Cummins 855 questions

[56wrench]

You guys down there must do things different. Years ago i bought a 534 ford natural gas engine that was pulled out of a pumping station. It was from the back-up emergency water pump. It was a small city and it was re-powered with a cummins, maybe an 8.3 if i remember correctly. I then turned around and sold it to the small town where i used to live for their emergency water pump which was an identical 534 that was starting to have a couple minor issues. It was an 'installed and running' agreement and i made a few thousand dollars from that deal. Worked great for a few years until their brain-dead-kid operator watched it get hot after it blew a heat-exchanger hose while running flat-out under full load. He called his supervisor and asked what to do. The guy screamed back 'shut it down you moron' with a few expletives thrown in. Then they got me to pull the heads off the original engine which was now the spare, got them freshened up, and swap them onto the one that i had sold them. That poor old 534 had run so hot it had started to burn the paint on the sides of the block. It seemed to run ok again and was still running years later. I gained some respect for the old 534's after that. Maybe the difference in this case was that it was part of a municipal water supply emergency system and not a stand-alone, fire-only pump

 

[RenoHuskerDu]

You guys down there must do things different. SNIP

Yep. The point of all this federal crap is to make us all do the same thing nationwide. Got your own local best practices honed over time, tested and true? Sorry, feds want y'all to do it the Washington DC way now. Makes it easier for feds to swoop in and take over. They tried when we had a little tornado last year. Sheriff told them to pound sand. They called it straight line wind so they wouldn't have to open their coffers and help with money to victims. Nothing fed is good anymore.

 

[Mike L]

So the machine shop deal fell through. Said he had the tooling to do a 250 but the 220 was different. How hard can it be to change them? The heads are off and easy to get to. Years ago I remember having to change injector cups in an ancient cummins in a Michigan loader. I greased up a tap, threaded the hole, used some sort of puller and yanked them. Then IIRC I froze the new cups, put some green bearing Mount on them, and used a tool to drive them in.

 

[DMiller]

Do not know where he gets that a 250 and 220 are Different. Most all engines are using Top Stops for Mechanical where the old series are no longer rebuilt. ALL used the same Cups.

 

[Mike L]

So the original machine shop told me the cups (he called them tubes in the head which throws up a caution flag) were larger than normal and he didn’t have the tooling. I honestly don’t know one from another but everyone make it sound like rocket surgery. They’re injector cups for crying out loud! It shouldn’t be so difficult.

 

[Truck Shop]

There called injector sleeves/coppers. Cups are inside injectors. Problem is 90% of the old diesel machine
guys have vanished. Anything below a Big Cam and your almost out of luck, And even BC's are getting
hard to find parts for, Most of the blocks have reached the end of machinable life, Cat the same way.

Call Diesel Cast West and get it over with.

 

[Bluox]

So the original machine shop told me the cups (he called them tubes in the head which throws up a caution flag) were larger than normal and he didn’t have the tooling. I honestly don’t know one from another but everyone make it sound like rocket surgery. They’re injector cups for crying out loud! It shouldn’t be so difficult.

Injector cups are the part that holds the nozzle on the injector and the part I think you are looking for is called an injector sleeve or more common a copper.
Driving in the sleeve is just the first step ,then the tip is set the top rolled in and the depth set by reaming the sleeve .
And truck shop was quicker.
Bob

 

[Truck Shop]

One thing to do is dry fit the liners {without o-rings} to check liner protrusion. After market liners vary
up to .0015 on liner flange thickness. So move them around and mark them-.003 to .006 liner protrusion.
I use a depth mic on the counter bores then install in best option.

 

[JLarson]

I second Diesel Cast West, also Industrial Diesel in Tx might be a try too.


The fire pump engine thing has been a thing for a while, anywhere that has adopted NFPA 20 is gonna want to see a UL listed engine.

