After just 1000 km my #2 piston and it's piston ring is already damaged on my brand new shortblock ,broke in the car with mineral oil and low boost, any clues?
Read here that many pistons go on these blocks, I had a big end failure on my standard classic block, now this on a new short block, why do we think these are great cars??

I am fed up and thinking about selling the car but first have to run in the new piston and new piston ring, do I need to follow the usual breaking in procedure again i.e. mineral oil and low boost?
Would it be better to replace the liner at the same time so that the whole new unit can be broken in together? I fear that a new piston and ring dont seal properly in an already broken in liner.

Plsd to hear.
Tnks
Frank

 

you're a bit scant on details, year and model of car, was the engine builder a recognised and reputable company or home built jobbie

. Type of engine block fitted, did you have different piston/con rods bearing fitted?

What boost pressure are you running with which turbo?

Which ECU?

Andy

 

Sorry guys,

It's a US sourced brandnew shortblock with factory warranty, all other components come from a 2004 Jap spec STI engine, I think it has a VHF 35 Turbo?
Standard pistons and rods, during first 1000 km only 0.5 bar boost, standard ECU with Ecutek remap, professional workshop.
Engine fitted into a '94 WRX, all wiring now basis 2004 STI incl 6 speed DCCD.
After about 500 km engne did not run idle properly anymore and first few km on 3 cylinders only, once hot 4 cilynders but stil rough on idle.
Changed plugs and injectors but still bad idle, checked compression and found #2 low.
Opened engine and found damaged piston #2 and broken ring.

Rgds
Frank

 

what fuel do you have over there Frank? and hello.. long time no speak.

Simon

 

Hi Simon,

Good to hear from you , we use 95 RON in Thailand, my Ecutec mapper has been in the Thai automotive industry for 25 years so dont think that's where the problem lies (I even have those mysterious Broquet pallets in the tank for what it's worth) and the computer showed that the airflow ratios were ok.
I will have a look at the piston tomorrow and take some photos for further debate, any ideas in the meantime most welcome as dont want to happen it again.
Suppose I go for forged psitons which would you recommend? I saw your were talking about the Wiseco pistons I think.

Cheers
Frank

 

Can you take a picture of the damaged piston? and has it damaged the bore?

need to establish why it went really.

Simon