how my small issue turned to big one

[BlueStreak]

Originally Posted by Lex How many conclusive ringland failures have we had leading to these symptoms? I know of 2 (Dano, BlueStreak) yet I know of lots of cars with low compression numbers. Who else can chime in with the failure when they pulled the motor apart with low compression? @BlueStreak; did you guys take that motor apart yet that had low compression numbers?

Yessir. Confirmed ringland failure on the most recent build.

I believe phate can chime in with more counts of ringland failure.

EDIT: We also have a pu that was driven hard at many time attack events last year. Cyl 4 is down on compression with 20% leakdown. The motor will be coming apart soon for a forged build. Chances are, it's another cracked ringland case.

Sent from my iPhone using Tapatalk

[Lex]

Originally Posted by BlueStreak Yessir. Confirmed ringland failure on the most recent build. I believe phate can chime in with more counts of ringland failure. Sent from my iPhone using Tapatalk

Do you have pics and a story behind the motor and circumstances in which it failed?

[phate]

Tore down one last year and I believe all ring lands were cracked (the 3 remaining, anyway). It was evident the engine had sustained fairly heavy detonation for quite a while, which was the likeliest culprit.

[BlueStreak]

Originally Posted by Lex Do you have pics and a story behind the motor and circumstances in which it failed?

I don't have pics unfortunately. The failure was confirmed by the engine builder over email and I left it at that. They may have taken though and I can find out.

This motor has seen a few years of K04 autocross and time attack and then one season of time attack on big turbo.

Didn't pinpoint the time of failure on this one.

The failure in the pu, on the other hand, was identified at the end of last year's time attack season.


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[Lex]

Originally Posted by BlueStreak I don't have pics unfortunately. The failure was confirmed by the engine builder over email and I left it at that. They may have taken though and I can find out. This motor has seen a few years of K04 autocross and time attack and then one season of time attack on big turbo. Didn't pinpoint the time of failure on this one. The failure in the pu, on the other hand, was identified at the end of last year's time attack season. Sent from my iPhone using Tapatalk

Are these cars seeing high oil/coolant temps during time attack Detonation? Are they using any sort of cooling such as WMI, oil cooler, radiator, etc?

[BlueStreak]

Originally Posted by Lex Are these cars seeing high oil/coolant temps during time attack Detonation? Are they using any sort of cooling such as WMI, oil cooler, radiator, etc?

The pu has an oil temp gauge and reaches 260*F within 2 laps on the track. Don't know about deto.

When mine cracked, I had no counts of KR (had it logging the whole time) during time attack and was spraying meth. I do recall coolant temps in the 230*F. No oil temp gauge at the time.

[mrQQ]

ok, so I'll have the motor taken apart eventually, just to see how that looks, but for now..

which are the parts that definitely need replacement each time you rebuild?

i know this is basic question, but I have no knowledge whatsoever, and I doubt the shop will have any with MZR either, so I might aswell figure it out myself..

if noone is replacing sleeves, then what are they doing?

[mrQQ]

going through @Dano thread.. tis long :O

[BlueStreak]

Originally Posted by mrQQ ok, so I'll have the motor taken apart eventually, just to see how that looks, but for now.. which are the parts that definitely need replacement each time you rebuild? i know this is basic question, but I have no knowledge whatsoever, and I doubt the shop will have any with MZR either, so I might aswell figure it out myself.. if noone is replacing sleeves, then what are they doing?

I recommend reading engine build threads to see what is required. I have one as well titled "Time To Go Forged". @Dano;'s is more comprehensive w.r.t. parts and part numbers. @silvapain;'s too.

I believe only one person replaced sleeves with iron units. AFAIK, the motor hasn't seen much run time tho. What has been done so far is just a hone for standard sized forged piston (if bores are still ok) or a "20 over" or "40 over" bore piston with appropriate bore and honing.

[Dano]

Looks like ringland failures are becoming a mainstream failure mode now that we are better at TQ management and are saving the rods.

is it time to start swapping in cooler thermostats and or get better fan control? Oil coolers. What is the first least troublesome step?

Don't think this is necessary, yet, for a forged motor but the uber tight OEM ring gaps need some better heat management for sure.


