I'm sorry but I've been through 3 motors on my 6 only one of them was blown. Blown means I can't get to work the next day. If I can get to work the motor is not blown it's just damaged. I've had the last engine consume 1L of oil for very 200km, it wasn't blown it sure was damaged though. Yet I still got to work so it is what it is, car drove fine with little issues otherwise. It was a true Mazda engine, soul of a rotary.

Vince's car with the cracked ringland made ~340whp on the dyno. I'd hardly call that blown.

What would be an example of a safe tune?
-lower boost
-lower timing
-more fuel
-?

Is there more to it than that.







From what I have gathered working on both motors post disassembly they seemed to have suffered heat issues. Of course the exhaust side will be the one that's damaged that's the side with more heat. Hence why the oil coolers are on that side. We can argue all the small stuff but in the end the motor forged, stock, Ferrari will wear out. The key here is wear out and not blow up (re blown).

If we can run the motor to the point where the ring lands don't crack and the motor wears out I would consider that acceptable. Anyone who believes otherwise is living in a fantasy dream land.

Now on to the solution:


I am more then open to opening up the ring gaps to see if that makes a difference.

There are other solutions as well.

As @Tomas; posted you can add race fuel which will decrease combustion temps and provide knock resistance so you are walking around the issue.

Noob here but I've never seen a thread or a post here about using the ignition per cylinder comp table in ATR. Since there are four cyl but only one knock sensor i don't know how you would isolate which cyl is knocking but maybe running x% less timing in cyl 3 on a consistent basis would curb some of the failure in that lean running failure prone cyl #3 .

If we are not able to address the situation from a general, high-level perspective that everyone can use, based on the forum wide discussions on this thread, then, from my personal perspective, we will have to start looking into the effects of tuning individual cylinders.

I just added quite a bit to my last post. If we can run an 11:1AFR and make the same power we did at 12:1, IMO, there is no reason to even bother running 12:1. It just puts you closer to the edge of detonation, for no good reason.

@David@COBB; is there anyway you can allow us to log the calculated Cat Temp. that the aeroforce and dashhawk can read? We know the PID is there, but there is no way to log it. I know it is only a calculated value, but that still gives us a better idea of EGTs than nothing at all.

On my current tune, a 2nd-4th gear pull left the Cat Temp B1S1 PID at a little over 1400°.

At the end of the day, we are asking our cars to do things they were never designed to do. Things will get damaged/broken/worn/whatever. Let's not get stuck in the weeds nit picking on shit that doesn't get us where want to go. Moar fast.

I've played with fueling on the dyno, and so has Dustin. These engines just don't seem to care and make the same power once you rework timing a bit. I didn't believe it until I did it lol.

Since you actually tested this yourself, I'm curious, what do you target for your AFRs?

I was thinking about some possibilities that might be exacerbating the wall wetting if that is in fact what is going on.

I know that many of the cars that I've worked on, and in my own car, the afr's get silly rich when injecting meth and closing the throttle plate.

Do you guys think that could be a part of, or contribute to the issue?

11.5 is my starting point, and I will go richer from there depending on what is needed and what the intended use is.

Anyway, @Lex needs to get back in here and talk about the issues at hand, rather than succumbing to influences that detract us from building fast cars and actually driving them.

The car does all kinds of stuff when it's hot...including dumping fuel. Prior to going BT, I suffered from the smoking turbo after my first track day...it was sitting there just idling when it started smoking. I completely wrote off the situation as a lot of ppl were experiencing this. We all went head first into understanding fuel dilution, based on the fuel washing down the cyl walls. Everyone got a bnoon bolt...we upped idle...got occ's...etc.

Once I got an occ installed, I noticed that fuel dilution was a really serious issue for me. My occ smelled like gas, the engine oil smelled strongly of gas...furthermore, I'd typically have more liquid [gas + oil] when I checked oil level near a change than immediately after change. So unlike most guys who began losing oil due to low compression, I was actually getting mad wash down. Did the issue start then? idk...could be...

In short: Yes, I think it may be a contributing factor.

How dare you accuse my Rob of instigating you Putz.
The car dumps fuel when hot? I think you need to go back to doing what you do best.


http://youtu.be/ie8yn2J08Qc

I think you and Rob know I wasn't referring to him. And since I think you're trying to be funny to lighten up the mood, I thanked you post.

When the car is hot, and when it knocks, it richens AFR's...it doesn't matter whether you're knocking 2 - 3 counts or maxed 5.9...you car will richen up. But I think you know that already...

