I've got a GE 84mm 2.0 b18 block being completed at the machine shop as we speak
and seeing this makes me VERY nervous.. I'm running CP 9.8 comp pistons and knew of this happening but thought it was all done and over with by now.. Aren't there tons of motors getting thrashed on every weekend out there holding up with cp's?? If so please post so I can
sleep tonight

 

Yes. there ARE tons that still use CPs everyday. I'm seeing that there are some commonalities with problems in terms of detonation, fatigue, HG issues, etc. But it can happen to a lot of companies.

Not sure what to say. All companies have some weaknesses in terms of metal fatigue. This may be the weak point: detonation. But I just don't think its a pattern enough to be concerned about. the law of probabilities has always shown this to be true. For ever 3-10 bad ones, there are thousands that do well.

 

The most difficult thing to determine is what occured first...

A piston that is erroding away, will create localized hotspots at the edge of the broken piston, thus, it will increase the chance of detonation double-fold. If the piston is beginning to break apart, then it will create all those symptoms of detonation afterwards.

However, prolonged detonation will always show marks on the piston tops and the cylinder head. This doesn't seem to be the case at all based on the pics.

From the OP, timing and AFR was good, plug heat range was good, and water/meth was only added with no change of tune.

There is a reason why all the newer Wiseco pistons have that thin spot totally milled down.

 

Those weisco pistons tend to do that . My buddy had same ones in his sleeved block and huge chuck broke right off in the same area but a much larger piece

 

You mean the OLD wiseco's tended to do that, though i've never personally experienced any problems with either of them.

 

Yes sir old ones. Wen were the "new" ones made this was about two years ago

 

To me it looks like the design is still somewhat flawed, this is a new 83mm 9:1 cp, the valve relief area is really thin to me

my JE's were not like this. I talked to cp today and they obviously blamed the tune. I thought the reliefs were revised from a few years back

 

I wouldn't be surprised if they were just getting them stamped in china and the final product is finished here in the states to be honest. That would explain the casting problems. You would be STUNNED at how many "performance" companies order the unfinished casting for pistons, rods, cams, etc from a chinese metal working manufacturer, and then finish the work here. Crower stuff is the same way, made in china, and finished to spec here in the states. (shot peening, boring, honing, measurements, etc)

 

Oh, c'mon, man..Stop it..don't go that route today. Everything is made somewhere else except in North America, we all get it..Please, just don't turn this into another geo-political debate about who made what, where. We're all considered "imports" in the minds of all others that have a similar base as this type of thinking, and it helps no one solve anything.. really.

Nothing is from the U.S. anymore, and anything else is left to the quality control of the representative company itself. Putting a "its China's fault" label on something that has multiple logical explanations for its demise; It just doesn't solve anyone's issue at hand for the here, and now. I know H-Ters like to immediately point the finger and place blame on the other guy, but this has just gone too far in the last 15 months.

 

lol Im not turning it into a geopolitical debate, merely a quality control problem. There are plenty of GOOD chinese manufacturers, same with taiwan, mexico, etc that have good quality control and good manufacturing processes. I actually work for one of them in the computer electronics industry, so I have first hand experience with the chinese manufacturing process. However there is a much larger number of companys in china that do some very poor casting work, and I know first hand how shitty the castings can be as ive experienced it on several occasions. Obviously that cylinder took some serious detonation to cause that, but that still doesnt mean that there isnt a potential casting problem thats being overlooked with CP pistons compared to the rest. They all seem to be breaking in the same spot.

 

I'm glad you're at least recognizing this issue (as so many don't and hop on an unfounded bashing bandwagon), but since neither of us have any in-depth knowledge of even the remote probabilities of a QC issue being the case, until there's further reliable information, let's not stretch this far for reasoning ok? It may be bad design or bad material choice, WE DON'T KNOW. so let's not create facts from this. That's how BS unfounded rumors get started on this site....from complete and utter speculation nothing more.

 

For the amount of 'abuse' this motor has taken I have more faith in the oem pistons, I ran a stock gsr setup at 320hp for years, since 2004 till last year and still nothing wrong

 

I hear that, and really there's no way to tell to be honest. Those pistons could be perfectly fine, and still have a manufacturing flaw, under normal operating conditions, and you would never really know it until they are put under the abuse of a detonating engine and vice versa, there could be nothing wrong with the pistons and the detonation was just so fierce it destroyed the piston. What makes me wonder is, what caused the detonation?

 

It doesn't surprise me that people are giving advice and answers without even being able to tell what aftermarket sleeves look like. There is not enough solid data presented to truly evaluate and determine what happened.

We all know its the weakest part of the piston, so it will be the first part to fail. Generally speaking when I see pistons in that condition its caused by a combination of high heat and detonation. I would reconsider your tune and power levels on pump gas.

 

still my gut feeling.

now i know its not a honda but i have a friend who made 568 on pump/meth with his evo like 2 years ago. it would get hot enough to crack the porcelain in the spark plugs...for longevity i dont think its worth pushing the limits. if you want that power on tap daily look into e85 if you have it available.

 

Yeah I see too many inconsistencies on pump gas to be comfortable pushing it hard all the time. Personally, i'd rather play it much safer and enjoy the reliability of a well though out setup that lasts.

 

http://rushi.kapsi.fi/pics/mazda/supertech1.jpg

How about smoothing the sharps off?

 

My new engine is ruined as well.... 84mm CP 9.7:1 pistons. Detonation looks like the culprit... Funny thing is, only 75 miles on the motor. No boost (bypass valve zip tied open) and no VTEC. I just sent the injectors off to RC to have tested. It was my number 4 cylinder that came apart both on the stock ITR block/pistons and the Benson block/CP pistons. My guess is a clogged injector. Running RC 550cc Saturated injectors that are about a year and a half old.

 

Mine was a new build as well, cyl 4, maybe 100km on it. Brand new ID's on it

 

have a nice day