my engine has been in my car for the past 4 years. i first noticed the piston like this 4 years ago when i had the head off.. but ive been running it perfectly fine every week like this for the past 4 years. it doesnt look good at all but it has awesome compression and doesnt burn oil and the car runs 10's lol...but im still curious why the pistons are like this. i have the engine out right now due to a spun bearing but im going to continue using these pistons.


thats the intake side of the piston by the way.. both number 1 and 4 pistons are like this.. 2 and 3 are fine. and they are arias pistons.

 

p2v contact, could cause you to shatter a piston

 

its not p2v.

but it could be i big restriction in the EX. makeing that side of the piston to get supper hot and blow pices off the valves relifes and the side of the piston

 

No, looks like detonation. Probably very mild if it lasted 4 years and still had good compression. Detonation usually attacks the very edges of the pistons just like the area in the picture and the ring lands. Lucky for you it wasnt strong enough to damage the rings or ring lands but just started eating away at the piston.

 

Maybe its just the phone im looking at the pics on, the the relief looks like it has a extra ridge in it where a valve has been tapping.

Using a Sidekick to go on HT sucks

 

thats what i was thinking but wasnt sure.... about 4 years ago i was having a problem with pushing coolant because of detonation because i was running too much timing at the time..

not p2v..nothing wrong on top.

 

Dang, other than that area, the rest of the piston looks perfect. Even after running it for 4 years. Thats pretty cool.

Possibility could be that it got damaged early when you had it with too much timing. It could have just worn out through the years after so much use..

 

yea im pretty certain thats what it was... the other 2 and 3 pistons seriously look brand new.

exospeed definetly did an awesome job building this engine almost 5 years ago...im rebuilding it right now..all same specs.

 

you should smooth it out with sand paper or maybe have them coated...to eliminate any chance of a piece breaking off...

 

yuppers.....way back when i was running the fmu ( yeah yeah yeah this was 01) when the engine got lean, thats where it got attacked. usually at the thinnest part of the top. around the valve releifs. once it ges in therehas the blow torch effect.

 

Is this type of damage is audible on a typical street setup?

 

Looks like det to me, det cans should have picked that up while tuning, if its only happened on one cylinder be worth while checking the injector is in good working order for that pot?? As said may have happened years ago in the past while tuning..

 

I would like to see apic after the piston was cleaned up well, not like scuffed or anything just maybe wish a light soft wire brushing. The thing that gets me is the skirts looks outstanding, not a single scratch or wear mark on them which to me kind amakes me lean as if it did not have a ton of timing in the motor.

How old are the injectors, and what are they also what injector driver do you have on them, last ly what engine managemnt

 

its funny cuz i took a motor apart last week of my shop fresh motor of a customer cuz of a sun bearing too and the piston looks the same way, but not all the way across like yours. you could sings of the same deterioration of the piston and its the same brand arias i dont like to bad moth companys specially a known name like areas but i think is just the material they use its no good for boost maybe allmotor its fine but not boost too much heat for them....i put the motor back together just that and its still running for now lets see how long it last.

 

he did put the car on two step a lot.....every day he drove...maybe that could be the cause...do you 2 step ur car alot??

 

Not to bad mouth you, but it seems like you're assuming before knowing what the issue is. Do you really think that a companys product is no good for Turbo when TONS of people use those pistons in boosted motors. We personally use Off the shelf Arias pistons and pushing 900-1200 on them at the moment for B and H motors and dont have these issues.
There's more to detonation than the piston itself. So many factors such as injectors, manifold design, tuning, etc. Good luck to the rebuild OP.

 

the pics above were after i went over it with a scotchbrite pad.

yes the skirts are perfect. hondata s300, injectors are the same ones this motor has had for the past 4 years. the engine runs fine for the past 4 years on these injectors and 10 second passes, nothing wrong with them.

it was the timing that was causing me to detonate and push coolant/lift head 15 or so times. i turned it down and problem went away. and im still running more timing then any other 400hp d-series out there even after i tuned it down...