Are rings rings?

[AltitudeDiesel]

Hey everybody, being the poor college student that I am I had to let my membership expire a year or so ago but I finally came up with the money to get it back. Thank God for scholarships. :) Anyway, I had some work done by an engine builder in Spokane a few years back and when he tracking down parts for me he said I needed to be very very careful what rings I use in my engine. This question pertains to my DX block 5.7 diesel that I'm working on right now but I'm sure it would be the same for my 6.2, and all diesel engines. He told me that I need to be careful when it comes to oil control rings because some rings cannot stand up to the environment produced in diesel engines and will cause the engine to start burning excessive amounts of oil prematurely. I noticed when I built my first 5.7 that the engine I tore down had a different style oil ring than the one I built, I was unaware of the issue at the time and didn't think anything of it. When I built my most recent 5.7 I was in contact with this guy who had done the work for Dieselfume and I had him track down some of the "special" rings for it but they were amazingly expensive ($400+) for just the oil rings. The rest of the rings were replaced with Total Seal to match the other work done to the engine (studs everywhere, custom cam, headers, retuned injection, etc).

My real question is how much of this is true and how much of it is BS. The other part of this question pertains to how would I go about finding a set of these "special" rings if I had to now since I have lost contact with the person who found the last set. I would like to do some work to my 5.7 such as O-ring and other things to set it up for a twin turbo setup (7-10 psi intercooled only). I'm worried that doing these processes I might damage the rings and in that case if this horror story is true with rings I'd be in a pickle. I figured the wonderful assortment of people here would have some idea as to the truth of this and if there are any alternatives in the 4.057 bore arena.

Thanks in advance,
Tony

[john8662]

Welcome back...

You're about as insane as the rest of us playin with these ol diesels!

Don't know anything about a 5.7 other than they were made.

But, as per rings, I do know something..

In my recent 6.2 rebuild I ordered a set of Hastings rings. I got enough rings for all 8 pistons and there were three rings per piston (well, there were more).

The Hastings rings were close to the OEM rings in most respects except for the oil control ring. The Hastings ring packs included a three-piece oil control ring design:

-First one thin ring (rail)
-then the "expander" ring that looks like a zig zag bent wire
-Finally one thin ring (identical rail to the top ring)

The OEM rings I had on the original pistons were of a Two-piece oil control ring. Where a spring expander was behind a rather large ring that had two "scrapers/wipers" on it.

According to some of the manuals, the two-piece oil control ring is the best ring for oil control in the long run. Some say that the three-piece oil control rings are the best because they're a "tried and true" design. The three piece oil control ring design is what I mainly see more in gas engine applications.

Needless to say I purchased a set of Mahle rings, that had the two piece oil control rings in them.

More important than the rings you're using (use good quality stuff is a no-brainer) is to check the end-gap on the rings when installed into the cylinder bores. Too little end gap, and you'll wear the walls too quickly, too much gap and you get blow-by and a loss of compression.

Hope this helps!

[AltitudeDiesel]

John,

Thanks for the quick reply. You hit the nail right on the head with what I was talking about. The guy who was telling me all this information on the rings said the same thing regarding to the two piece design vs the three piece design. I installed a three piece set in my first 5.7 project and the shortblock is still in storage at my home with less than 10K (valvetrain failure so I went with a new DX block) on it so I have no idea what the results would have been as far as oil control.

He said that the three piece design was far cheaper to produce and since most people with a 5.7 didn't care anyway it's hard to find the two piece rings unless you find them from someplace like Springfield Reman who had a bunch on their shelves when the 5.7 was scrapped but even then good luck. I don't know what the options are as far as 5.7 rings go, I know the 4.057 bore is rare as far as any diesels go so I don't know what I have for options other than to run three piece rings if I have to pull the pistons. At this point I plan to O-ring with the block turned upside down so nothing falls into the bores and hope that is good enough for the girls I go with. I'd really like to drop the compression a point or two so I could feel safe about something with so few head bolts and so much compression getting boost.

Thanks again for the reply,
Tony

[john8662]

I totally second your thought about lowering the compression.

I don't have the numbers off hand, but aren't they either 22:1 or 21:1 compression ratio?

That was a high compression ratio, and for a turbo engine, things get a little shakey. I'd top a set of pistons to lower the compression ratio in the engine. Granted ~10 psi boost ain't too much (compared to newer engines), but it's a whole world of difference performance wise, and stress wise for the engine.

I'm not sure where you're going to find a set of rings. I've run across places on the net that manufacture rings, calling them should net you some results.

o-ringing the block is taking material out of the deck to put a copper washer in right? Either way, if machining is involved, I'd strip the block back down to keep things out of the engine.

This should prove interesting when you get the turbo setup. I've got a guy I work with that had a 5.7 diesel, he wants to do the same thing (turbo), I recomended he drop the C/R to do it also.

[AltitudeDiesel]

Seeing as how the 5.7 is a very short stroke engine it can withstand lots and lots of revs (theoretically). The guy who did some of the work on this one for me had one built in a Monte Carlo that he'd seen turned to 6K before, I'd not want to be around for it but I guess it was unreal. He had his 5.7 with a turbo and it made insane amounts of power. Prior to the current 5.7 he was running, he had built one that eventually came apart, cracked a piston skirt at the wrist pin, and he was pushing 20 psi, N2O and propane into that engine. He had it dyno'd with over 600HP @ 5500. I know why it broke too.

I'm not looking for anything that extreme, I want an engine that is going to run a few hundred thousand and I think I've taken care of most of the problems as far as reliablity went with the 5.7 (roller rockers, studs, etc). As it always happens though, fast is never fast enough, faster is always better, etc. I have the current 5.7 in a 79 1/2 ton with 3.08 gears. It had enough balls to shell the torque converter and I hadn't even really got wild with it yet. This summer (thanks to scholarships) I'll have enough money to swap in a BUILT 700R4 and replace the posi 3.08 with 3.42's or 3.73's. Should be interesting. I doubt the turbos will happen this year but I am going to have the engine out to put the tranny in anyway so I figure while it's back out I might as well get it internally sound.

Tony