New Engine Blown Up At Tuners

[tridentt150v]

Nah more likely be excess heat, insufficient ring end gap or collapsed ring lands/ pitted sides etc..

yeah your proabably right, but I've seen an oval bore before [but not in a turbo nissan I have to admit] where the rings are compressed at the top by the tight cross section and then you get big blow by for the other 80% of the cylinder where the rings aren't touching the bore. And those scuff marks are typical of this. And that is an 'induced' ring collapse.

Also if this happens then your ring end gap is shot to hell and back as well.

[joe blo]

well i got it pulled down at shop. no signs of detonation. 4 broken ringlands. says it broke from too much boost (17.6 psi). pistons musnt be comparable to the genuine nissan ones like i was hoping

Edited September 4, 2011 by joe blo

[Dobz]

STATUS wins 1 free interweb!

Are they some sort of aftermarket cast piston?

[joe blo]

yeah there mahle cast pistons

[Dobz]

Yeah you'd think a company with a reputation like that would make a quality cast piston. But that being said a cast piston genuine or not is a gamble with reliability even if they are new.

[O2 Autosports]

please explain how there is no sign of det and yet broken ring lands?

[joe blo]

not strong enough? somethings gotta fail if they cant handle it. weakest part possibly? i dunno

[joe blo]

it did make over 3 times the power than the application theyre made for lol

[joe blo]

[SargeRX8]

please explain how there is no sign of det and yet broken ring lands?

Can someone tell me what all these parts are? I know you have a piston but I hear stuff about ring lands, crowns and all this stuff. I know the piston ring must be a seal around the thing but what are the other parts of the piston? Does the top of the piston have a specific name?

[D_Stirls]

Can someone tell me what all these parts are? I know you have a piston but I hear stuff about ring lands, crowns and all this stuff. I know the piston ring must be a seal around the thing but what are the other parts of the piston? Does the top of the piston have a specific name?

The crown is the top of the piston the ring lands are the gaps between the rings and the skirt is the section below the bottom ring.

Here's a diagram for you;

Edited September 4, 2011 by D_Stirls

[r33_racer]

Seems to be broken on the thrust side. Did he explain why? Also, is that the exhaust side or inlet side we are looking at there?

[methz]

i run 26psi thru stock 2nd hand pistons here.. 3yrs old still working..

[Rolls]

No doubt you have the tune and temps under control, these things are crucial when running big power/boost with stock pistons.

[MrStabby]

So... do ringlands break due to excess force exerted by the ring (either from pinging or just tons of power & boost) ?

OP do you know what power the pistons are specified for? Will you contact the manufacturer for comment on the failure?

[joe blo]

So... do ringlands break due to excess force exerted by the ring (either from pinging or just tons of power & boost) ?

OP do you know what power the pistons are specified for? Will you contact the manufacturer for comment on the failure?

thats the way the guy explained it to me. that they broke from too much boost pushing down on them by the rings.

dunno what power there rated for. there only n/a replacements. was hoping theyd be same as nissan pistons where ya can make heaps of power on em and lots o boost. nar not gunna contact the manufacturer about them

[The Mafia]

Boost pressure has absolutely nothing to with breaking rings. Combustion pressure does.

You could fill the cylinder with 200psi of boost and it wont worry the rings. Put some fuel in there and light it, and thats another story.

Things that make combustion pressure too high = detonation, pre ignition or water.

[The Mafia]

Oh, and did you get the chome-moly top ring? It's for turbo applications.

NA rings will do pretty much what you've just experienced.

[joe blo]

the rings arent broken. they still good

[Legionnaire]

Boost pressure has absolutely nothing to with breaking rings. Combustion pressure does.

You could fill the cylinder with 200psi of boost and it wont worry the rings. Put some fuel in there and light it, and thats another story.

Things that make combustion pressure too high = detonation, pre ignition or water.

Absolutely. Chamber pressures are indeed affected by boost pressures, but boost is not the only, and not the major factor in resulting chamber pressures.

Overadvanced ignition timing and preignition (mixture ignited by hot combustion chamber parts prior to spark) can cause very high pressures without any audible pinging.

What was the compression ratio in this engine?

Edited September 5, 2011 by Legionnaire