8V92 Detroit Diesel

[ms0115]

Wondering if there were any Detroit diesel mechanics out there that would let me ask some questions about problems that I am having with a 8V92 Industrial .

Thanks

 

[mitch504]

I've spent a lot more time with 53s and 71s than 92s, but ask away. I'm sure I or someone else can help.

 

[ms0115]

I have a 8V92 on a well drill rig (deck motor). Came in down on power, had 3 bad injectors and a stopped up inner cooler. No tags or numbers stamped anywhere on the block. Suppose to be a 500 hp unit. It has 9290 injectors and all the info I find says the injector sets at 1.484; But they run out of stroke at this setting. They were set at 1.60 when it arrived. It will crank and run at this setting, but the performance is not right. Any ideas on the correct setting? I have done a lot of in line DD work, running everything the same way. Thanks for the help.

 

[kshansen]

Not sure what you mean when you say "they run out of stroke"?

Also what was stopped up on the inter core? Assume this was either replaced or cleaned out.

I did post your question over at https://groups.yahoo.com/neo/groups/DetroitDiesel/info

to see if anyone there might have some thoughts.

 

[RZucker]

Was the original setting 1.460? I don't know much about the industrial 92s, but most industrial V-71s run a 1.460 setting with standard cam timing and 1.484 makes them run like a dog.

 

[kshansen]

Was the original setting 1.460? I don't know much about the industrial 92s, but most industrial V-71s run a 1.460 setting with standard cam timing and 1.484 makes them run like a dog.

That makes sense as the higher the injector is set the more retarded the injection is going to be on the engine.

Still don't understand what is meant by "out of stroke". Might just be a terminology difference.

 

[Former Wrench]

The 1.484 is for advanced timed engines; usually turbos. It goes with having the idler gear advanced one tooth. The higher the injector is set, the sooner the rocker arm will depress it.

I am pretty sure there is a model and serial number on the block. Look for a flat machined spot; maybe above the oil cooler or on the top of the block behind the blower near the front of the flywheel housing.

A couple of things to check. Put a small screw driver in the rocker and injector arms and wiggle to check the bushing wear. If there is any play, they are shot. Make sure the valves are set right. Another more advanced check is to pull an air box cover then rotate the engine until the rings are visible. You should notice an indented line in the compression rings. If not, they are worn out. I don't really recommend this check because the air box gaskets can be stubborn to clean up and they are in nasty places too.

As always, clean fuel filters, make sure the engine is getting fuel and no plugged intake lines, and make sure it is getting all the air it needs, so clean air filters and few bends in the intake piping. Good luck.

 

[walkerv]

The 1.484 is for advanced timed engines; usually turbos. It goes with having the idler gear advanced one tooth. The higher the injector is set, the sooner the rocker arm will depress it.

I am pretty sure there is a model and serial number on the block. Look for a flat machined spot; maybe above the oil cooler or on the top of the block behind the blower near the front of the flywheel housing.

A couple of things to check. Put a small screw driver in the rocker and injector arms and wiggle to check the bushing wear. If there is any play, they are shot. Make sure the valves are set right. Another more advanced check is to pull an air box cover then rotate the engine until the rings are visible. You should notice an indented line in the compression rings. If not, they are worn out. I don't really recommend this check because the air box gaskets can be stubborn to clean up and they are in nasty places too.

As always, clean fuel filters, make sure the engine is getting fuel and no plugged intake lines, and make sure it is getting all the air it needs, so clean air filters and few bends in the intake piping. Good luck.

I was doing some research on this also and found tons of variables on injector timing for the 8v92 I'm guessing the tags on the rocker covers must be long gone also , I'm not sure that a stamped model and serial number would give the op all the neccessary info but if it has stamped info in it then he is definatly going to have to contact MTU to help decipher it

 

[Former Wrench]

This should help. I hope I got the right page; if not I will reload.

 

[RZucker]

Serial number stamped on the block should be on the right hand rear side just under the last air box cover.
Should look like this: xxxx-xxxx
8vxxxxx

Lower number is the engine serial, the upper 8 are the arrangement number. At least on a V 71. I think the 92s are in the same spot.
Oops, too slow.

 

[Former Wrench]

When I downloaded the 92 info I got the same for 53,71,149, & 60 series too. If anyone needs any, give me a shout.

 

[kshansen]

The 1.484 is for advanced timed engines; usually turbos. It goes with having the idler gear advanced one tooth. The higher the injector is set, the sooner the rocker arm will depress it.

