I had interesting conversations with a few fellow engine builders today. Thought my fellow gear-heads @ nasioc might find this noteworthy.

While I have used Plasma-moly top compression rings exclusively in my engines in the past (from 9:1 stockers to 13.5:1 ProShot Foggers), there is always something to be learned from your peers, hence this thread.

Note #1: My apprehension about using Chrome-plated comp rings was based on past experience (read: 1980's technology)...i.e., hard to seat, hard on cylinder walls, not every machinist is skilled at honing for them, etc. The folks I spoke to today (to a man) said that "with proper assembly and honing technique, Chrome-plated rings are not only better suited for high-boost (>15 psi) applications, they will seat almost as fast. Modern-day chrome rings are far superior to those of the past". :eek:

Note #2: Builders also stated that due to most turbo engines being of the fuel injected close-tolerance import tuner type, the "detonation will almost certainly cause the moly coating to flake off the top ring". Not good. Not the first time I've heard this, either.

Note #3: These builders are "using Chrome plated top comp rings in all of their turbo builds, and know many others that do", as well. News to me. :lol:
I've always been a on-the-transbrake-and-spray-the-guts-out-of-it-guy. :D

This conversation was brought about due to my expectations of getting Plasma moly rings as quoted by Magnus Motorsports, calling the manufacturer and cross-referencing part #s, and realizing I had chrome plated top rings. :mad: I wanted to know why the ring manufacturer and the piston manufacturer suggested using this type of ring...now I know. :)

BTW, they all suggested using a 220-280-400 (stepped to finish) cross-hatch on the walls, and suggested roughly 8-12 psi of boost @ 80% rpm max and loaded driving to seat the rings. ;)

Steve

:lol:

Not enough gearheads, I guess.

For those paying attention:

Fit to within .001" of final with Alum Oxide 220 (C30A55), then 3 light strokes with Silicon Carbide 280 (C30J65), then to final hone with 2 light strokes of Silcon Carbide 400 (C30J85). :)

Interesting comments. On the older Chrome rings they also worked better in the harder cast iron blocks. Not sure how our cylinder liners compare to some of the old school hard cast iron blocks. Any one have a broken cylinder block they want to send out to get the hardness of the liner measured ??

I've long been a proponent of listen to the ring manufactures -- they usually know their product a lot better that we do and do tons of testing to sort this sort of thing out.

I know if properly preped and broken in, the chrome rings would outlive just about anything else. The moly face rings are mostly (as I understand it) a quick breakin, forgiving ring for the manufacturer, that allows them to not have to deal with complex honing procedures during production.

I know the chrome rings "DEMANDED" a high load break in cycle or they simply would not seat, so the 8-12 psi boost break in cycle makes perfect sense to me.

Larry

My fabricator thought it was absurd that chrome rings were still being used due to the break in issues. Maybe they (chrome rings) have changed since he was building race engine for the Petite Lemans cars. He said their race engines never had to be broken in. There wasn't really a procedure for this. They ran them and that was that!

Now on the cyl hone, I'm with you on this. After much reading today on engine building, that seems to be in line with what the builders are recommending for cross hatching.

Paradigm shift


Steven Covey, is that you!?!?!? hahahaha

Trust me we're reading you threads.

Thanks for the work!

Trust me we're reading you threads.

Thanks for the work! x2 3 4 5 AND 6

My fabricator thought it was absurd that chrome rings were still being used...

Me too. Until recent conversations. They seem to be the trick for blown / turbo applications.


Maybe they (chrome rings) have changed since he was building race engine for the Petite Lemans cars.


Evidently they have, because the folks I spoke with aren't doing this for fun. ;)


He said their race engines never had to be broken in. There wasn't really a procedure for this. They ran them and that was that!

Except for heat cycling and changing the oil, that's the way I've always approached it.

HTH

S.

Well, do I at least get a prize for participation ;)

Well, do I at least get a prize for participation ;)


Why, thank you. ;) And while I'm at it, thanks to Hotrod, hondaeater69, Redleader, and T3rminal.....none of this would have been possible without you all. :D Thank you. <Curtain> :lol:

great info steve.

when are you gonna build my sorry broke a$$ a motor? :) :D

"paradigm shift" is from Thomas Kuhn. It was a bogus phrase to decribe scientific advancement. He's a philospher and has been basically discredited by nearly everyone, but that darn phrase persists. Alright enough wasted verbage.

I think chromed rings would be great and I think the bits about improved tolerences is very on the mark. CNC machining has changed a lot of things. If the bore is true, the chromed rings should not wear anymore than anything else and it is harder material than steel. They should last forever.