So, what about tightening up the piston to wall clearances? This would create a better ring seal correct? I suppose we will just end up back where we started though, because the piston may expand too much and actually seize in the bore. It's almost like anything we try is just going to create a new problem.


Edit: I have a better idea... Let's scrap the DISI and swap in LS1s. :D

Knock is not the same as hot.
And it will only dump fuel when knocking if the table says it should irrespective of temperature. Which I am sure you know.

Sure...and I'm sure you and I agree it's better that it dumps fuel when it's hot and knocking, rather than lean out those "knocking" tables too just to be hardcore?

Tomas...we're car guys who go to the track and we want to help other enjoy their cars. I respect you for that. and that's all that matters...

I have 196569kms stock motor on what @BlueStreak; and @flobio; say is an "aggressive"
tune. I'm almost never NOT WOT. I see coolant temps in the 21X-22X regions even in the winter, and I did a compression test yesterday. 180+/-2 on all 4.
I don't spray meth.

I did? :s


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Yes. At copa cabana.

If I agree to be the closest to retarded on the IQ scale, can we attack this ring land issue?

I hereby declare I am closest to retarded and really have very little business adding my 2 cents in an engineering type thread. There!


Now... can we include everyone?

I will not sign off on that statement.

I might be able to one up you, Rob, and claim full-retard on this. Until last week I had no idea ring lands even existed. I just saw a piston.

Rob...I like talking cars with you. :kiss:

and I used a homosexual emoticon...so can I fit in now?

can we haz car talk prease? is that better english for you motherfuckers?

:crucified:

TBH. I don't recall saying that but at the same time, I do recall thinking that at one point so I won't debate that.

At the same time, I managed to make 400/400 on pump gas (with winter win) so who knows if mine was aggressive. The car hates that tune now in this warmer weather.

I think we're deviating here tho.

Fair enough.
I don't think anyone will ever see 200kms on a built motor before it's "worn out", but mine has neither blow, worn out, or cracked a ring land.
I think, so far anyway, the port meth is a common denominator.
It may not be a root cause, but it has a theme so far. @phate; did the car you showed pics of run port meth?

We need to get more data but I doubt only cars with wmi broke ringlands.

About running richer when hot, the ecu richens the mixture when bats exceed 130.

Cooling via fuel is very effective in this motor and other DI applications.

Aside from the banter we really need more data. When I looked into broken rods we had many data points for analysis. 5 failures is not enough to draw conclusions other than generic ones and we can't even see the data that is trapped in this thread. We should have a separate data and discussion thread.

I know you run WMI Lex and was wondering if you see that same phenomenon of going extremely rich between shifts?

I probably am giving an impression I am opposed to WMI, but I have a kit on my car and still plan on running it.

Agreed. I figured this thread would be like the other database threads. It then snowballed into good discussion and other stuff.

Start up a thread, Lex. Maybe a mod can move the good points over and this one can be distilled into strictly a database /w photos and supporting info.

There's now no doubt to me you're Canadian because you referred to what I call a miserable Friday in March (36 with flurries all day) as "warmer weather".

Fuck you, Dave. lol I look forward to finally driving my car in August when its warm enough to take it out of my garage.

Haha. Didn't even realize but its true. It is warmer out but lots of days are still below freezing.

Let's look at it another way.

A stock motor and stock tune is designed to "save" itself at all costs. One could conclude that a stock motor with a stock tune may never have anything wrong with it provided maintenance is done.

When we start modifying things become a whole new ball game.

I want to say this, not even i-Moto has done a road course with a BT car. I know 3 Canadian locals that have. I'm sure their aren't too many people here either with a BT that do time attack. So if the problem may be entirely ours and caused directly by us.

I don't want to hear this person knows that and this person knows this. I'm getting really tired of this shit. I just want to drive my car without having to do three motor swaps like my last car. Its the internet we are all a bunch of lazy assholes with no money trying to make our slow cars fast. Face it if we could afford it we would all have Porsche GT2's or something a little more "fun" where most if not all of the BS little issues are dealt with by a team of professional engineers.

Now I don't know much about tuning, I know how things work mechanically. I know this, heat wrecks stuff. If too much combustion chamber heat is causing the cracked ring lands, too much fuel is washing down the wall causing more friction (heat) to crack the ring lands, or its detonation it is the same issue. Too much heat or heat where it shouldn't be.

Let me say this again, I don't know much about tuning. Have said that, will the difference in tuning strategy make a difference? If my tuner does high boost low timing, or low boost and high timing, richer, leaner does that affect my output and longevity? Is one more prone to detonation, given the fact that they produce the same torque and power?

