and most of them are four letter words. Found a couple pieces of ringland in my oil pan when I ripped into the motor to resolve my headlift. Upon further investigation I found what you see below. a single piston, all other 5 are fine. Car ran 100% fine beyond the headlift issue, so in a sense I am lucky to have found this.

Going forward, inspection of the rods and crank, new pistons, and cams w/some light headwork

These are standard arias pistons:

 

WOW I can imagine the 4 letter words and more, been there.

What caused it? ring gap too small?

 

How much boost were you running when you noticed the head lift issue?
Good Luck getting that think back together. This motor build down time really sucks.

 

Talking with a few different people/shops, I am thinking too much boost paired with too weak of a piston. what you see above maybe the exact reason we now have arias ED pistons

 

Started getting signs of headlift when I was pulling 17 psi at redline.

 

I would be surprised if it is too much boost, unless it is too much timing with the boost, the pistons should be able to handle 17 psi, as for the extreme ED pistons are basically drag application pistons used for street cars and those guys see 50 psi and more.

I know it is a different application but the Japtrix EVO with Wiseco pistons is tuned to 30 psi and no issues.

 

Bummer....that was on a stock block wasnt it ? How many miles ?

edit.....from the above post ..you were built . Even more of a bummer !!!!

 

I have talked to a local shop, more than a couple board members and such and all come back with most of the same type of response relating to a weak design. The ringlands are very small. This doesn't seem to be tune related - as there are no signs of detonation on the tops of any of the pistons. I am also running the hks AFR/knock amp and any spark detonation that would occur severe enough to cause this would be picked up by that....at least I would hope it would

 

Hope everything works out for you Aaron.. kinda strange standard Arias pistons are weak... and stock VQ Pistons never had a problem only the rods

 

maybe in a situation like this, the stock rod is weaker than the stock piston??

No worries, a little machine work and a new set of pistons and we will be rolling again. this is basically another couple hrs of work to pull the lower end apart because we already had the heads off, so relatively speaking, little added cost there

 

It's DEFINITELY a tuning problem. VQ guys need to stop worrying so damn much about peak torque and getting it to come on so fast and hard... and worry more about keeping their motors alive. Put a nice smooth dip in timing where you make peak torque and wherever boost builds/rpm rises very quickly and the motor will last you longer and the power will probably even be easier to handle.

 

please do let us know the condition of those eagle rods... there's still some debate on the power level those things can take... i think we're good to much more than we're pushing now...but, i could be wrong...

 

You are welcome to discuss tuning strategies with my tuner. I don't know your background, but I know my tuner is well versed in tuning the VQ

 

Yup...the very reason we developed the Arias ED piston almost 2 years ago. Thanks for sharing.

 

There are pro race teams running FAR more boost than 17 psi on pistons other than the Arias Extremes FYI...I thinkthere are other factors that may have caused your failure.

 

Soory to see that man, Good luck!!

 

Agree,broken ring land on a froged piston.you got to look deeper into the cause .i don't think it is a week piston .

Sam

GT MOTORSPORTS

 

Yup.we are constantly tuning stock 4g63 EVO engine up to 30 PSI with GT35R turbo making 500 to the wheel, again stock pistons .very simple you can't let detonate .my point is with the proper tuning you can really get a way with a lot .

SAM

GT MOTORSPORTS

 

I will discuss with the machine shop, maybe he can provide some insight

 

Remember its 17psi with two turbochargers worth of airflow. If you calculate the mass air rates of both APS turbochargers at that boost level, it would be the equivalent of a single GT35xx running at about 30psi boost pressure. Arias recommends a max of 20psi boost pressure on the standard duty piston (single turbo), but it really should be calculated in terms of airflow, rather than pressure.

Certainly, tuning could have something to do with, but IMHO, you need a stronger piston that is better at the limit, which gives you a larger margin for error....particularly when the car has left the shop, and now is in the hands of the customer, with all the variability that can come with that.