exhaust doser

[JasonH]

I have a deleted 2009 cm871 and the turbo locked up on it and I am replacing it with a turbo off of a 2013 cm2250 that I already had. I was told by a cummins tech that it would work but I'd have to change some plumbing which isn't a problem. my question is the fuel doser behind the turbo. it has a fuel line and two water lines going to it that after swapping turbos they don't line up. Can I delete them since my filter is hollowed out?

Also my oil return line is now too short to reach the turbo. I noticed steel braided hose on it, can that be cut off and extended with high pressure rubber hose and clamps? Not sure how much pressure should be on the oil return line.
THANK YOU IN ADVANCE

[Rawze]

- As far as the Doser pipe and connections, if it is de-mandated, they do not need to be hooked up, although the lines need to be dealt with, capped, bypassed, etc.

* Next, stop listening to the morons at the stealers$it... they are beyond clueless when it comes to questions like that!.

* Next, just because you have a 400-series turbo lying around does not mean you should be putting it onto your CM871. What engine ser# (ESN#), power settings of the engine, what type of trucking operations do you have, weights, average fuel economy per ifta quarter,... etc... because if you go about putting that 400 series turbo onto that engine that normally takes a 500 series turbo onto it, you could very well be shooting yourself in the foot. A 400-series turbo is quite a bit smaller and on a CM871, they will not be able to handle the same power capacity.

The quicker response of the 400 series turbo will mean a shortened engine life (from 800k miles down into the 600k mile expected range) for any power level much above about 450HP or 1750trq depending on truck gearing, type of operations, and how hard the thing is driven below 1500 rpm's.


I know you mentioned the return line but i am stating this about the high pressure side iof it between the oil filter housing and the turbo as a heads up ...

With regards to the oil pressure supply line .... It is ONE OF THE MOST CRITICAL OIL LINES ON THE ENTIRE ENGINE THAT IS EXTERNAL TO THE OIL PAN!!!! --- PERIOD!... and if that line were to leak or blow out on you, you can kiss that engine goodbye in a hurry!. That oil line is noting to play with there and has been the complete death of many engines that I have seen when it fails. It only takes about a minute or 2 and the slight hint of oil small in the cab of the truck after it pops ... and it is engine lock-up city if your climbing a hill or going down the roads at speed. By the time your oil light goes off and shutdown occurs, the engine usually cannot be saved after that line fails and no one catches it quick enough... JUST GIVING YOU THIS WARNING!.

-- NO .. YOU CANNOT USE A RUBBER HOSE OR PATCHED LINE TO EXTEND THE HIGH PRESSURE TURBO SUPPLY LINE ... IT TAKES A HIGH-TEMP BRAIDED STEEL HOSE DESIGNED FOR HIGH PRESSURE, HIGH TEMPS, HOT OIL TO GO THRU IT... ONLY A PROPER SOLUTION WOULD SUFFICE!. Find a correct length oil line (possibly the correct part# from a CM2350 in that same place) and use that instead.

- The return line that you mentioned is less critical, but you should be able to find the right part# off a 2350 for one that is the proper length so that it does not have to be patched. Any restriction in the return line at all and your turbo will bleed oil.


-- My advice... unless your a hyper-miler and don't give a damn about the power and performance of your truck.. are trying to down-size your turbo on purpose ... you would be far better off and less headaches, less problems, etc... by buying a reman turbo from YTS in griffin.GA for about half the price of the stealer$hits and offer them your good 400 series as a trade-in + the bad turbo you got. Maybe you get some more off the price,.. who knows, i cannot speak for them.

* Last but also foremost, Who did the delete programming? that is the biggest concern of them all. More engine destroying bad programs out there than a person can shake a stick at. As well, if the turbo is down-sized, it will require some ecm re-programming by someone who knows how to do this properly. Most of those garbage-can delete shops and the guy doing the programming for them, these guys are completely clueless and would not know where to start to even begin to get it right. That is the next challenge beyond any hardware mods, sacrifice in power and performances that would be necessary , etc..

Can it be done? -- Sure... Should it be done??? -- Not if all your trying to do is save some $$$. because it very well could you a lot more down the road. it would be like jumping over a dollar to save a dime. Somethng like this should only be considered if you have a specific need or purpose for it outside of simply trying to save a few bucks because what otherwise, your trying to do is going to change significantly how that engine runs and its programming needs. Just because you got a spare turbo laying around that is smaller than the one you have on there does not mean it needs to be slapped onto the side of you engine.

