What causes of Ringland failures?

Our question of the week this week is what are the common causes of ringland failures in Subaru's?
There are three rings on each piston in a Subaru engine. The first 2 are compression rings, and the third is an oil control ring. The metal pieces of the piston that hold the rings in place are the ringlands, and if they crack or break, then the rings are not properly held in place to do their job. When that happens, there are a number of issues that can come up as a result.
Ringland failure is one of the most common failures in a turbo-charged Subaru engine, so this is something that many enthusiasts are concerned about, so we do get a lot of questions about this topic.
In this video we talk about the common causes of ring-land failure, what you want to look out for, and what can be done to prevent it.
Thanks for watching and Stay Tuned!
Website
www.flatironst...
Connect with us on discord
/ discord
Current specials and open box items
www.flatironst...
Check out our blog for more great articles and info
www.flatironst...
Join the syndicate
/ flatironstuning
Follow us
Instagram: / flatironstuning
Facebook: / flatironstuning

[@petrmiskerik]

As subaru wrx sti 2019 owner, I love your content so much 🙂❤🧰

[@FlatironsTuning]

Thanks very much! Really appreciate that. Stay Tuned!

[@thewayfaringanarchists8157]

Ive had HG failure, oil starvation, and a broken crank due to (what i believe) a warn harmonic damper key way but no ringland issues. i think its all having a clean tune.

[@zachscott4867]

Thank you guys for putting this information out and the detailed explanations. It helps people further understand the what/why. I hope ringlands like quicksilver metallic 😬

[@FlatironsTuning]

Ha! If the paint color has "metallic" in the name, you should be good :-) Thanks for watching and Stay Tuned!

[@paulmarsdensr1095]

Great video Gents. I'm keeping my 2020 STI stock. I just hit the 15k mark. I purchased this great car with low miles. Stay safe guys and subies forever.

[@FlatironsTuning]

Thanks for watching and Stay Tuned!

[@marvinvisser5039]

Why? Just make sure you get proper mods and a good tune and know the weaknesses of the EJ. My EJ255 has done over 140000 miles and is now running 340bhp and 500nm.

[@baelm]

GDT or other cylinder #4 coolant mod to keep your hot cylinder happy and EJ alive

[@oscartavares9797]

Mine are probably gonna blow now that I watched this video lol

[@FlatironsTuning]

We would never do that to you :-) Thanks for watching and Stay Tuned!

[@joeywaters1522]

Got to mention the usefulness of a catch can/AOS as the oil that might pass through the PCV can reduce octane

[@FlatironsTuning]

Thanks for the comment. Yes, that can be a potential cause as well. Thanks for watching and Stay Tuned!

[@Sisu_Posse_Racing]

What is your thought about broken ringlands due to the relatively tight stock spec ring end gap? Pre-ign and lean burn causes higher cylinder temps which butts the rings.

[@FlatironsTuning]

Thanks for the comment, and I'll just add our experience here. We are now on the 4th stock engine in our Pikes Peak car. The first was a completely stock EJ255 making about 375 whp, and it lasted 3,000 race miles and 5 years running up pikes peak. We are now making about 420 whp and running E85 on what is now our 2nd Type RA block, and this will be our 11th run up Pikes Peak in a few weeks. We have yet to have a ringland failure. Thanks for watching and Stay Tuned!

[@PolishAlexx]

My engine builder would agree with you

[@jumpenjackflash4964]

@@FlatironsTuning Hello, I just bought a EJ257 Type RA engine from Subaru and on the spec sheet it indicates that the top ring gap is 0.010 for three pistons and 0.011 for the 4th piston. The second compression rings are 0.014 for 3 and 0.015 for the 4th piston. 0.010 is like 3 sheets of paper thick that gap is nothing. I understand your EJ255 was completely stock pushing 375 whp and lasted 3,000 race miles however what about the longevity of the engine? I don't intend on racing this engine, but I would like to refresh most major components and tune it to bring it up to say 350 reliable horses. Is your company based out of Colorado since your running Pikes Peak? Once I get the engine installed would it be possible for your establishment to tune my engine? What transmission were you running with the 255? Second Question: Do you know of a good tuner in New Mexico that really knows their stuff? Regards Fred NM

[@baelm]

@@jumpenjackflash4964 they really give more gap in cylinder 4? wow

[@vernonharless3083]

You are right.

[@shiloh5199]

I like watching your videos, a lot of good content...keep producing more videos.

