Ringland failure on piston no2

[nexia201]

My guess is too much boost mate.

Did you not get the fuelling checked?

no jay cos the last time i was on the rolling road he was scared to remove lambda to take reading from there as i have only one bung in the down pipe as he said the ecu might be reading and would damage the engine which afterwards found i could have taken it out as it only make minor adjustment from it

 

[nexia201]

What boost pressure has your ECU actually been mapped for? If it's not been mapped when seeing 11psi manifold pressure then I would say that's likely to be your problem. A piston ring land isn't likely to crack straight away, it will likely take a period like 'abuse for months' of a lean mixture and detonation to fatigue the piston casting and eventually crack it. Turning the boost pressure up wont damage the pistons, it's the shock wave caused from detonation that the pistons can't cope with, in this respect forged pistons won't be much better.

If you can get away with just replacing No.2 piston, then it's all good, but don't be surprised if No.2 cylinder wall is damaged and pistons 1, 3 and 4 are also weakened from the abuse they've had.

Once you've had the engine repaired, just get the ECU mapped according to how you want to run it.

It might be an idea to invest in one, it could save you an engine next time.

x2 i was stupid cos i was saying if its running ok at 11psi its not too lean ! i will invest in one forsure ! have spent too much in this car !

 

[BallıGee]

no jay cos the last time i was on the rolling road he was scared to remove lambda to take reading from there as i have only one bung in the down pipe as he said the ecu might be reading and would damage the engine which afterwards found i could have taken it out as it only make minor adjustment from it

i take it mr ecu does not have the option of turning off o2 feedback

 

[Texx]

In my view, you can't have too many gauges (unless you have so many you can't see out of the car! ).

My gauges currently consist of coolant temp, oil temp, oil pressure, boost pressure, intake air temp, battery voltage and soon to add to the list exhaust gas temp and most importantly air/fuel ratio. Data logging from an ECU is all well and good, but your not exactly going to be looking at the log whilst boosting off down the road or track, so it's good to be able to glance over and have a pretty good reassurance that everything is ok.

It's better to see a problem developing rather than trying to work out what went wrong after the event.

 

[Texx]

i take it mr ecu does not have the option of turning off o2 feedback

Surely just by unplugging the Lambda sensor the ECU will go open loop and substitute a default O2 value for adjustment?

Although, I can't see how you could have the engine checked for correct AFR without the ECU using the O2 feedback from the Lambda sensor.

 

[Jay]

no jay cos the last time i was on the rolling road he was scared to remove lambda to take reading from there as i have only one bung in the down pipe as he said the ecu might be reading and would damage the engine which afterwards found i could have taken it out as it only make minor adjustment from it

WTF?

He can take a reading from the tailpipe and leave the stock probe in place.

So basically it's been running on a wing and a prayer since installation. I'd reckon she could have been lean all along (As Terry suggests) and the extra boost/heat/stress are simply the straws that broke the camel's back.

 

[HYBRID]

Hey ivan

sorry i didnt answer my phone last friday, but i was at splash and fun all day lol.. it amy's bday so took her out for a whole day in the sun

as terry & jay have very well said, when yohann tuned it for 7psi, (since the mr.turbo does not calculate for +/- over what its been set) it probably ran lean, hence the ringland failure.. when u last changed the rings/pistons did u change no.2 as well? if yes then u have ur answer buddy, ie it was running very high egt due to the lean mixture which has resulted in ringland/piston failure..

if i was you, i would forge, considering all the money you have spent so far on this engine, get a set of pistons/scat rods, get the block knotched, check the tollerances both head & block (jekk hemm bzonn skimja it tnejn li huma) get new head bolts, crank bolts & flywheel bolts.. get everything balanced & re assemble.. its true that you are only running a ct9 so there is no real need of forging, but you could port n polish the head whilst ur at it to get the most of your setup..

if ur a bit on the broke side (bhalli insomma) get a full set of new pistons & rings from toyota, get a set of fresh rods as well, coz ur oem pistons are press fitted so not worth taking them out.. also change the bearings just to be safe, so that u have a fresh as possible engine.. run it in & then take it to yohann to be mapped.

unless ur engine has alot of miles (or running alot of gapping due to quite a bit of boost)it wont smoke through the breather.. so that would be the 1st sign that ur rings are failing..

besides as sheldon said this bloody heat isnt doing our engines any good.

if u need anything just gimme a ring buddy
kon

 

[Sheldon]

think forging is a bit out of the question at the moment eh iv? hafna overtime filkas haha!

id say OEM + remap + AEM wideband !

major heat is one thing engines dont like! especialy forced induction once! so this summer is doing no good! im going to remove the thermostat as you told me and put in one in the winter just in case!

you might also want to heatwrap that manifold ivan... so you reduce some temps in that small engine bay!!!

 

[nexia201]

no prob kon tought you was unable to answer or you would as usual

I think forging is out of question at the moment as i just spent 500 euro on a gearbox and if i did forge it i woulldnt have money left for the rr so im going to get a new piston + rings + headgasket + headbolts + bearings + timingbelt and after its done take it to johann and map it at 14psi

Jay yeah i was telling the guy to put the fucken probe in the down pipe but he insisted that the readings would be far out so wasnt worth it then i gave up

yes sheldon im bloody working overtime for the bitch at the moment and she is taking all my money this is her last chance if something else pop up i will exchange her with a bike (unless it will manage low 13's with the ct9 after the set up )