran best at full rpm under load. They did not like to idle at all. This includes the two cylinder models to the 16V's.

Heavier oil will help some, having the HV7 injectors checked out and maybe exchanged or rebuilt would probably help a bit. It would also help if the coolant temp was raised to at least 165, maybe 180. That will tighten things up inside some and help control the oil leakage.

Good Luck!

 

[Speedpup]

The more I read on that site and the links (
http://www.tejascoach.com/ddcoil.html) the sicker I got about running 15/40 all the years in mine. It is a yard machine and not tons of hours but still make me :Banghead:Banghead