[@FlatironsTuning]

Thanks very much. Don't worry, we have a lot more in the works. Thanks for watching and Stay Tuned!

[@DJ_Driven]

Can you guys make a technical video showing your recommended procedures for boost leak testing, as well as a smoker machine to flush out vacuum leaks?

[@FlatironsTuning]

Thanks for your question. We did cover this on one of our early QotW videos. If you haven't seen that, take a look here: kzbin.info/www/bejne/pqXSlH6aa6-DsNE And if you think we should still take a more detailed look at doing a smoke test, let me know. Thanks for watching and Stay Tuned!

[@DJ_Driven]

@@FlatironsTuning I'm thinking the community could benefit from a in-shop technical video on diagnosing a customer or shop vehicle with your recommended equipment test procedures for boost as well as vacuum leaks. You could also make it a recommended pre-inspection diagnosis prior to the dyno testing video. Watch lots of videos of cars struggling on the dyno because of minor issues like vacuum / boost leaks that the customer was unaware of because of not doing a pre-dyno diagnostics.

[@jdm_motive1]

Thanks guy's 😊

[@FlatironsTuning]

Absolutely! Great question. Stay Tuned!

[@suardyjoffry49]

Does installing cylinder 4 cooling mod helps prevent ringland failure?

[@FlatironsTuning]

No, that would not help prevent this. Thanks for watching and Stay Tuned!

[@baelm]

@@FlatironsTuning How would it not?

[@itz-red1792]

When a ringland failure does this mean the engine has to be rebuilt ? On a 2010 Subaru wrx sti Impreza

[@FlatironsTuning]

Thanks for your question. Yes, when the ringland of the piston fails, the only way to correctly fix it is to replace the pistons which requires rebuilding the engine. Thanks for watching and Stay Tuned!

[@Koukiisan]

You guys said with hybrid swaps are the hot spots because of the change in compression to cause pre ignition does this still occur when you swap the pistons to the proper compression to match the heads

[@FlatironsTuning]

Thanks for the question. Fixing the compression is a good start, but you really want the top of the piston to match the combustion chamber. The proper quench area is really important there. Thanks for watching and Stay Tuned!

[@Lucas-nz8em]

I prefer my clearances tight, stock pcv system, octane low, boost high and DAM at minimum of .05

[@tl4581]

strange how EJ207's dont have this issue as much as the EJ257, piston size a variable?

[@AmirPomen]

Not piston size... But the piston design changes that have to be made due to engine spec changes... Since the shortblock cannot grow wider (longer conrod), ej25 vs ej20... Ej25 have longer crankshaft throw for longer stroke (79mm stroke vs 75mm stroke) which equals to +2mm stroke length at tdc and bdc... That +2mm of longer stroke have to go somewhere up... While conrod length ideally to be longer or kept the same, going shorter conrod will have mode bad side effect... Hence the piston wrist pin location need to go up +2mm... And the rings also need to go up closer to piston crown (facing more heat in combustion chamber and more prone to detonation) While the subaru ecu tuning from fctory is being optimized for regular gas or premium, as for power it often best performs on premium gas... But subaru user sometimes will fill up with regular fuel... It will detonates...and eventually ecu will compensate by knock signal feedback from knock sensor... And the response to that ignition iming changes by ecu not often fast enough...opens up vunerability to detonation as the ecu making changes for better power and knock feedback... A good tuner definately will helps alot in this case to optimize the ecu mapping for reliable regular 91 gas...

[@FlatironsTuning]

Thanks for the question. Yes, the piston size if part of it, and so is wrist-pin location. We may dive into this more at some point. Thanks for watching and Stay Tuned!

[@tituslarsson1475]

Want to avoid ringland issues? 2.0L.... The piston pin was moved up 2mm in the pistons for the 2.5L vs the 2.0L version. The crown was then shortened and with the dish shape on the 2.5L turbo pistons there really just not enough material left on the crown to protect the rings from combustion. Compare the to pistons side by side. 2.0L piston takes 23psi all day and the headgaskets hold using stock head bolts as well. Try that with your 2.5L and your quickly going to break something.

[@FlatironsTuning]

Thanks for your comment and thanks for watching. Stay Tuned!

[@baelm]

my 205 sounds like it has piston slap from #4 but i really can't pinpoint it or even hear it under the hood, boggling the hell out of me. sounds like a death rattle from inside the car. it was rebuilt with who knows what parts but has lasted me 20k so far

[@nrw510]

Jon I'm in middle of doing a hybrid swap. I had the heads chambered by a machine shop. Will the issue you identified still be present or is that if you run the thicker head gasket?