[JasonH]

my engine is ESN 79405155 and the turbo came off of ESN 79645840 both of which are 550's. Sorry about the strange messages I'm not very good with computers.

[Waterloo]

I spoke with Unilever about these smaller turbos on my 871, long story behind that one. Bottom line, it can be done, but like Rawze stated so succinctly, not worth the trouble or issues it will create. Best bet, call YTS Turbo down in Griffin GA and get the correct turbo for your motor. I run a YTS, no issues to date, been on there a couple of years, maybe more, knock on wood. And don't get me started on Cummins reman turbos, they are JUNK. See my signature below.

[Rawze]

(12-05-2020 )JasonH Wrote:  my engine is ESN 79405155 and the turbo came off of ESN 79645840 both of which are 550's. Sorry about the strange messages I'm not very good with computers.

It being a 550, that 400 series is going to be restrictive and run out of steam and have too high A/R ratio trying to make the 38 psi that CM871 needs to make a full 550 hp. It would do good to support 450HP or so and only 35~ psi or so boost before becoming restrictive on that older 871 engine. What you seem to not be accounting for is the fact that a CM2350 does not need but only 32-33 psi boost to make 600+ horsepower due to its much higher cylinder compression ratio vs. the 871. - That is why the turbo is so much smaller. .. those 2350s do not need that bigger 500-series on them to make the same power as the older 871's did.

You put that 400 series on there your going to have issues. Either your not going to have enough boost for the power it is making, and 33-35 psi is going to make EGT's too high and cook that turbo ... or if you force its vanes closed more to make the 38+ required, then it will be restrictive at this high pressure and the engine is going to have higher than normal back-pressure on the exhaust manifold. This makes for more heat in the cylinders, it will labour against the higher than normal exhaust, taking power away from the flywheel. 37~38+ psi boost on a 400 series will also end up over-spooling that turbo for it to make it, killing the turbo after a while and or causing excess heat in the cylinders putting it at risk to crack a piston. -- That is what is going to be the result. The A/R of those 400 series turbos does well to keep after 33-maybe 34 psi boost on the isx. This is fine for a higher hp high compression ratio 2350 but not so good for higher HP on older engines.


If the engine were set down at 450HP, maybe 1650 torque, you could get away with about 34-35 psi boost and EGT's not be excessive. It would be in the ball-park range with it on the 871 ... Otherwise it is going to have issues.


Next Q. is WHY did the other turbo go out to begin with? -- Bad delete programming is notorious for shortening the life of the turbo significantly as well as the engine.

[JasonH]

Not sure why it went bad but it seems to have bent the shaft no oil or coolant restrictions . As far as the boost its never gotten over 30psi boost in the two years I've owned it. I was told that these motors don't build over 30psi as they wont take it so I figured it to be normal. Same with The oil pressure being low at 25-28 psi at highway speeds. The oil pressure is the same as it was prior to rebuild and yes I put a new oil pump on it. All work was done by a local shop that several local friends/owner/ops sent me to. Every time I mention oil pressure to anyone I get the same answers (its a cummins they run low oil pressure). I run Mobile Delvac 15w40 and Fleet guard filters NO Lucas but I do add motorkote every other oil change.

I'm a detroit 12.7 guy this is the first ISX I've owned. I've always owned older trucks and done my own work but these things scare me to death.

[Rawze]

(12-06-2020 )JasonH Wrote:  Not sure why it went bad but it seems to have bent the shaft no oil or coolant restrictions . As far as the boost its never gotten over 30psi boost in the two years I've owned it. I was told that these motors don't build over 30psi as they wont take it so I figured it to be normal. Same with The oil pressure being low at 25-28 psi at highway speeds. The oil pressure is the same as it was prior to rebuild and yes I put a new oil pump on it. All work was done by a local shop that several local friends/owner/ops sent me to. Every time I mention oil pressure to anyone I get the same answers (its a cummins they run low oil pressure). I run Mobile Delvac 15w40 and Fleet guard filters NO Lucas but I do add motorkote every other oil change.

I'm a detroit 12.7 guy this is the first ISX I've owned. I've always owned older trucks and done my own work but these things scare me to death.

