Hi all and happy new year

I removed my pistons and saw that they are cracked from the bottom.

Did someone ever had this problem?

Thanks

 

Pictures?

 

It needs replacing. Strange though ...

 

That is very weird never seen 1 crack there

 

what piston?

 

Arias

 

What was the p2w? Pics of the skirts?

In that picture the front and back of the piston looks messed up.

 

That is a Piston to wall clearance issue right there.

 

The p2w clearance was according to specs. This engine was running the whole season

 

The piston is messed due to the crack
After the crack, the piston obviously had a p2w touch

 

Do you even know the p2w?

 

They are according to Arias specs for sure but
I ll give you the p2w later as I have to go to the workshop

 

I do not want to blame Arias at all as they are good quality.
I am just checking the cause before the next built as I am going with Arias also

The thing I want to say is that I think that this damage came, first the crack and then the crack caused the piston to touch the wall

I was running this P2w for this last season, more than 90 runs.
Last month I removed the head for checking before last event and walls where ok.
These last runs that something happened

 

If thats the case then did you do something different on the last few passes it made? for example did you turn the boost up, or run a different weight oil., ect? My guess is that something added previously unseen heat to the piston causing it to expand further than normal and make contact with the wall. Once contact was made it cracked and continued to make contact.

 

No same boost level, just changed oil brand if it makes difference. Same grade and viscosity but different brand

 

Is that the intake side that is cracked?

 

Can you freely move the pin? Based off that picture there was Def p2w issues before that crack.

 

I'm with you.

 

There is a stress riser on the piston strut that needed to me removed on the off the shelf Arias B series piston.. The crack starts there.. Its not a machining/P2W issue

 

had the same problem with some manley pistons , 3 pistons cracked at the same spot and one actually broke , my machinist said the cylinder walls were out of round and thats the reason why it happened.

 

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Post a pic of the other side of the piston.

 

Yes

 

Yes pin can freely be moved

 

Seen Manley's do that too.

Full strutted piston FTW.