Piston Rings Worn Out, Time for a Rebuild

[mark salanco]

Well 1600 seems a little excessive. .lol did he not know any better, or was he seeing how far he could push it?

 

[DavidWymore]

Well 1600 seems a little excessive. .lol did he not know any better, or was he seeing how far he could push it?

Yes...he didn't say.


I used to peg my Cummins 5.9 for short periods (big sand dune climbs) and never had a problem (related to heat anyway) but it would be nice to have some way to monitor actual piston temp so that we would really know how much we can push it and for how long.

 

[Wildchild467]

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.

How does it start when it is cold? Mine was a bear to start when it was cold (60 degrees F) when I had those new style LDS pistons. Right now with my OEM LDT pistons, my boost can barely hit 17psi and the EGTs never get about 1000 empty. I tried and had a little hill and it just didn't get above 1000 and max RPM of 2300. Before when i had the 15psi gauge i could peg that in a hurry as well with those "new style LDS Pistons" but the EGTs would be really high (1200ish).

Here is a test... how are your EGTs when you are just driving down the highway? I noticed that mine are a lot lower now than what they used to be. Lower EGT means that the engine is running most efficient. Its a good tool to know before and after performance. Driving down the highway turning about 2250, I am around 750 degrees which is a lot lower than it used to be!

Another thing that I like about these OEM LDT pistons, the truck actually starts within seconds after I hit the start button. Kind of cool if you ask me. I don't need to crank it for a couple minutes to get it to start. haha! I couldn't be happier with them.

 

[mark salanco]

The engine starts almost instantly when cold. Before I turned the fuel up, the EGT would max at about 950-1000, max boost was about 8 psi. Any boost above 8 psi, and the EGT will climb up past 1100.
I emailed Hercules engines, looking for specs on the cam. I want to check the cam for wear.

 

[Wildchild467]

I found this a while ago and it was listed in the TM-9-2815-204-35. It is talking about the LDS 427-2. I do not know if the cams were different with the LDS-427 and the LDT-465.

Here it is anyway for the LDS-427:

 

[mark salanco]

Was also wanting the cam lift .

 

[mark salanco]

I retorqued my heads today, I was surprised at how much they took. I'm guessing I gained a 1/4 turn. The offset wrench I used for the nuts next to the injectors, required me to remove the injectors. I discovered that the 5 one hole LDS injectors looked good, the new 2 hole LDT injector was wet with fuel. I pop tested it, and it failed. I have a new LDS injector soaking in carb cleaner. Also put a new water separator filter and primary filter on. I found a lot of junk in them from that nasty waste oil . Now I have 5 psi at after the primary filter.

 

[o1951]

Glad you caught that. Leaking injectors can dilute engine oil and cause problems.

 

[Tracer]

Getting ready to re torque my heads next week. I was able to find a Snap-on M 4276A wrench to torque the nuts under the injectors. I have about 7000 mi. on my engine since rebuild, so I'm interested so see how much movement I get when I re torque.

 

[mark salanco]

I'm sure some of the dirty fuel probably got to that injector. The system is clean now, so all should be good.

 

[mark salanco]

You will be surprised.

 

[74M35A2]

How does it start when it is cold? Mine was a bear to start when it was cold (60 degrees F) when I had those new style LDS pistons. Right now with my OEM LDT pistons, my boost can barely hit 17psi and the EGTs never get about 1000 empty. I tried and had a little hill and it just didn't get above 1000 and max RPM of 2300. Before when i had the 15psi gauge i could peg that in a hurry as well with those "new style LDS Pistons" but the EGTs would be really high (1200ish).Here is a test... how are your EGTs when you are just driving down the highway? I noticed that mine are a lot lower now than what they used to be. Lower EGT means that the engine is running most efficient. Its a good tool to know before and after performance. Driving down the highway turning about 2250, I am around 750 degrees which is a lot lower than it used to be!Another thing that I like about these OEM LDT pistons, the truck actually starts within seconds after I hit the start button. Kind of cool if you ask me. I don't need to crank it for a couple minutes to get it to start. haha! I couldn't be happier with them.

Your EGT's were high because you had low compression and were burning fuel in the exhaust manifold from some cylinders.

 

[Kora]

Short sighted crooks?
Yes, Now I know.

 

[mark salanco]

So here is an update on my engine rebuild. Just to refresh people on the parts I used.
I used the latest LDS piston sleeve kit, with rings and double piston oilers. Also used a rebuilt LDS injector pump, LDS single hole injectors and LDS intake rockers. The pistons are 20:1 compression.
I used the John Deere break in oil. I have about 350 miles on the engine now, it's running great. The engine starts soon as I hit the start button. I have the fuel turned up to provide 15 psi maximum boost. I also added a water/methanol injection system to the engine. Without the water injection, my EGT would easily go to 1300, climbing in a decent grade. With the water injection it won't go over 1165.
I drove the truck from SC to NC yesterday, I pulled some steep grades that were several miles long. I kept the engine wide open the entire uphill, the boost never went below 15 psi and the EGT maxed out at 1165, I had to let off the throttle one time to let a car by, so I could pass another truck. My RPMs dropped to 2000. I was pleased with how well it pulled that grade, I never left 5th gear.
The engine hasn't used any oil yet, and the coolant has not gone down. I have no issues with water in the oil.
So far, I'm pleased with how the engine runs, it seems to get stronger with more miles.
I'll post a couple short videos and one photo.

 

[mark salanco]

https://vimeo.com/169027388

 

[mark salanco]

https://vimeo.com/169027474

 

[o1951]

Lookin Good!

 

[ShawnIfert]

That is the same blow by as my engine same sound as well. The 5 ton Rockers make bit more noise than the 2 1/2 Rockers.

 

[mark salanco]

It's running great, it seems to get better with more miles. I tray and push it hard when I drive it.

 

[ShawnIfert]

So here is an update on my engine rebuild. Just to refresh people on the parts I used.
I used the latest LDS piston sleeve kit, with rings and double piston oilers. Also used a rebuilt LDS injector pump, LDS single hole injectors and LDS intake rockers. The pistons are 20:1 compression.
I used the John Deere break in oil. I have about 350 miles on the engine now, it's running great. The engine starts soon as I hit the start button. I have the fuel turned up to provide 15 psi maximum boost. I also added a water/methanol injection system to the engine. Without the water injection, my EGT would easily go to 1300, climbing in a decent grade. With the water injection it won't go over 1165.
I drove the truck from SC to NC yesterday, I pulled some steep grades that were several miles long. I kept the engine wide open the entire uphill, the boost never went below 15 psi and the EGT maxed out at 1165, I had to let off the throttle one time to let a car by, so I could pass another truck. My RPMs dropped to 2000. I was pleased with how well it pulled that grade, I never left 5th gear.
The engine hasn't used any oil yet, and the coolant has not gone down. I have no issues with water in the oil.
So far, I'm pleased with how the engine runs, it seems to get stronger with more miles.
I'll post a couple short videos and one photo.

I don't have water injection on mine. I am seeing the 1300 EGT up hill as well. The numbers look very good with your water injection. Have you put Methanol in the mix yet?