piston rings

[CJJay]

so I have almost given up on getting the engine fixed so I bought a third engine from DEZ 2 weeks ago and am tring to get it fixed. I understood that it had 4000 miles and blew a piston. welll after taking it apart it had 1 inch of sludge in the bottom and looks like a lot more than 4000 on it. I put new rings in it and now it is really hard to turn over by hand with the head removed. do you think it is due to the lack of oil. If so what is the best way to get oil to all the parts befor starting. tomorrow I am going to lap the valves and try to finish it and get it in the cj. want to put it in a car show this week end.

[RussellL]

On one of the forums, I think it was CJ2A, I saw a thread where a guy described using a grease gun filled with oil and connected to one of the oil gallery plugs.  The oil gauge connection would work.  He used the grease gun to pump oil through the entire oil system before starting it the first time.  Seemed simple enough and a very positive way to prime the bearings before the first start up.  

[Redrockman]

What type of rings did you use, and did you check end gap clearance on the rings before installing them?

Did you reuse the old rod bearings too, or were replacements installed?

A few places to start checking, for if you "oiled" the new rings before installing them and put lube on the bearings then it might be a little stiff yet should turn over A OK.

Good luck, keep us posted

Redrockman

[p3ferris]

Another question, are the rods in backwards.  Sometimes overlooked.  This would cause a bind.  Don't get mad  just trying to help.

[Carls_jeep]

Amen to checking the ring gap clearance and having the oil squirt hole pointed opposite the cam. It's real easy to put the rods in backwards.

What ever you do, STOP, and find out what is going on.

[CJJay]

I would never get made at a good suggestion. YOu were absolutly correct I had the 2 middle pistons in the wrong cylinder. all is fixed on both engines as we speak and I will try putting the original one in on thursday. will updat at thst time. If it works don't look for the thread just listen for my giant cry of relief.

[Gunslinger]

Whew!  Another Bullet Dodged!  Good job team.

[Carls_jeep]

If it works then, PLEASE, come back and tell us. It makes everyone wonder if something works or not. Everyone likes to hear that all is well and the problem is gone.

ALWAYS POST THE RESULTS.

[rocketeer]

One more caution before firing it up, hopefully you did not line up the gaps in the rings. All ring gaps should be staggered around the piston. Otherwise on the intake stroke it can suck oil up the "chute".

Larry

[Carls_jeep]

Larry, while it's a good idea to do that when you assemble the rings on the pistons the rings never stay in the place you put them. In the late 1970's Cummins was suffering an oil consumption problem that happened all of a sudden. Well, they didn't have a clue what went wrong because they had not changed anything in the pistons and rings and it was happening on every engine in their line. They went through a lot of experiments to find out what caused the oil consumption. They assembled engines with the rings staggered and with the rings in line and ran them and when the pulled the pistons they found the rings had migrated around the piston. The rings never stay in one place, they move as the engine is running. One experiment was pinning the ring gaps in a straight line up the piston and that didn't affect the power or oil consumption. They did compression tests and combustion pressure tests and having the ring gaps in a line did not affect the starting, running, power output or oil consumption of the engines.

What they found was that Chevron had changed the oil additive package to Chevron 400 without telling them and that change caused the oil consumption issue. Well, they sued Chevron because they had a contract with Chevron to be their only recommended oil with the additive package agreed to and to discuss any changes they may want to make. That oil consumption issue went on for a few years and it cost Cummins a huge amount for warranty payments. I know all this because I worked at a distributor and was the Warranty Administrator. I also machined pistons for our distributor for one of the Cummins factory experiments.

Cummins no longer recommends Chevron 400, now they recommend Rotella T 15w40 for all their engines.

Even after finding the location of the rings made no difference they still didn't change their repair manuals but we told all the dealers about it and left it up to them. I was also the Training Manager in charge of training the mechanics at the distributor and the dealers so I was in on that as well.

[aboyandhisdog]

Carl, that is really interesting!  If I may ask...what was the change in the additives that would cause oil consumption?  Was the oil no longer protecting against wear?  Was it breaking down and losing viscosity?  Geez...I'm learning stuff today and it's only 9am!

[rocketeer]

I'm not talking just about the gaps of the individual rings but the gaps of the compound oil rings. Be aware there is also a top and a bottom to the rings.



Larry

[Carls_jeep]

I never asked what the change in the additive package was that caused the oil consumption. At one point they sent out a notice that they wanted unopened cases of Chev 400 and sealed barrels sent to the factory. Not long after that they sent out an order to not use Chevron 400 and to start using Rotella T 15w40 as the recommended oil.

Larry, your right, the oil rings parts have to be assembled correctly and they rotate as an assembly if correctly assembled. As you said, it's very important to have the compression rings top side up. It's real easy to install the rings, pistons and rods incorrectly in an engine.

[Dez]

Sorry to hear that CJJay, The oil been pretty clean (not really dark black oil i usually see.) Since i bought it and after I removed the head and saw the 060 pistons I figured it confirmed the PO's story. It ran better then all the engines i had previously also. Let me know if theres anything i can do let me know