Overshot's Blog

[Rawze]

I absolutely hate to see anyone with that kind of troubles. This is an interesting thread though. You posted oil sample reports from all the way back since june of last year, and it had small hints of this sort of thing in it even back then, but everyone mostly missed it because it was so minor. Then in august, you posted this...

(08-22-2016 )overshot Wrote:  Yep, that's a possibility. But I'm loosing about a gallon of coolant per month (12000 miles). But that could partly be an external that I can't see ir find any sign of.
I'm at Mr. Hagg's so I'm sure we'll figure it out.
But I will still appreciate any and all feedback.
God bless cummins

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-- Who could have known, but a gallon per month is definitely concerning. It sounds like it finally got bad enough for someone to find. -- Totally sucks.

Those 2250's are notorious for #5 liner to leak.

Make sure you raise the liner height to 0.014" when it is re-built and that it is hand torqued, and that it sits over night, then re-torqued, etc. like suggested elsewhere on the forum.

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Mr. Hag has a brand new certified short-block in his shop right now that came straight from the warehouse that he is going to have to pull apart because the liners from factory are not correct. Some are 0.011" and some are 0.012" and a couple are 0.013". there are even differences from one side to the other on them. -- This came straight from factory. Must have been built on a friday night? -- Who knows, but it is considered "in spec" according to the book. I know I would not want it in my truck like it is though.

Do you think if that short-block had made it to a dealer, that they would have bothered to make it right before using it? -- Very Doubtful.

I say Cudos to Mr. Hag for checking, finding, and then taking action on this before it ended up in someones truck.

[Running rough]

It is of my opinion just because a guy is certified to weld or do whatever they are doing mechanics especially does not mean a guy who does not have the ticket like for instance most owner operaters, can't do the job better, who have they got worken at cummins these days, I am willing to bet only a small percentage do the job the way the customer would it to be done,

[Marajin]

Just some FYI>

On 2250 and 2350, A lot of guys that custom tune them turn off pulse injection for some fuel mileage gains. I see nothing much wrong with that in itself but with the pulse left on, an engine will always run a bit smoother.

Since they do have this ability then it can used to reduce vibration in the whole engine and that would include the liners. There is a fairly recent update on MM that I have seen being tested that does leave pulse on and uses it to reduce engine vibration as much as possible. I test drove one with it in and all I can say is d@#$m smooth. Seems to be even better than factory on smoothness I think.

Just letting everyone know that may be using that style of tuning. I tend to think that something like that would also help slow down the chance of having a liner issue in a higher hp engine in the long run. I guess the question now is how can it be done so that you dont take a fuel mileage hit for it.

[Running rough]

(01-22-2017 )Marajin Wrote:  Just some FYI>

On 2250 and 2350, A lot of guys that custom tune them turn off pulse injection for some fuel mileage gains. I see nothing much wrong with that in itself but with the pulse left on, an engine will always run a bit smoother.

Since they do have this ability then it can used to reduce vibration in the whole engine and that would include the liners. There is a fairly recent update on MM that I have seen being tested that does leave pulse on and uses it to reduce engine vibration as much as possible. I test drove one with it in and all I can say is d@#$m smooth. Seems to be even better than factory on smoothness I think.

Just letting everyone know that may be using that style of tuning. I tend to think that something like that would also help slow down the chance of having a liner issue in a higher hp engine in the long run. I guess the question now is how can it be done so that you dont take a fuel mileage hit for it.

That is certainly a good enough reason to leave it on but, does that mean carbon packing issues might come back to and what about egts and power loss, never mind the oil staying clean part

[Marajin]

(01-22-2017 )Running rough Wrote:  That is certainly a good enough reason to leave it on but, does that mean carbon packing issues might come back to and what about egts and power loss, never mind the oil staying clean part

Carbon packing issues are done by dirty combustion. Should not be problem the tune runs so clean any ways. EGT would slightly depend on how smooth you want to make it but it is timing and boost vs power that effect it the most. I think those can be tweaked to bring it back in spec pretty easily. Power loss should not be an issue at all because the ECM knows how to make proper power with it already. If anything then maybe it would be smoother more consistent power with less vibration and allow for even higher settings with less risk?. Seems reasonable.

Oil don't lie. Slightly lower efficiency in a tune made just for all high fuel mileage and not more power maybe someone would see slight difference but it still should not be going black again thou.

The one I drove, the the manifold temp was slight lower after test driving it than it was before the update. Hard to tell but was not different so much to notice. the truck had 575 hp in it and it was very smooth. had to watch speedo because it would get up to speed faster than expected.

[Running rough]

My 2250 has a pretty insane custom tune by Unilevers with a custom 871 turbo, I am not sure if a guy could implement pulse injection on jected up fuel settings, probly have to start with s stock file and go from there, also how would pulse injection work with spooling the bigger turbo, these are things that I am not sure of

[Marajin]

I looked inside the program and found that pulse was back on and injection timing was set closer to a qsk engine than a highway truck as well but had a curve in it for fuel mileage in lower to mid torque areas. One thing that I had to wrap my head around though is that some of the smoothing was achieved by lowering rail pressure slightly and making up for it by increasing fuel through the air-fuel-ratio settings instead. Makes for a slightly longer burn on the fuel making expansion not so sudden, harsh, and rapid on consecutive pulses. I think it even increases the power stroke slightly because of this due to it having a more consistent burn between pulses. The one I test drove seemed to respond better than I expected for a 575. The other guy I was with said "d@#mn this thing will get you a speeding ticket fast!". lol. It was definitely not lazy at all.

[Running rough]

And I will add to that, the drivability for pulling 140000 lbs even as low as 1300 just seems normal pulling on level ground and will maintain speed even up small inclines, of course I don't run it that low on a consistent basis, truck is geared 1400rpm @ 100 km an hour

[Running rough]

(01-22-2017 )Marajin Wrote:  I looked inside the program and found that pulse was back on and injection timing was set closer to a qsk engine than a highway truck as well but had a curve in it for fuel mileage in lower to mid torque areas. One thing that I had to wrap my head around though is that some of the smoothing was achieved by lowering rail pressure slightly and making up for it by increasing fuel through the air-fuel-ratio settings instead. Makes for a slightly longer burn on the fuel making expansion not so sudden, harsh, and rapid on consecutive pulses. I think it even increases the power stroke slightly because of this due to it having a more consistent burn between pulses. The one I test drove seemed to respond better than I expected for a 575. The other guy I was with said "d@#mn this thing will get you a speeding ticket fast!". lol. It was definitely not lazy at all.

There is a very real possibility that cummins engineers still have a lot to learn to get these commen rail engines tuned for apsalute peak efficiency and performance, I am sure you could bring some of your tuning know how to thier table