RTV1100-motor is done

6

6mmrem

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So my motor gave up on me,2011 rtv100. I bought it with 50 hours. It now has 2610 hours in 4 years. Been running a turbo kit on it for 3.5 years. !one piston has a hole in it and the other 2 are cracked. It hasnt had alot of cold starts either.using a block heater and a stick on oil pan heater. Any others out ther with these issues? Its a work horse on the farm, runs every day.
 
If the piston has a "burned" hole thru the top it's fuel/air delivery problems. Created too much heat.

Anxious to hear other details and opinions. I'm considering adding a turbo.
 
Piston pic

Here a picture of hole. Does this look like burn hole
 

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Yep. Appears to be heat stressed. That spot on the piston actually tried to melt.

When you installed the turbo kit did you also do the fuel adjustment and timing modifications??
 
you folks with turbos might need a pyrometer? looks like the damage i used to see when we turned a 220 cummins into a 262 with out piston cooling jets. I had a stack mirror so i could see the flame and back out of it if needed.
 
ovrszd said:
Yep. Appears to be heat stressed. That spot on the piston actually tried to melt.

When you installed the turbo kit did you also do the fuel adjustment and timing modifications??
Click to expand...


X2. If you did mess with fuel delivery setting, how much did you? Did it smoke much? Or run hot when working it?
 
I did the settings as stated in the turbo install instructions. It would run hotter than normal. If travelling uphill on back roads for extended periods of time, it might reach 3/4 mark on gauge. What exhaust temp was I don't know.
 
I'd be curious to see the Kubota data on fuel/timing/injector size for their turbo setups? How do they control this issue?

I'm afraid without some controls in place you will eventually have some type of failure.

Authurs example is a classic.
 
I've been worried about this situation since I started reading about after market turbos or even Kubota turbos... I have seen a lot of messed up pickup trucks where people fiddled with or added turbos or messed with the transmission brain. Looks like asking for trouble to me. I'll run mine as designed, hopefully it will outlast me.
 
just install a pyrometer after the turbo and if the temp gets above 1300 degrees for more than ten or fifteen seconds just back out of the throttle
 
If mine goes back together with a turbo, I'll be adding a pyrometer. Just to keep an eye on things. Might have to back off the boost come summertime.
 
I wonder if you could find some different pistons with heat plugs in them to help with the extra heat from the turbo. doesn't Kubota make a turbo version of this engine for another application?
 
Put the pyrometer between turbo and manifold. If you put it after, it can be +-300° difference... I believe aluminum starts melting at 1250°. Imho, I always say anything over 1300 for an extended time is considered hostile territory. Stuff is gonna start melting... after you turned it up according to the instructions, how much more did it smoke?
 
if you put the pyrometer between the turbo and the manifold you won't be able to monitor the temp of the turbo as accurately. most turbo equipped engines usually start to alarm around 1300 degrees after the turbo,but this engine doesn't have piston cooling jets or heat plugs in the pistons so a lower temp might be in order. I agree with bigredgoat these pistons will melt at a lower temp than pistons design for turbo applications. also note that the temp only rises in a lugging condition so the addition of a pyrometer will aid the operator to change driving habits to accommodate the load.
 
I'm curious about that as well.

I also understand that operator uses and habits have a huge impact.

I agree that a pyro would help the operator avoid problems before they happen.
 
some fun reading on pistons http://www.themusclecarguy.net/forged-versus-cast-pistons/

http://www.cumminsforum.com/forum/98-5-02-powertrain/623882-piston-meltdown-temp.html

http://www.trucktrend.com/how-to/expert-advice/1007dp-the-truth-about-egt/

this agrees with my experience years ago with the 262 cummins engine. the pyrometer in the beggining was in front of the turbo"in the manifold to be exact" and the temp would be all over the place changing so fast it was hard to read. when i put it after the turbo,although it read much cooler the temp fluctuations were gone. this made driving much easier and all i had to do was compensate for the temp loss over the turbo. in the old 262 i had no intercooler or aftercooler or even piston jets so i had to be real careful not to melt the pistons. i would reach 1400 degrees very often but only for a few seconds before i changed gears or throttle or both. the pistons could hold at very high temps but not for a long duration and the EGT would drop very rapidly with very little throttle adjustment. so for us RTV folks it could be driving habits gear selection and load that makes or breaks in this situation.
 
aurthuritis said:
if you put the pyrometer between the turbo and the manifold you won't be able to monitor the temp of the turbo as accurately. most turbo equipped engines usually start to alarm around 1300 degrees after the turbo,but this engine doesn't have piston cooling jets or heat plugs in the pistons so a lower temp might be in order. I agree with bigredgoat these pistons will melt at a lower temp than pistons design for turbo applications. also note that the temp only rises in a lugging condition so the addition of a pyrometer will aid the operator to change driving habits to accommodate the load.
Click to expand...

But the temp of the turbo is useless... No matter how hot it gets, that will not directly impact the cylinder temp. Cylinder temp is what made the piston melt. And that's what needs to be monitored. And the easiest place for that is in the exhaust manifold right before the turbo. If your at 1400° post turbo, that's at least 1700° pre turbo, which is the closet to true cylinder temp that you can obtain. I still want to turbo my rtv, just got to be super careful with the fuel....
 
BIGREDGOAT said:
But the temp of the turbo is useless... No matter how hot it gets, that will not directly impact the cylinder temp. Cylinder temp is what made the piston melt. And that's what needs to be monitored. And the easiest place for that is in the exhaust manifold right before the turbo. If your at 1400° post turbo, that's at least 1700° pre turbo, which is the closet to true cylinder temp that you can obtain. I still want to turbo my rtv, just got to be super careful with the fuel....
Click to expand...

I agree with what you are saying. But in Aurthur's case he got unreliable readings pre turbo. I agree that the actual temps might not be accurate post turbo. But by simply taking that into account, as in your reference of 1400 degrees post turbo actually being 1700 degree pre turbo, couldn't this still be valid info? And if stability is gained in the readings wouldn't that be the best solution?
 
actually the EGT post turbo is important because it is easier to melt the turbo than the pistons,at least in a normal situation. also it is easier to fit the probe in the exhaust rather in the manifold, especially in these small engines. put that aside and bigredgoat is correct in that the cyl temp or really the flame duration is what melts the piston. but in my experience the post turbo information can be reliably used to prevent failure. now the real question is??? can the stock piston hold up to intermittent temps of 1200 degrees?
 
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