Have an odd issue with a freshly rebuilt Detroit 92 series. It is connected to a fire water pump and ran at 2085 RPM for proper GPM’s. For whatever reason the intake temp on the blower is 350’F-380’F and exhaust temps are tapping the door at 900’F. Engine coolant temp is 180’F. I’ve removed intake and exhaust to ensure proper air flow with no change thinking there was a blockage. Any ideas on what is causing this?
What injectors does it have and what timing height was set?
This I don’t know since I did not rebuild it. I’m assuming stock since it is not a required higher than stock HP engine. The blower and turbo intake are discolored from excessive heat.
Who built the engine?
Company called Mid Coast Diesel out of South Texas. They have a tech who is coming out to look at it tomorrow, but he doesn’t know what it could be either.
You are leaving out some vital information. Where is the intake air coming from, if inside air how far from the exhaust/turbo. Ambient outside air temp possibly minus a degree or so due to pressure drops would be normal. If this is the style with the air cleaner on top of the engine the can has air openings and it may be turned wrong. Is it turbocharged which I suspect it is, does it have an aftercooler (after market not beneath the blower)?
The engine builds for Detroit are numerous. Turbo engines have retarded timing set in the geartrain and will use lower cfm injectors at a specific timing height for the type of injector. I would be checking whether it has the correct timing set up, the correct injectors, and the correct injector timing.
I know what your asking, but the issue is we have a sister pump set up in the exact same figuration next to it that does not have this problem. It is turbocharged that feeds directly into the blower.
All of this could cause higher than normal air intake temperatures? I would think engine coolant temps could then also be affected.
I’ll try and get a picture of the configuration so you get an idea of what we have.
Are you where you can take some pics? Ide like to know where the intake temp sensor is located. Have the temps been verified using another source? The coolant temp would be much higher than 180
The temps are taken with a hand held temp gun. I’ll get pictures in a bit. Heading back over there.
Also....is this a 6V92T?
8V92
Get a pic of the engine panel too
This is the sister engine, same configuration as the other engine in question.
When it comes to pressure and temperature readings, I always make sure the instrument used is measuring accurately. Did you ever check those readings before the rebuild? Under a heavy load the egt doesn't look to far off. The paint on the blower sure shows high temp conditions, that turbo blanket will help hold the heat.
Why is the intake hose and PASS just hanging free?
Biggest concern for Housed engines is the availability for Outside Air thru shutters or damper systems and fans, Intake air is usually supplied thru a IN ROOM air filtration system where the room supply air could be the problem here. Blower has no way to generate enough heat to cook the paint as shown unless supplied air is cooking. Is the Cooling System fan Pulling or Pushing air? Should be Pushing to OUTSIDE drawing more Fresh Air in thru engine side dampers and not across radiator into room.
1. I'm not seeing an inlet air temp gauge on the panel........so where is that temp being taken with the IR gun? 2. There is also not a pyrometer on the panel........is that temp being taken off the hot housing with the IR gun? 3. How is the engine performing when running and loaded? Is there black smoke out the exhaust? 4. I am not familiar with whatever set up that is on the air intake hose. What does that look like inside that hose? 5. Has the fuel consumption been in range of the other engine, or has it been run long enough to tell? 6. Was the turbo replaced also? 7. Was the loaded high-speed set with the governor adjustment? 8. Is the turbo whining under full speed? 9. Are the airbox drains fully cleared and have boost air coming through them? 10. Has the intake hose been removed between the turbo and the blower to check for exhaust soot? It looks like the air is super-heating in the turb. The blower is discoloring because of it. If this engine is running at full speed loaded for extended time the turbo will heat more than normal due to the load alone........it's basically busting its ass. As of this moment, I'm looking at the fueling set-up or the turbo as being an issue.
Judging from the discolored paint, I'd say the blower seals are not long for this world. My thoughts are along the lines posted above. Just rebuilt engine indicates issues in the rebuild. Cam timing being foremost, injector sizes and timing being next but I would check all the intake piping first to make sure the engine is getting enough air in the first place. Most interior mounted engines I've worked with had suction disks installed in the air piping so building air could be pulled if the outside airflow became restricted.
It would be helpful to see color of turbo exhaust compressor housing. IMO-three things to cause that, restricted air, timing, over fuel, or a combination of all three. Many a Cummins with burned paint on after cooler leads to those three things. 2 cents.
With the mention of over fueling, excess fueling means more heat. You said 900 for egt? Most 4 strokes are in the 1200 range. The main place I see heat here is all the exhaust wrapping, I don't think any of that is necessary on this engine, it is not running down a race course. I'm guessing it is an intermittent application not like a constant running genset. Where did you check the egt at? Maybe that turbo is cooking hot from the not radiated egt's. Just a stupid me guess. This is one of those things where a person needs to be at the engine to rule things out. Air intake restriction? You can use a vacuum gauge pre turbo to check for that. Please keep us posted on the findings. Lots of good info here from everyone. PS. I'm thinking after seeing the photos again, the egt must not have been measured accurately, it must be higher, its very hot under that exhaust turbine section, hot turbo, hot intake side. Is that thing on the intake an emergency air shut off?
The insulation on the exhaust is called lagging and it has been a requirement on all the enclosed gen sets I have been associated with.
What pray tell is a low cfm injector? Bob
I forget what the numbers on the injectors actually stood for but suspect CCs is probably closer to reality. I've worked with S, SV and N series nozzles in 65 and 90 capacities. I would imagine that a 92 series engine would use something in the order of a 100 or 120 size but really don't know anymore. I've only run a top end on a green block 92 way back when. Done lots engines with N90 injectors on boats and N65 injectors on skidders and Drotts as well as trash pumps.
Was thinking back, the ONLY time I ever saw a DD engine that had burned the paint off a blower was it had run BACKWARD, also set fire to the air cleaner element.
Running backwards is easy to do in a dump truck.
Most 92's that I worked on and that was in the 80's had 90's for stock injector.
@Nige……..come get your gf.
Yeah blower suction in reverse, didn't think of that one. I wonder if the fire pump would work in reverse? Though the egt would have been pretty cold while doing that.
Centrifugal pump will still pump just LOW Volume and Pressure.
Depends on the type of impeller for the pump. A trash pump with straight vanes will still put out. A pressure pump with curved vanes I wouldn't think would do much at all. I've had it happen on a couple of boats that had wet exhausts. You grab for that shut down real fast when you realize what is going on.
Yeah, sucking water into a Cylinder is REALLY Bad!!
It was salt water as well.