Tappin

[mrQQ]

I might have overheated it once, to think about it. It was some drifting on winter lake, with lots of high rpm.

Not gonna trash the car a lot, its a DD with no track time, so would prefer as little investment as possible.

Reading through the threads, but they are long.

K1+Wiseco is what everyone is doing?

What other parts need absolute replacement? Head, cover, manifold gaskets?

Should I be touching VVT/timing at 40k?

What valve works need to absolutely be done? valve cleaning, valve seats?

@Dano, in your pricing excel, what was the tremendous amount for some kind of lube?

[Dano]

Originally Posted by mrQQ I might have overheated it once, to think about it. It was some drifting on winter lake, with lots of high rpm. Not gonna trash the car a lot, its a DD with no track time, so would prefer as little investment as possible. Reading through the threads, but they are long. K1+Wiseco is what everyone is doing? What other parts need absolute replacement? Head, cover, manifold gaskets? Should I be touching VVT/timing at 40k? What valve works need to absolutely be done? valve cleaning, valve seats? @Dano, in your pricing excel, what was the tremendous amount for some kind of lube?

just guessing but it was probably all the lubricants/additives for the 4 oil changes that were planned/occurred in the 1st 1500 miles.

a lot of good it did lol

[sidekick]

Originally Posted by Dano Looks like ringland failures are becoming a mainstream failure mode now that we are better at TQ management and are saving the rods. is it time to start swapping in cooler thermostats and or get better fan control? Oil coolers. What is the first least troublesome step? Don't think this is necessary, yet, for a forged motor but the uber tight OEM ring gaps need some better heat management for sure. Tappin

Have you seen @superskatexes; fan control mod? I don't know how much it actually dropped temps, but you could use a thermostat that opens sooner than the 190° he used.

EDIT: Well, I fucked up his name, but you know what I meant.

[Dano]

Originally Posted by sidekick Have you seen @superskatexes; fan control mod? I don't know how much it actually dropped temps, but you could use a thermostat that opens sooner than the 190° he used. EDIT: Well, I fucked up his name, but you know what I meant.

I have heard about it but not researched it in detail...yet. is our OEM tstat 200*?

hold that answer until I get a thread up regarding heat management in a day or two. Don't want to derail OPs thread any more

[taf0422]

Thought I would add in my current failure. Compression in cyl 4 was half of what the other cylinders were. 180,175,180,90. Did a wet test and shot the compression up to 150. Car has exactly 95k miles. Most of its life at or around 400tq.

The motor will be coming apart this weekend by Pablo so I will have more info after that.

[mrQQ]

add to above questions:

do i need all gasket overhaul kit (its expensive..)

[Dano]

MZR DISI Heat Management

[BlueStreak]

Originally Posted by mrQQ add to above questions: do i need all gasket overhaul kit (its expensive..)

Gasket kit is highly recommended.

[mrQQ]

ok.. so it might take 3-4 months till i get parts in place.

on idiot scale of 1 to 10, how unwise it is to mildy drive the car around, to and back from work at the time?

[TiGraySpeed6]

Idiot scale is easy- just check price & availability of a new short block from Mazda, compare against your credit card available balance.

Temper by the general rule that if you have to ask, it's probably better to park it.

[mrQQ]

got it

[Dano]

Originally Posted by TiGraySpeed6 Idiot scale is easy- just check price & availability of a new short block from Mazda, compare against your credit card available balance. Temper by the general rule that if you have to ask, it's probably better to park it.

haha

FWIW I probably put 2-3K miles on my motor with the broken ringland, and probably 10-15 WOT pulls with VD charts to prove I was not making power...lol This before I discovered the issue.

It is a gamble either way but def not as bad as a bent rod. BTW have you measured rod height to rule that out as a possible cause for your lower compression?

[mrQQ]

Yea, they're all equal. Bent rod shouldn't cause leak in leak-down test either, correct?

2k miles puts me at.. 266 days worth of trips to work LOL

[atvfreek]

Honestly there is probably more people than we know of that have broken ringlands and don't even know it. Long block isn't that much more from Mazda. I would even consider that route. Then you get new chain, vvt etc. Then part out what you can from your old motor to get back some of the money

Sent from your couch

[Dano]

Sooooo true. Now that we are past throwing rods the next weak link is rearing its ugly head and we are right there with the scoobie guys. Lol.