[@FlatironsTuning]

Thanks for your question. If you had the heads chamber matched, then they should mate up properly to the pistons, and yes, that would correct this issue. Thanks for watching and Stay Tuned!

[@AmirPomen]

Also factory piston ring gap clearance were too tight that when engine is tuned to have more boost, more fuel, it expands too much to a point it have nowhere to go and get stuck with piston going up and down the cylinder wall at high stress... That also would lead to broken ringland...

[@FlatironsTuning]

Thanks for the comment, and I'll just add our experience here. We are now on the 4th stock engine in our Pikes Peak car. The first was a completely stock EJ255 making about 375 whp, and it lasted 3,000 race miles and 5 years running up pikes peak. We are now making about 420 whp and running E85 on what is now our 2nd Type RA block, and this will be our 11th run up Pikes Peak in a few weeks. We have yet to have a ringland failure. Thanks for watching and Stay Tuned!

[@AmirPomen]

@@FlatironsTuning definately good tuning strategy helps minimize the risk of ringlandd failure.. Keep em coming.. 🍻 cheers

[@brother_maleik]

Kinda weird question but how do you know if you're getting good fuel??

[@RobHTech]

What about the 2022 FA24? Still ring land problems? I'm having trouble finding any specs about the internals of the 2022 FA24 -- like forged/not, type of pistons, rods, crank, forged block/not, etc. Does anyone have any input to help me? Or, maybe point me to a reputable source about this?

[@FlatironsTuning]

Thanks for your question. Yes, the FA24DIT still uses cast pistons. As the car is so new, it is a little early to see what the potential issues may be. There are a few shops that have been getting very good results with the Ascent, so I'd recommend searching for those if you haven't all ready. Thanks for watching and Stay Tuned!

[@evrnire8474]

My question (of the week) is, is the 2.5 EJ more susceptible to ringland failure than the 2.0L? I have a early EJ205 and from what I’ve heard, on these engines, running lean tends to cause bearing failure rather than ringland failure... maybe because of smaller bore?

[@FlatironsTuning]

There are definitely a couple of key differences between the EJ25 and EJ20. Piston size is a part, but so is wrist-pin location. They both play a roll in making the EJ20 a bit less susceptible to ringland failure. Thanks for watching and Stay Tuned!

[@oneninerniner3427]

that's what i was going to say. more octane, higher octane fuel needed, everything else being correct of course.

[@FlatironsTuning]

Thanks for watching, and Stay Tuned!

[@tbas8741]

One of the very common causes is also Poor driving habits or not people Simply forgetting to DOWNSHIFT when passing cars or boosting up hilly roads. Instead of using 3rd gear (5speed) or even 4th on 6 speed, They are cruising at 40mph behind a slow car then pull out and Floor it in top gear. Making full boost at low RPM those pressures inside the cylinder are insanely high (much higher than pressures in 3rd at near redline with fullboost) Heat builds up then LSPI happens and damaged Ringlands. (Low speed pre ignition) Can make brand new cars from other makers blow ringlands in a few hundred km of bad driving. Sit on 40mph @ like 2500rpm and floor it in top gear making fullboost. repeat this a few times and even $200,000 BMW will blow ringlands

[@sohchx]

I'm sorry but I still can't help but blame OTS maps on my situation. Fast forward to now and I've been pro tuned for the past 18 years no issues

[@edenmuhace387]

So basically what I gather from this is, make sure you're vehicle is running properly and stop being cheap at the pump buying that "poor people gas"?

[@FlatironsTuning]

Definitely a solid practice to keep your Subie running well. Thanks for watching and Stay Tuned!

[@pv4083]

Sounds to me like leaving a sti stock is your safest bet

[@marvinvisser5039]

False, mine has done over 140000 miles and is running just fine

[@pv4083]

@@marvinvisser5039 that’s great do you recommend anything in particular so that others can have a similar experience?

[@micko9111]

not really stock still has oil pick up crack and piston failure

[@pv4083]

So basically don’t buy this car?

[@8literbeater]

"Ringland" is no more of a word than "pistonpin" or "rockerarm" or "cylinderwall". They are RING LANDS.

[@salspec3381]

This doesn't seem conclusive to me. Why have so many stock Subaru's suffered ringland failure since 2007?