At the end of the day I'm here to learn. I could care less if this ring land thing gets solved or not. I have my solution, a forged engine sitting at home collecting dust because I KNOW I WILL BREAK the stock motor sooner or later.

Lex you want more data tell me what you need and I will do it. If the motor gets damaged cares I have the other one. We might as well learn something useful in the process.

and now back to my ice cream and porn . . :omfg:

The data is going to be discussed wherever it is. We can't sit down in a meeting room hand hash it out, all we have are threads. If the @BlueStreak; could just try to keep up and update the OP with information as it is presented we can have the data easily accessible.

Staff members can copy the info from the post to the OP ourselves provided bluestreak doesn't care.

No reason for people to get defensive. This is MSF we are interested in the answers, only time people get ridden is if they refuse to look at the evidence presented and don't contribute. If people start taking pot shots they get bounced, let the data do the talking, and we don't have enough data to point at any one thing yet. The best we can do now is come up with ideas for possible causes and look for evidence that supports the cause.

My .02, this is not something that will be avoided like bent rods. torque limiting tunes allow us to make more power while avoiding bent rods but at the end of the day, making power makes heat, and keeping the oil and coolant temperatures under control and richening up AFRs will only do so much. I think that best case we can come up with guidelines that point to a safe zone, but I don't think there is a secret that will allow this limit to be exceeded that doesn't involve changing the hardware in some way (ring gap, piston shape/material etc....) Aggressive use of the ignition BAT vs ECT tables will probably keep you safer, but will cut power in the process.

I'll update OP tomorrow /w current info and links.

Off to bed now. Early start tomorrow.


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Subbing and plan on keeping an eye on my compression from now on.

did you guy's check if the one with ringland failure still have the egr system ?

Because the egr system is for Nox, but by reducing Nox it also reduce combustion temp by adding inert gas in the combustion chamber.

If you remove the egr systeme, you also remove the safety it also provide.

My EGR was deleted.

I was talking to the local guys about this today on Whatsapp. It'd be nice if we can quantify it, and apparently you can, as @Celestspeed3 showed my a graph that *I THINK* shows the relationship of EGR duty cycle and heat...then again, I was also reminded that the EGR is closed during open loop operation anyway.

Which I guess is why I always tell the local guys to drive the car hard and rev it out a bit every once in awhile, even if they are not aggressive drivers...Italian tune up, they call it...

EGR valve is only open during cruise conditions. Not at idle and not at WOT.

@Ziggo; we did not sidestep the rod issue, we just found out that detonation killed rods and found ways to mitigate this. It's not just the "torque limiting" it's the dangerous cylinder pressures that were eliminated. This can be a similar situation. We just need to see an emerging pattern. So far temperatures seem to be a common variable and I am sure that in some cases detonation is also one.

@rfinkle2; I do notice a rich cell between shifts but this is similar for both cars using and not using WMI.

That is a bit of tricky question but I'll take a shot @ it. The short answer is, if you want to increase the reliability of your map, you will probably have to do so @ the expense of power.

e.g. if you increase the boost, you will have to back out some timing, if you decrease boost, you will have less chance of detonating, but can probably add some timing back in (will probably have to do so to maintain the original power level).

If you increase the fuel and run a lower afr, you will cost yourself some power (especially on pump gas) and my opinion is that this car is sensitive to being too rich... and sometimes rich knock can be induced.

So, longevity can probably be increased by a margin that I'm not sure anyone knows, and probably by a power level that you might not be completely satisfied or as competitive with.

I hate cliches but a fitting one in this instance is "pay to play".

I notice a much more pronounced rich condition after throttle close using meth injection, especially if it is after a shift, but the next gear is not engaged quicky (i.e. logging situations).

The point is, we were able to tune around a hardware limitation and continue to increase the ability to make power/go faster. At one point rods were bending at frequently at 300whp. Now cld12pk is running 500whp+ on the stock rods, and there are a bunch of us running around the 400whp level with the rods still in the block, which is what seems to be precipitating this new failure mode. I don't think this is going to be avoided in a similar fashion allowing the power to continue to increase without changing something internally.

Well it sounds like you have a good idea for the root cause. I know I personally can't say I do based on the few pieces of evidence provided.

I don't think only 400+whp cars broke ringlands if we are to believe at least some of the other low compression K04 cases suffered this fate. On top of this not all high hp cars broke ringlands. There is always something that can be done to mitigate failure if we understand that root cause of that failure. Whether it's cooling, capping power output, or gapping rings but it's too early to tell. Let more data come forward.