Piston Rings Worn Out, Time for a Rebuild

[Wildchild467]

I love getting my rod inspected, my prostate, not so much!

That is how I feel with this engine rebuild even before I turned the first wrench. I knew something wouldn't work out right.

I'm just nervous about cranking the engine up that much on the dyno. I'm just nervous it will come apart (since 2600 is a lot of RPM for a older bigger diesel like this). If it blows up, I'm out about $2400 plus the price of a replacement engine. Not sure I would have motivation to keep the hobby going if that happened. Keep your eye in the classifieds if it does.

 

[Wildchild467]

Normally, yes, that or towing a loaded trailer is probably the best you can do. I have a precision chassis dyno used for emission system calibration that we can put his truck on and load to spec rpm and hp, so, lucky him, he can follow the manual, up to the point his feathers are sticking out anyway. It is has 4' diameter steel drum rollers sunk into the floor and can absorb up to 500whp and +200mph. The small twin roll "Mustang" type dynos are fabulously portable and low cost, but they are not EPA certified because they don't closely simulate a flat road via the twin rollers. Doesn't matter in this case, just info.

Still say we should do an emissions test on it since we are running it on a dyno.

We'll have to record it too so we can show people what a multifuel looks like blowing up on the dyno. It would be my luck. Oh well. sorry for being negative Nancy. This project is taking forever and costing lots of money.

 

[Wildchild467]

As someone with no experience with working on engines I learned a lot by reading this thread. So to everyone that has contributed, thank you.
One thing that was talked about frequency but at least to me never thoroughly explained was cylinder glazing. This link is the best explanation of cylinder glazing I could find. https://coxengineering.sharepoint.com/Pages/Boreglazing.aspx

I'M glad. That is why I am trying to put so much energy into documentation. I want the next guy to learn something more about these things and maybe learn from any of the mistakes I might have made... like buying new piston kits when I would have felt better re-ringing my stock pistons.

 

[74M35A2]

You did everything perfect mechanically. I think it was attempting to break in on WMO. Go diesel fuel, we'll load on dyno, and it should be the best running one out there.

 

[Wildchild467]

I found in another thread that somebody did a compression test on their engine. They had some issues with a cylinder not firing, but the highest cylinder pressure they got was 450psi. It's a good thing to note if I am putting this together and want to know what other people are getting for compression. I knew I should be at least getting 400psi since that is the highest number I got before rebuilding it.

 

[74M35A2]

Still say we should do an emissions test on it since we are running it on a dyno.

We'll have to record it too so we can show people what a multifuel looks like blowing up on the dyno. It would be my luck. Oh well. sorry for being negative Nancy. This project is taking forever and costing lots of money.

I get it. I just like picking on you. Run 2800 and I'll sample your exhaust.

 

[Wildchild467]

I might have found more information on piston rings for the new style LDS Pistons. These pictures seem to show only two compression rings which indicates to me that they are the new style. I still have not found anyplace to buy replacement rings for these new style LDS pistons.

View attachment Deuce Piston AssyTM-9-2815-210-34P.pdf

 

[Wildchild467]

I get it. I just like picking on you. Run 2800 and I'll sample your exhaust.

2800 no load, 7 pound pistons, what is the worse that could happen? If it blows we can at least say we followed the manual.

 

[welldigger]

2800 no load, 7 pound pistons, what is the worse that could happen? If it blows we can at least say we followed the manual.

Tractor pull guys have wound these engines to 3500 plus rpm and they stay together. 2800 isn't as wild as you think.

 

[o1951]

You did everything perfect mechanically. I think it was attempting to break in on WMO. Go diesel fuel, we'll load on dyno, and it should be the best running one out there.

Agree!
Also consider Deere break in oil. As I said before, I hate working on engines in vehicle, so I would spend the extra bucks for a name brand, proven break in oil from a major diesel equipment manufacturer.

 

[o1951]

I might have found more information on piston rings for the new style LDS Pistons. These pictures seem to show only two compression rings which indicates to me that they are the new style. I still have not found anyplace to buy replacement rings for these new style LDS pistons.

View attachment 608454

I do not like them! Do not like short skirt. Whenever we changed pistons on engines (gasoline, 5000+ RPM), we had crank rebalanced. I know, 2800 RPM is not that fast, but there still is a change in balance.