 

[DMiller]

Times are swinging hard the other way where manufacturers and suppliers do not want nor care to do the expense of certifications, so they could care less of NFPA Insurers or anyone else telling consumer they Require such cert. In the Nuke world was a required “N” stamp with associated paperwork ore to finish product heritage, that no longer happens either so where the certifiers draw their lines in the dirt the others are walking the other way. Do not see it changing up soon either.

 

[mekanik]

The injector sleeves are different. The H and NH series used flanged injectors.
The hold down flange was part of the injector. The sleeves are installed in the
head and a special bolt goes through the hole where the injector cup would go
the bolt is torqued to 50 ft lbs then the manual says to give the bolt two solid hits
with a hammer then re-torque the bolt. Then the top of the sleeve is rolled with a
special tool. The tool for the NH series is different then the NT series. I suspect
that is what the problem is.

The tools below are for the NT series. I rescued them from being thrown away in a shop move.
The H/NH series roller is slightly larger if I remember correctly.

 

[DMiller]

Next move could be to Update the Heads.

 

[mekanik]

Update the heads?
If you search long and hard you might find someone with the tooling.
When I saved the tooling in the above post the NH/H tooling was there as well
but I did not bother saving them as the NH/H was obsolete and parts were
difficult to get and that was in the late 1980s.

 

[DMiller]

Either have to Update the heads to a more current injector design or replace the entire engine assembly. Finding Tooling is only part of it, then find Obsolete Coppers, then find someone that has installed them and succeeded in No leakers for the minimal Obsolete Coppers that can be found. Update is about The ONLY way to repair what is there or Start from Scratch and pay the Piper.

 

[Truck Shop]

The reason I keep bringing up Diesel Cast West in Portland Ore is it used to be called Northwest Motor Weld.
It was bought out/taken over some years back by Middle Distributors in Texas. When it was taken over the
old crew stayed and most of them are still there. I was on the phone ordering some con rods a few weeks
back and the lady I was talking to has been there for 35 plus years. She knows her sh!t by the way.

 

[Bluox]

The reason I keep bringing up Diesel Cast West in Portland Ore is it used to be called Northwest Motor Weld.
It was bought out/taken over some years back by Middle Distributors in Texas. When it was taken over the
old crew stayed and most of them are still there. I was on the phone ordering some con rods a few weeks
back and the lady I was talking to has been there for 35 plus years. She knows her sh!t by the way.

About 10 years ago I hauled a head to the Portland store and bet I met that woman .
I can't remember her name but she is a good looking red head.
And your right she knew all about that outfit and what they sold.
The last time I dealt with them I had a outside salesman wanted to choke him before it was over.
All in all, everything I got from them worked.
Bob

 

[terex herder]

If necessary, freight on 3 used, unknown heads would be manageable.

 

[Bluox]

Before someone get their panties in a knot this information is to educate not bad mouth.
I had to find my old H-NH Cummins shop manual I bought while I was in school 50 some years ago and it cost $4.50 in the 60s.
This covered 3 different engine series.
these are 6 cyl engines naturally aspirated .
NH 180 4 7/8 x6 672 cu. in. 6 bolt 2cyl. head flanged injectors external fuel lines. 4 valves.
NH 220 5 1/8 x6 743 cu. in. same type heads
NH 250 5 1/2 x 6 855 cu.in. 12 bolt 2 cyl head cylindrical injectors with O-rings internal fuel passages in head.
the 2 smaller ones could have 2 valve heads.
Could be turbo charged or supercharged.
the 2 bigger could be had in 4 cyl. motors.
The 5 1/2 motor was 4 valve and could be turbo charged.
HP ran from 118 to 400.
They all used the PT fuel pump.
Copper sizes are different for flanged or cylindrical injectors.

Bob

 

[Truck Shop]

All good stuff, did you happen to see the bolt torque for the 6 bolt head--Bob.

Also there is nothing about a old Cummins that's written in stone, Cummins had a tendency of
throwing parts in all sorts of cpl's and before cpl's existed.

 

[Mike L]

Probably a dumb question but is the cpl like an arrangement number? I’m going to call diesel west in the morning. They claim they can fix anything and it also shows a number for reman heads.