True in part but the higher it is set the more the plunger in the injector has to move to get to the point that the upper and lower ports in the injector bushing are both cover to start the injection.

I know in the V71 manual there is an explanation of how to determine if the timing is advanced or standard. In the V71 book it is shown in Section 1.7.1 and I would expect to find it in the same for the 92 series. It is the section of the manual that deals with the gear train. It involves finding top center on one cylinder then using this to compare the injector travel to a set of standards given in the book.

Not positive on the 92 series engines but on the V71 engines the Model and Serial numbers are stamped in the block between the air box covers below the head.

Edit I see formerwrench got the page out of a 92 manual so that should work better!

 

[Former Wrench]

Usually the turbos and big injector engines were A-timed. I have done a lot of them and one time I spent about 5 weeks at the Freightliner factory changing an order of 12V71 from standard to A timed. A big winery bought 60-70 new trucks and there were not enough A timed engines available so we had to play catch up and change them before they went to assembly.

It is a straight forward process. The cams are keyed so when they line up with each other the mark for the idler gear is in the right place. The holes in the crank gear are offset so it goes together one way. The idler has 3 marks; one for the crank, and the STD and A for the cams. There is an offset for the idler hub to set in and a little fitting for oil to the bearing so the idler is limited to where it lines up. With the cams aligned, the idler close but not installed, the crank can be barred for the marks to all line up.

There was a standing rule to have someone else take a look and verify the marks were aligned. Then the rear of the engine got buttoned up.

 

[ms0115]

First off, there are no numbers on the block. It was factory remained at one point. The tag was riveted to the block, still have rivets do not have tag. The company found some old paper work from DD that said the serial # 8FF5093 model # 8083 7400. The turbo had been replaced do to seal failure and made a mess of air flow through the cooler. I replaced the cooler, I have checked the piston rings and they looked good. ( Around 1,000 hours on a rebuild, then set for 2 years prior to coming to my shop for lack of power. Earlier I said the injectors ran out of stroke, I would like to clarify this statement). Valves down, injector up, set the injector to 1.484, rotate motor, when that injector is depressed, the motor will not turn through (bottoming out injector). Go to 1.600, the motor cranks and runs, ton of black smoke and does not want to achieve top rpm. I pulled the injectors today, 3 would not spray properly. This still does not explain not being able to set the timing according the book. Thanks for the help.

 

[ms0115]

First off, there are no numbers on the block. It was factory remaned. at one point. The tag was riveted to the block, still have rivets do not have tag. The company found some old paper work from DD that said the serial # 8FF5093 model # 8083 7400. The turbo had been replaced do to seal failure and made a mess of air flow through the cooler. I replaced the cooler, I have checked the piston rings and they looked good. ( Around 1,000 hours on a rebuild, then set for 2 years prior to coming to my shop for lack of power. Earlier I said the injectors ran out of stroke, I would like to clarify this statement). Valves down, injector up, set the injector to 1.484, rotate motor, when that injector is depressed, the motor will not turn through (bottoming out injector). Go to 1.600, the motor cranks and runs, ton of black smoke and does not want to achieve top rpm. I pulled the injectors today, 3 would not spray properly. This still does not explain not being able to set the timing according the book. Thanks for the help. Forgot to mention, they ran 9G85 injectors in this motor for years. When it started running low in power someone sold them on putting the 9290 injectors in. In this application, which should I go with?

 

[RZucker]

1.600? Does this thing have DDEC electronic injectors???

 

[ms0115]

No it has mechanical 9290's.

 

[RZucker]

Ok, Just asking. That !.60 just seem odd. I did some 92 tune ups years back and they were in the 1.4xx range, my tune up kit only goes to 1.50 and I didn't need any odd gauges. Your engine must have some wild cams.

 

[td25c]

Valves down, injector up, set the injector to 1.484, rotate motor, when that injector is depressed, the motor will not turn through (bottoming out injector). Go to 1.600, the motor cranks and runs, ton of black smoke and does not want to achieve top rpm. .

My 92 manual shows using the 1.600 timing tool with the 9290 injector .

As for the black smoke check the emergency shutdown flap at the blower intake , clogged air filter , collapsed air intake duct ,& turbo failure ( with the engine off make sure the turbo spins free by hand ). Black smoke is a sign you aint gettin enough air .

 

[ms0115]

I agree there must be something different about the cams. They were set at 1.600 when it got here, which is why I went back to it. Done a lot of 6-71 rebuilds and have never run into this before. Thanks for the help.