 

[o1951]

2800 no load, 7 pound pistons, what is the worse that could happen? If it blows we can at least say we followed the manual.

Don't get so nervous!
If you use new, high quality rod bolts and assemble & torque correctly, highly unlikely anything will happen at 2,800. I would not go much beyond that, tho. If you are concerned, You don't HAVE to hit 2.800. I think 2,600 will give a good break in.

 

[gimpyrobb]

That is how I feel with this engine rebuild even before I turned the first wrench. I knew something wouldn't work out right.

I'm just nervous about cranking the engine up that much on the dyno. I'm just nervous it will come apart (since 2600 is a lot of RPM for a older bigger diesel like this). If it blows up, I'm out about $2400 plus the price of a replacement engine. Not sure I would have motivation to keep the hobby going if that happened. Keep your eye in the classifieds if it does.

Hows this, If your motor blows up while dyno testing, I will donate a motor to you. Publicly stated, plenty of witnesses.

2800 no load, 7 pound pistons, what is the worse that could happen? If it blows we can at least say we followed the manual.

Some LDS IPs were governed at 2900rpm.

 

[Wildchild467]

Hows this, If your motor blows up while dyno testing, I will donate a motor to you. Publicly stated, plenty of witnesses.


Some LDS IPs were governed at 2900rpm.

You're the best Gimp. Now that you said that, it wont blow up. Its like buying a new snowblower before winter so it wont snow. haha!

I have an LDS pump on my truck now. I can run the engine at 2600, but I don't need to hit 2800 for the test really, only to set max no load speed.

 

[daytonatrbo]

I do not like them! Do not like short skirt. Whenever we changed pistons on engines (gasoline, 5000+ RPM), we had crank rebalanced. I know, 2800 RPM is not that fast, but there still is a change in balance.

This brings up a good point.

What's the difference in weight between the new pistons and old pistons?

 

[gringeltaube]

... 10g.

Read my post #125...

 

[rustystud]

That is how I feel with this engine rebuild even before I turned the first wrench. I knew something wouldn't work out right.

I'm just nervous about cranking the engine up that much on the dyno. I'm just nervous it will come apart (since 2600 is a lot of RPM for a older bigger diesel like this). If it blows up, I'm out about $2400 plus the price of a replacement engine. Not sure I would have motivation to keep the hobby going if that happened. Keep your eye in the classifieds if it does.

Since this is a real Dyno it will be applying a proper load to the engine. This is very important to the engines ability to stay together. If you just revved up the engine to 2800 RPM's with no load then yes it could come apart. Like Tracy (the tractor racer) told me these engines can rev pretty good with just a minimum amount of modification . So I wouldn't worry.

 

[daytonatrbo]

... 10g.

Read my post #125...

Sorry, I've lost track of the first half of this thread.

 

[Wildchild467]

Does anybody have any information on what order the piston rings go on the 4 groove LDT pistons? Here is what I think so far:

-Top ring #1 and second ring down #2: Bevel on the inside of the ring faces up. These two rings appear to be the same.
-Third Ring down: This ring is a little thinner ring than all the others, so I know it goes here. It has a small circle stamped on the top of the ring, so I assume that circle faces to the top of the piston?
-Forth Ring down: This is the oil ring. This ring is not completely smooth on the bottom (like a castle nut to exaggerate it) and I don't know what way is up. I wish I had a picture of it, but I forgot to get one this morning. So if anybody has put these in their engine, let me know... i'm confused on how to orientate the bottom ring.

UPDATE:

The oil control ring castellated face of the ring goes down and the smooth portion points up. So far everything I have found, any dot/circle/stamp that is on the rings should be pointing toward the top of the piston. With these oil rings, I opened a pack of NOS rings and there was an ink stamping on the ring that said, "TOP". The other rings I had did not say this, but this one did... so now we know.

 

[Wildchild467]

We were going to shove all the removed parts such as the pistons, bearing, rings, and gaskets, into a big pile out in the driveway, and throw it on classifieds as a used 465 rebuild kit.

I'm glad I didn't let you do this. It pays to keep some old parts that are still good.