well these pics says it all, ring land failure
Turbo Mini Forums

well strip the engine down and yes number 2,s ring land shad failed and so has number 4's to.

if you all remeber i had smoking probs from very early on after just 200 miles of running in.
spoke to gav at minispares and sent him some pics and he will see what he can sort out.

i rember so others on here who have used the turbo mega pistons and have had this happen. i still believe its a manufactoring fault.

but we will see what minispares come up with.

always looking for them bigger bunches of bannanas

see if these pics work

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always looking for them bigger bunches of bannanas

Can you put up some pics of the piston crowns?
In the second picture just right of centre at the very top there looks to be some detonation marks to the crown.
Detonation = ring land failure.
Regards
Dave

i had the same problem. never had that with omega pistons though.

The root of the problem!!

Has it taken the bores with it?

What do the tops of the pictons look like?


Alex

AlexF

pistons look spot on and thankfully so do the bores, but there is a slight skuff on number 2 at the top but that will hone out im sure.

always looking for them bigger bunches of bannanas

Sorry to see that again Hogster.
Mine were also Mega pistons, and looked exactly like yours when they failed... If you get anywhere with Minispares keep us posted.

I bought them early 2007..

Terry

website:- http://www.terryhunt.co.uk

Bloody hell mate, al last you find out, and it wasn't work workmanship after all, so we have to be thankful of that.

Yes better change the type of pistons as they must be rubbish if otheres have had problems to.

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Well i feel for you mate, as you say seems to sound like a manufacturing fault!

-MINI CLUBMAN 1380 TURBO-

clearley thes pistons are Crap!

get ya money back and go for some accralite forged ones or some omegas

What happened to this topic then?
http://www.turbominis.co.uk/forums/index.php?p=vt&tid=135341

Back once again like a renegade master

i like the bit when it says about the problem area of the rings lands.

any way now drinking plenty of red wine to null the efect of earlier.

but i still recon that it is because at the back of the ringland its square were i think if they rounded the edges it will make it stronger.

always looking for them bigger bunches of bannanas

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MikeRace, Mini13

thanks minimadj ......lol

clearley these pistons are Crap! and these "ones are" of hoggys

Sorry Steve,
Sorry to say Im jus glad hogster busted em to show me before i forked out 250quid on a shanked set of pistons.

Back once again like a renegade master

Hi,
Are these the same as the hypatech ones on ebay?
Cheers,
Gavin :)

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accralites or omegas not heard many,any, troubles with the lands breaking

I've got the mega pistons in mine. Never had a problem.

What i will say, is that the area above the top (missing) ring looks like one that has seen rich (dare i say over-fuelling?)
Exactly the same appearance as when I took a similar ring land out of my omegas (i think) several years ago...

Edited by TurboDave16V on 4th Sep, 2007.

looking at the way it has come appart when i zoom in, i would say there has been some sort of balls up with the manufacturing process perhaps a hairline crack, the top section looks like it has failed, then the rings etc have put extra load on the next section down which has caused the other failure, just my opinion tho.

At least u didnt take out the block to hoggy accralites are the future imho :)

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MikeRace, Mini13

Here are (were) my omegas. These are combintions of pics of two pistons.

http://www.turbominis.co.uk/index.php?p=14&album=714

Something does make me think you need to consider this as a possibility; your mini was set up on rollers for higher boost than you ultimately ran for some time as you'd inadvertantly installed a class Z restrictor (lol)...
Hence - you must have been overfuelling?
By how much is I guess only determinable if you had a decent wideband on display?


Of course - yours and TurboTel's AND TurboEstates (IIRC these were MEGA also) experiences are not a good sign, but it 'could' be a coincidence as the postmortem on all of them appear to show a very rich pattern above the top ring.

Can I just say, that from all these piston failures that i have seen (fortunately not experienced) there seems to be a pattern emerging. May be its something maybe its nothing, but the majority of failures, the damage is across the pin, IE it is on the sides of the piston that are not in thrust and where there is little metal between bores to take the heat away. I noticed this on pistons that have suffered det failure, Will and Bens TT2 last year for instance. and also now those that Dave has shown us.

The pistons are a little narrower in this area to take into consideration the difference in expantion rates of the extra mass around the pin boss. Maybe something to take into consideration?

I would be inclined to say that it is detonation that has caused this, but that is my opinion, and if it's not it has to be a failure of the design.

Also was there not a topic around somewhere in the theory that people could post up their breakages all in one place to show what has done what and why

Edited by Sprocket on 4th Sep, 2007.

i had set set of AE pistons that did this and that was due to over fueling. (home brew fuel inrichment injector, far to big!!)

could the part of the piston that has broken be under the squish area where its deepest ? if so ,could the excess fuel be sufficient to hydraulic in the area between the top ring and the head face ,and so break the land ?

incedentaly , detonation tends to melt things or make them sieze ,which does not look like its happening ,whereas pre ignition tends to shatter things ,specially cast and hyperutectic pistons ... dave ,where yours the cast ones ?

something else i notice is that there seeems to be no bore running marks on the sides of the pistons , if the bore clearance was a bit big this could produce more load on the top ring because more of it is exposed ..

it would be interesting to see the chamber colour and the top of the piston ,and how much boost and what timing etc etc .

lots of coulds and maybes in that lot !lol

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

http://www.tpub.com/content/engine/14075/css/14075_102.htm

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

^^^^^^ Lots of good points from Robert there.
btw - the Omegas in my picture are the cast ones Robert...

Edited by TurboDave16V on 5th Sep, 2007.