I don't know what kind of gaggle of complete idiots and morons you have been hanging around but they seem to be completely clueless towards the ISX 871 engine... I would have run like hel#ll away from those people if they had said those things to me.


- The ISX should have in the range of about 33 - 38 psi oil pressures at highway speeds when going down the road (most fall into the 34-36 range) and the engine fully warmed up with an unmodified oil pump. If your only getting 25-28 psi something is very wrong with that engine somewhere. Even under a hard pull and oil is running 230+ because of tortuous conditions, it should still be up at 33+ psi unless your idling. - only 30 psi when going down the roads is starting to starve the top-end of oil... i can only imagine how bad it would be at 25 psi and trying to climb a hill.


- The proper boost pressure at 500 HP should be every bit of 37,38 psi ... 39 is the high end and 40+ will kill the engine. Anything less than 37 or so at 550hp output is going to result in cooking that turbo and have excessive egt's.

As far as lower than normal boost goes, it could be any given number of reasons. Bad delete programming where the engine is permanently stuck in a silent derate because no one bothered to re-program the engine mode control or other short-comings that god knows what someone did or did not do properly... That type of crap programming is a plague and is everywhere...no more check engine lights any more, but the ecm is screaming its arsse off internally and derating because all the fault codes are blocked form being able to show up in the dash instead of someone doing a proper job in it.

Could also be CAC leaky, when is the last time you pressure tested the entire engine?.. Pressurized the entire intake with 30 psi air and checked everything for boost leaks?.. NOT just the CAC unit, but the entire intake?

- Next, now this brings up,... what someone did to the hardware... Did they drill a few holes in the DPF and not hollow it out completely?- this causes exhaust restrictions and the turbo suffers greatly because of it... Did they use any block plates anywhere? -=- and where did they do this? --- did they remove the EGR cooler?-- or block coolant flow thru it?-- This is a big no-no for that model engine... Like i said.. bad delete everywhere for these ISX's ... brain and engine butchers around every street corner who want to rip you off in return for something you could have done yourself for free.. and properly.

-- Sounds to me like you have had some serious morons telling you what to do with that engine and how it should be run.. Around here, I don't tolerate bad or mis-leading information and it sounds exactly like you have been caught up into just that .. a bunch of garbage info.


As far as the lower than normal oil pressure goes ... Make sure your pressure gauge is accurate. If it is genuinely only making 28 or so psi going down the roads after it is fully warmed up, you have some very serious issues that need to be addressed right away. Your oil temps should be about 218~ish when normally going down the roads F to 230 on the high end when pulling hard. 240+ is too high and something is wrong... either with the programming (bad deletes will often make oil temps run higher than normal) or you have issues internally. Here is some related discussions on lower than normal oil pressures after some shop inframes the engine and don't know what the he#ll they are doing: http://rawze.com/forums/showthread.php?t...5#pid32065


what is the oil pressure when it first cranks on a cold morning? what is the oil pressures at idle?

how many miles are on it? - has it been inframed? -- some more history would help.

That SIX ain't no 12.7 Detroit... learn how to care for it properly, learn how to drive it properly, and learn to regularly wrench and maintain it properly ... it will be good to you in return. Anything less and your just wasiting your time and mine by me trying to help you.

[JasonH]

I do appreciate the info greatly and I'm learning as I go.
It has approximately 140k since the inframe
oil pressure at cold start is at 38-39psi
at idle 700 rpm is 20 psi
I haven't pressure tested the intake system but when cleaning the oil out of it this week I have found 2 small leaks in the CAC itself and once I get everything back together I will pressure test the whole system.

Maybe after the first of the year I can make an appointment to bring it to ya and we can go over it together since I don't have anyone trust worthy around here. This way we can see what exactly has been done to it. Starting to think I should have stuck with my old 94 instead of buying a newer truck lol.

Thanks again.

[Waterloo]

Those pressures do not sound normal, the CAC, if it is leaking, you will need to replace with an OEM unit. Do not go aftermarket in regards to the CAC, as the air volumes will not be correct and you can do damage to the turbo and in most all cases, you will lose fuel economy.

I will send you some links... Mainly the correct 871 programming for your motor.

You will need an inline 6 reader, which can be purchased on eBay, the Chinese one, around $200 - $300, which is what most all of us use here.

Check your mail.