Piston Rings Worn Out, Time for a Rebuild

[74M35A2]

An injector can be serviced for the most part. If the nozzle is dirty, it can be cleaned ultrasonically. If a nozzle is leaking, it can be lapped back into shape with the pintle and lapping compound. I had Superior Diesel in Detroit do this for me on 3 Bosch (Zexel division in Japan) injectors I had on a Kubota diesel light tower that would not run correctly. Ran perfect after that.

 

[scboolitcaster]

Sweet, another use for my ultrasonic cleaner!

Sent from my SAMSUNG-SM-G930A using Tapatalk

 

[mark salanco]

I have the screw adjustable style, it takes an Allen key. The new style takes a flat head screwdriver.

 

[mark salanco]

Just ordered 6 new injectors from Memphis Equipment. $54 n change per injector. They are the single hole injectors used in the LDS-465-1A engines. Thought I'd go with those, seeing that I have the LDS pump, pistons and rockers.

 

[Wildchild467]

I went through some injectors back in the day pop testing them to calibrate them. you get them once in a while that leak a little and what not. Personally, I would still pop test the new injectors just so you know they are exactly what you want and that they are all balanced. I have a set of injectors in my deuce now that pop off beautiful and it starts and runs smooth. I think adjusting valves along with good injectors is what really tunes these trucks up.

 

[mark salanco]

I cleaned and pop tested my original injectors. I thought they were good, but after installing one new injector, I realized how bad they are. The didn't leak, but the spray pattern and even the sound of them was way different than the new injector. Like I said before, when I cracked the injector line on each injector, not much of a noticeable difference until I cracked the line on the new injector, it was like pulling a plug wire off a straight six .

 

[mark salanco]

Well, the new LDS one hole injectors came today. I decided to pop test them, and make sure they all are within range. Opened the first box, and the nozzle was covered in varnish. It did not pop, I took it apart and soaked it in carburetor cleaner. Had a hard time getting the needle out of the nozzle. So all of them are getting a good cleaning.
The one I did clean, pop tested great, nice crisp clean pops. Set it to 3050.

 

[mark salanco]

I installed 5 of the new LDS single hole injectors today, had one bad one. The 6th injector is a new 2 hole. This is a total different sounding engine now. It has a lope to it at idle. It's definitely hitting on all 6 cylinders now. Every injector line I cracked, gave a big response. I'll test drive it again when I get the brakes back on the rear.

 

[o1951]

Just ordered 6 new injectors from Memphis Equipment. $54 n change per injector. They are the single hole injectors used in the LDS-465-1A engines. Thought I'd go with those, seeing that I have the LDS pump, pistons and rockers.

Mark, I have been following from beginning and am confused. You say 6 NEW injectors, but what you got appears to be well used.
"Opened the first box, and the nozzle was covered in varnish. It did not pop, I took it apart and soaked it in carburetor cleaner. Had a hard time getting the needle out of the nozzle. So all of them are getting a good cleaning."

 

[mark salanco]

The injectors are new rebuilt units. They have all new parts inside, new springs, plunger rod, nozzles and needles. They apparently have been setting on a shelf for several years, when they are rebuilt, they are oiled.
The oil turns to varnish over several years, like a carburetor will do. The LDS injectors don't sell like the others. On a good note, Memphis Equipment is sending me another rebuilt injector, free of charge. They did apologize for the condition they were in.

 

[Wildchild467]

I installed 5 of the new LDS single hole injectors today, had one bad one. The 6th injector is a new 2 hole. This is a total different sounding engine now. It has a lope to it at idle. It's definitely hitting on all 6 cylinders now. Every injector line I cracked, gave a big response. I'll test drive it again when I get the brakes back on the rear.

I have an LDS in my M109A3 and that sounds completely different than my M35A2. I think that could be why. The rocker arms are the same on both engine (I verified it).

 

[Wildchild467]

The injectors are new rebuilt units. They have all new parts inside, new springs, plunger rod, nozzles and needles. They apparently have been setting on a shelf for several years, when they are rebuilt, they are oiled.
The oil turns to varnish over several years, like a carburetor will do. The LDS injectors don't sell like the others. On a good note, Memphis Equipment is sending me another rebuilt injector, free of charge. They did apologize for the condition they were in.

Im glad to see they are taking care of you with the injectors. Stories like this are good and only helps a vendor build a good reputation.

This is why I always like to check parts that I get like that. you never know what stuff you may get and its always good to know what parts are like that go in your engine. take measurements and make sure things are in spec. Keep up the good work and thank you for updates!

 

[DavidWymore]

ONLY in the intake rockers are different, or both?

Thanks

 

[mark salanco]

Just the intake rockers are different. I bought the intake rockers from
WBParts.com
Part number 11641735
NSN 2815-00-178-1184

 

[mark salanco]

The intake rockers are way different. The geometry is where they are different.
The angle that the pushrod contacts the lifter is way different.
I measured both rockers, using 123 blocks and precision brown n sharp feller gages. I have the results written down somewhere.

 

[mark salanco]

I finished the brakes on the rear today, put a new intake manifold heater on, this one works..lol.
Also put a fuel pressure gauge in the filter housing. 35 at idle and 75 psi at 2400. Only 2 pounds with just the lift pump, time to change the filters. I had put a new fuel tank, pump and sending unit in last fall. I had about 15 gallons of used waste oil and fuel in the tank, so during the engine rebuild I drained it out. I was surprised by how much sludge was in it. I put 15 gallons of fresh diesel fuel in it, changed all the fuel filters. I disconnected the fuel line going to the injector pump, attached 3/8 rubber fuel line to it, and ran it back to the fuel tank, I let the pump run for about 45 minutes. Then I disconnected the out put line of the final filter and ran that back to the tank, ran that for 1.5 hours. So I'm pretty sure it's time for new filters. I took the truck on about a 40 mile drive today, I ended up turning the fuel up about 8 flats. Drove it hard, almost wide open most of the time. The power level is almost what the LDT was when I first got the truck. My boost will max at 15 psi. When I got home from the drive , I let it idle and looked at the slobber tube, hardly anything coming out of it. So far I'm pleased with the results. I'll get new filters Monday or Tuesday, then take another drive and see if that makes a difference, then retorque the heads.

 

[mark salanco]

Download and read this info.
It about piston cooling using oil jets , such as the multifuel has.

https://www.researchgate.net/public...ng_using_oil_jet_in_heavy_duty_diesel_engines

 

[rustystud]

Download and read this info.
It about piston cooling using oil jets , such as the multifuel has.

https://www.researchgate.net/public...ng_using_oil_jet_in_heavy_duty_diesel_engines

The MAN engines the Transit Department I worked at had the cooling passages in the pistons and oil jets aiming the oil into them. I wished I had saved some to show everyone. I cut one in half to check out the passages.

 

[mark salanco]

After reading this, it makes me think that 1,200 EGT isn't going to hurt the pistons, the oil is pulling most of the heat out of it.
I had the old pistons running at 1,400 EGT and not one sign of them melting or pitting.

 

[DavidWymore]

On the same note, I just talked to a guy the other day who melted his LDT pistons at 1600.