One thing I'd wonder about is brittleness of the rings. We hear about broken lands all the time. But I wonder if the chromed rings would be any more brittle (given the occasional knock event). I'm not a metalugist, so what to I know.

Did the guy you talked with say anything about being able to run with less of a gap to help with blow by?

Thanks for the "modern" update on chrome rings!!

They should last forever.

That's a fact, or at least a very long time.



One thing I'd wonder about is brittleness of the rings. We hear about broken lands all the time. But I wonder if the chromed rings would be any more brittle (given the occasional knock event). I'm not a metalugist, so what to I know.

Not any more brittle than a cast iron ring....see your second comp ring.



Did the guy you talked with say anything about being able to run with less of a gap to help with blow by?

No, and I can't see the reason one would want to decrease the ring gap for differently plated/coated rings; the gap is there to allow for piston expansion. :)

Thanks for the "modern" update on chrome rings!!


Your welcome.....I'll need lots of help with the Hydra. Quid pro quo. :lol:

S.

All I really know is never use chrome on chrome... I dont believe we have chrome liners tho. I have read in a few places that chrome does not hold oil as well as molys which is quite porous... correct me if I am wrong, but isn't that something you really want in a ring? The only people I heard of using chrome rings were for all most total off road use.


The three popular types of top compression ring face coatings, chrome, moly, and cast iron, each has advantages of its own with respect to operating conditions. Moly has a very high resistance to scuff. Chrome has good resistance to scuff but does not exhibit moly's oil retention capabilities. Plain cast iron is a durable wear surface in normal operating conditions and is less costly than the moly or chrome faced ring.
http://www.hastingsmfg.com/Service%20Tips/ring_set_composition_recommendat.htm


If chrome plated rings are this wonderful they are one of the greatest secrets in all of motor building. The the ring manufactures tend to say the same things... chrome is not for high performance motors. Thies motor builders using them what are they using them for? Mt climbing/rally?

If chrome plated rings are this wonderful they are one of the greatest secrets in all of motor building. The the ring manufactures tend to say the same things... chrome is not for high performance motors.

Easy, big fella. Rather than posting something you read off the 'net, call the ring manufacturer (or a reputable forced induction engine assembler, if they'll tell you), tell them you are planning to build a 25-32 psi boxer engine, and see what they recommend. Respect for your search capability, though. ;)


Thies motor builders using them what are they using them for? Mt climbing/rally?

Here 'tis:

Note #3: These builders are "using Chrome plated top comp rings in all of their turbo builds, and know many others that do", as well. News to me.


The info is what it is. Do what you like. :)

tell them you are planning to build a 25-32 psi boxer engine

Well that may be my problem right there... most of the guys I talk; the closest they get to boxers is the kind you wear and its not something totaly random off the net its from Hastings.



Just trying to get a conversation going here...

One thing I'd wonder about is brittleness of the rings.

Dont the ring lands break more then the rings on thies stock motors? I mean isnt it more the pistons design more at fault?

Dont the ring lands break more then the rings on thies stock motors? I mean isnt it more the pistons design more at fault?

Stock pistons - yes! How many broken ring lands have you heard of with (name your brand) forged pistons?

Stock pistons - yes! How many broken ring lands have you heard of with (name your brand) forged pistons?

One last quip on this subject, one last time:

I've found more than one EJ257 with the top ring gap set at .009", and the second @ .011". That will break ring lands in a hurry if enough heat (power) is made. :)

Hopefully you didn't misunderstand what I was saying. I was trying to say that ringlands seem to break on a less than ideal occurence on stock cast pistons. However, regardless of what ring(s) you're using, I have not heard of broken ringlands on forged EJ257 pistons (yet).

Hopefully you didn't misunderstand what I was saying. I was trying to say that ringlands seem to break on a less than ideal occurence on stock cast pistons. However, regardless of what ring(s) you're using, I have not heard of broken ringlands on forged EJ257 pistons (yet).

Actually, what I intended to get across was pointed more at

Dont the ring lands break more then the rings on thies stock motors? I mean isnt it more the pistons design more at fault?


and in addition to what you were saying, rather than being at odds with it.

Sorry for the confusion, Todd. :D

I will say this however: Install a set of rings (regardless of the type), or the P-W clearance too tight, and you can break the ringlands in any piston....forged, titanium, or otherwise. :)

S.

Bump for move to "built engine forum" :)

S.

Olé!!