[@isaacvelasco6498]

The unequal length header setup causes cylinders 2&4 to have excessive heat build up because of how far the EG has to travel to the downpipe. This heat causes predetonation within the cumbustion chamber then the piston hits against the cylinder walls and breaks the ringlands around them. As well as subaru using cast internals is the driving force of components failing and being weak.

[@salspec3381]

@@isaacvelasco6498 Actually unequal length headers reduce scavenging on 2 & 4. This leaves spent gases in the cylinder leaning out the AF mixture. However UEL headers have always been used on EJ's and ringland failure didn't start happening until 2007. So the header argument is inconclusive as well. That said I think EL headers are a great reliability mod because they help to equalize temps across the cylinders.

[@DJ_Driven]

Cylinder 4 is the sacrificial cylinder that takes all the abuse and is normally the first cylinder to fail. Cylinder 4 is actually designed weaker than the other three cylinders. Some people resort to trying the cylinder 4 cooling mod, but who knows how much that truly helps or can contribute to some other unique issue.

[@DJ_Driven]

@@salspec3381 it's in the factory tune cylinder 4 is where the knock sensor is for a reason. Also study the cylinder 4 head port design flow not so good.

[@salspec3381]

Yes cyl #4 does run hotter with the oem manifold (so does #2). It may have been an oversight, but I've seen no evidence it was intentionally engineered to be weaker. Plus ringland failure can occur on any cylinder. Is it more likely on 4? Maybe. Conclusive no. Again this didn't start until '07. The EJ design was not really changed so why did it start. New ECU programming, cost cutting... there are plenty of possible causes, but conclusive? I'm not convinced. Especially when it comes to ECU programming. People were getting stage 1 tunes and still had ringland failure.

[@Grc011]

Why would Subaru build a car so sensitive

[@FlatironsTuning]

Well, I'd say that it isn't as much of an issue if you modify them wisely :-) We have yet to break a ringland in our PPIHC car and it is making 420 whp now. Thanks for watching and Stay Tuned!

[@Grc011]

@@FlatironsTuningoooo ok I see so if your not planning on pushing big numbers or anything this shouldn’t be something concerned about ?

[@FlatironsTuning]

​ @gilbert Cuellar Sort of. I would say that you just have to follow a tested and proven mod path, and make sure that the car has a good tune on it and is running properly. On these cars, things like vacuum leaks, or improperly installed parts can cause a lot of issues. Those mistakes aren't always identified properly, and Subaru's end up getting blamed for being weak or unreliable. Take a look at this video we did a couple of weeks ago if you haven't seen it yet: kzbin.info/www/bejne/mJekfKaChrZ7jpY

[@Grc011]

@@FlatironsTuning thank you for the info helped a lot

[@stringgreens6387]

You didn't say anything about thermal expansion. Metals expand with heat...the longer you stay in boost the more the piston will expand and tighten the ring gap...eventually breaking it. Purpose built race engines are built with more tolerance for a reason...street motors are built with a tight tolerance and cast pistons with less thermal expansion rates for the average start and go mindset..better cold start emissions, less wear and tear on the cylinder walls, but the tolerances aren't there for long durations of boost. Subaru did what they had to do to sell the sti in America. Sadly Americans don't know how to let off the gas and let her cool down some.

[@FlatironsTuning]

Thanks for the comment, and I'll just add our experience here. We are now on the 4th stock engine in our Pikes Peak car. The first was a completely stock EJ255 making about 375 whp, and it lasted 3,000 race miles and 5 years running up pikes peak. We are now making about 420 whp and running E85 on what is now our 2nd Type RA block, and this will be our 11th run up Pikes Peak in a few weeks. We have yet to have a ringland failure. Thanks for watching and Stay Tuned!

[@stringgreens6387]

@@FlatironsTuning Doesn't E85 burn cooler? Doesn't E85 have more oil content in it? How much Boost? Long durations of low boost compared to high boost I'm sure would make a difference in temps everywhere. I feel like your using E85 as a fail safe, but what ever works for ya. Not everyone has access to this magical E85 fuel.

[@FlatironsTuning]

@@stringgreens6387 We only made the switch to E85 in 2020. Before that we ran race gas that was 104 octane. But yes, E85 does help keep in cylinder temps lower, and it is more resistant to detonation. Race gas does run a bit cooler as well, but nowhere near what E85 does (which is why we made the switch).

[@Nostradamus_Order33]

Synthetic oil causes this problem