Tappin

[sidekick]

Originally Posted by Dano Sooooo true. Now that we are past throwing rods the next weak link is rearing its ugly head and we are right there with the scoobie guys. Lol. Tappin

Advancing the community one fail at a time

[TiGraySpeed6]

At least we have semi-respectable transmissions

[MajesticBlueNTO]

Originally Posted by BlueStreak I don't have pics unfortunately. The failure was confirmed by the engine builder over email and I left it at that. They may have taken though and I can find out. This motor has seen a few years of K04 autocross and time attack and then one season of time attack on big turbo. Didn't pinpoint the time of failure on this one. The failure in the pu, on the other hand, was identified at the end of last year's time attack season. Sent from my iPhone using Tapatalk

since the motor became my forged motor, we asked the engine builder to check the ring end gap and the ringlands on cylinder 3..here's a pic we grabbed



you can barely notice the cracks in the ringland if you weren't looking for it

[mrQQ]

can someone with knowledge describe the pic?

[mrQQ]

reading through Dano's thread, I get the same with my car:

The problem is high KR under very light loads, say .45 load right at the point of acceleration and deceleration. We've all heard the CDFP rattle on throttle lift and this occurs right at the same time/load but if you just barely hold the throttle steady around 3K RPMs, slightly accelerating the KR will remain constant and an audible rattle is heard. I sounds very similar to a CDFP rattle but perhaps just a tad louder. Now this may have been the case all along but I don't think so. Log attached.

edit: except I can't hear anything

[BlueStreak]

Originally Posted by mrQQ can someone with knowledge describe the pic?

Here's a more obvious portrayal of a cracked ringland. The same issue exists with the photo provided by @MajesticBlueNTO; except the ringland is still holding onto the rest of the piston.

See the chunk missing out of the piston below the top ring? That's the ringland.


Here it is in my hand.


Makes sense now?

[phate]

You guys want to start a thread to document ring land failures? I finally uploaded all of the pictures from a tear down last year, and the pistons were pretty rough.

[BlueStreak]

^^^ If it adds value to the community, sure.

[phate]

It looks to be the next big failure mode

If we don't have a thread by this evening, I can make one. Linking all those pics from my phone is no fun.

[BlueStreak]

Originally Posted by phate It looks to be the next big failure mode If we don't have a thread by this evening, I can make one. Linking all those pics from my phone is no fun.

Ok. I'll start one. Give me a few.

[Dano]

good idea. I haz pictuars as well.

[taf0422]

I will have some pictures as well this weekend hopefully as mine will probably be a ring land issue

If thread is posted can it be linked in here as well?

[Lex]

Originally Posted by MajesticBlueNTO since the motor became my forged motor, we asked the engine builder to check the ring end gap and the ringlands on cylinder 3..here's a pic we grabbed you can barely notice the cracks in the ringland if you weren't looking for it

Is this exactly how the piston came out of the block with the top ring oriented like that or was it moved? Also under what circumstances did this blow?

Originally Posted by taf0422 I will have some pictures as well this weekend hopefully as mine will probably be a ring land issue If thread is posted can it be linked in here as well?

Don't rotate the rings when you pull it out and get pictures exactly as the pistons come out of the block if you can as these will show where the ring gaps are.

The next step is to measure the rings gaps.

[taf0422]

Originally Posted by Lex Don't rotate the rings when you pull it out and get pictures exactly as the pistons come out of the block if you can as these will show where the ring gaps are. The next step is to measure the rings gaps.

Pablo is doing the motor this weekend. I will see what I can do with the pictures. I have a brand new built bottom end going in that he already completed early this week so we will see how detailed I can get the photos or I will do it when I get the old bottom end back.

[Nitr0EngiE]

My head gasket was bad and It did not leak coolant or oil, it was burning coolant in the engine so small amount you cant see in exhaust or any other signs

i had to keep refilling coolant and i was getting alot of unwanted pressure built up in my coolant tank, i was also losing oil very badly about quart every 2-3 weeks

it almost sounds like u got bent valves to me or ringland

had anyone seen a FORGED piston do this in MS3/6 ?

i have a hard time seeing my wisecos doing this