GZE forged pistons v aftermarket forged pistons

[The Witzl]

I dont think i personally know of anyone who has broken a ringland on a 4A-GZE piston.
The only 4A-GZE piston i personally know of being broken is feral's bigport gze piston that was given to oldcorollas to analise in the threads that Ed linked to above. It had seen a hard life, with poor tuning too if memory serves well?

[30psi 4agte]

I had wondered why my ears were burning

We have plenty of info on here about these suckers.
I personally like the 4agze pistons and like i recently said in talasas thread they will be my no.1 choice for my next engine which will run 40 psi and make the one i have now look std !
I have that much faith in them!!

I think the conclusion we all came up with last time was ....... It doesnt really matter what the pistons are - semi forged / forged / cast they have been PROVEN to take an ABSOLUTE hammering and still come smiling

A few of the you guys know of the major engine failure i had playing with nitros but some may not so here :

After making 283rwkw numerous times on the dyno we decided to give Nos on the cooler ago. Lets just say it didnt go too well!! The nos went straight through the cooler and the radiator and was sucked into the turbo (ABENTLY it was aTurbonetics T60-1 at the time )
I ended up lifting the head from the block , melting the head in the no. 4 cy and having 30 psi go into the cooling system and blow the header tank clean off the radiator! Needles to say a major f##kn mess on all my polised alloy . Anyhow After pulling the engine down and expecting to find major carnage i found that the piston and rod were still perfect!! ( could not believe it)
This has started me thinking what the hell will it take to break one of these suckers?








This is the link to thread that has more talk on these pistons. Its worth a read when considering 4age pistons

http://www.toymods.net/forums/showth...ghlight=piston

[feral4mr2]

I dont think i personally know of anyone who has broken a ringland on a 4A-GZE piston.
The only 4A-GZE piston i personally know of being broken is feral's bigport gze piston that was given to oldcorollas to analise in the threads that Ed linked to above. It had seen a hard life, with poor tuning too if memory serves well?

indeed a hard life.. haha.. but there was no tuning at all to be exact, was my 1st 4agte with gze stuff, advanced timing and a shitty i/c spending too long on a high speed cruise.

i have seen personaly another 8.0:1 c/r piston (3 in fact) top ring land curl up. luckily for my mate i had 3 spare (the other witzl mentions) and rebuilt his engine overnight in my garage so he and his wife could get home (700 odd k's away)..
i have pics of said pistons somewhere.

[abently]

......30 psi go into the cooling system and blow the header tank clean off the radiator!

I think you will find that on the Compression cycle + Ignition, it would have have 300+ psi going into your Cooling system.

Thanks for the info though, can you post pics of the Pistons with the curled Top Ring land ?

[Talasas]

I had read enough of all the efforts of these fine lads to make my choice when it came to choosing pistons. I think what you can gather from this albeit sensitive issue is that they are more than suitable for most people's needs and that is all you really need to know.

Particular credit can go to 30psi who has seen a lot of this first hand which is more than a lot of us here can say remember that.

[bigstickerperformance]

i had an engine failure occur at the track bout 5 months ago,it has been hard to blame it on one particular thing as i have found some rather disturbing problems with it along the way....but anyway i was making 200rwkw with a gt28r and completely %$# the motor,lack of oil pressure has spun all the big ends,but more worrying is the fact at all the pistons had cracked ring lands!,my engine bloke has said most likely the ring gaps have closed up under extreme heat,but i also see some slight erosion on the top of one -detonation??,the engine was supposedly tuned close to the limt but safe i.e some timing taken out...
so yes these pistons will break
can post pics if you want
Ryan

[abently]

i had an engine failure occur at the track bout 5 months ago,it has been hard to blame it on one particular thing as i have found some rather disturbing problems with it along the way....but anyway i was making 200rwkw with a gt28r and completely %$# the motor,lack of oil pressure has spun all the big ends,but more worrying is the fact at all the pistons had cracked ring lands!,my engine bloke has said most likely the ring gaps have closed up under extreme heat,but i also see some slight erosion on the top of one -detonation??,the engine was supposedly tuned close to the limt but safe i.e some timing taken out...
so yes these pistons will break
can post pics if you want
Ryan

Did you ever Flow bench the Head with the Inlet Manifold on it ? As you'll most likely find that Detonation was probably caused by the Variance in Flow across the Cylinders with the Tuner running the setup on the Leaner side.

I'm assuming the Oil Squirter's weren't working with the lack of Oil pressure either...

[kickn5k]

Hey guy`s
I make aftermarket forgies, they i feel are works of art(yes im really biased), but if i were building a 4agze/te and i were put under this question i would have to go for the factory part myself. These things are a awesome value for money bullet proof "to an extent" part that are cheap to replace one if needed.
Also dont forget a turbo grind set of cams will usually lower comp a little too, it all helps to keep things happy, and they unleash more power too.
As with any piston detonation and heat will eventually kill it, so a rich tune always helps.

stu.

[Mr Revhead]

oh noes not this again!!!

4agze are FORGED from HYPERTUETEIEICIEIICIEE (shit thats hard to spell) material

forged = prosess
hyperhardtosay = material

when considering what pistons to use
as always with enignes, whats the application? what REALISTIC power are you going for?
would have to be a damn serious engine to warrant aftermarket pistons

[oldcorollas]

i brought that piston back to japan with me
i will be doing composition analysis in august when i get back from a conference.
i will try to positively identify the coating also.

the word you are looking for is hyper-eutectic... ie.. more silicon than the eutectic composition

[legend]

so what rings would be the best for the gze pistons

[Billzilla]

so what rings would be the best for the gze pistons

Toyota rings.

Hey how about we just call them Hyper-enthusiast pistons, that's easy to remember.

[Mr Revhead]

nice one old corollas, looking forward to read the results on that one

bill, im with you!!!

[The Witzl]

i just call them hyper-euhektik pistons.....

[oldcorollas]

preliminary results are in.

this was done using an x-ray element analyser... ie, quick and rough, but within a few % for most elements

the alloy has aluminium (duh), ROUGHLY 18 weight% Silicon, 1wt% Copper, 1.2wt% Nickel.
the alloy is almost defintiely hyper-EUTECTIC ...
it's not the usual 4032 alloy, but... not sure .. unless free-silicon particles are artificially bumping up the content perhaps?

now, the coating.....

by using this machine, it also goes thru the coating to reach the alloy surface... however...

1 major extra peak was found compared to the bulk alloy (and a minor one, but i'll get back to that later).
the aluminium/silicon ratio remained the same, showing that neither is part of the coating.
nickel and copper both increased by about 1wt% (to 2.2 and 2% respectively).. are they in the coating? perhaps, but hard to tell.

but the major peak was Sulfur and/or Molybdenum.
the Sulfur K-alpha and Molybdenum L-alpha1 lines are almost on to of each other, so i could not distinguish them in this machine.....

but it looks like the top coating might moly sulfide?
i'll see if i can run any other tests to confirm MoS2