Hi all. I've been looking at an ad that says "This car was owned by a mechanic and I have been told that the engine is fully forged with Cosworth pistons etc, but sadly there are no receipts we cannot verify this."

So, being a sceptical type, I wondered if this could be verified, perhaps with a boroscope/borescope or similar?

 

I think it would be pretty hard to tell without physically seeing them! You'll know if it's had a rebuild as most forged builds have very light piston slap noise when idling. Although that still won't verify the type of pistons I suppose....and I would be reluctant to assume it's had a good standard of rebuild without the paperwork or detail.

 

Yeah those are my thoughts to be honest.

 

Had mine checked with a boroscope.assumed to be forged,sent pictures to many engine builders who agreed they looked like forged items.managed to track down a previous owner and got paperwork for a forged build using cosworth pistons.good result!

 

Try and find out where it was done, maybe the builder would have some paperwork?

 

I bought a car last year with a forged engine,built by a reputable builder,using cosworth internals,all reciepts present etc.
Engine didn't last long tho,Piston failed and the others had fracture lines so were ready to let go.
You take a chance either way tbh
Read some bad reports regarding Cosworth pistons(after I bought it)
I'm sure some are ok but personally would not use cosworth pistons again due to my bad experience.
I do think the failure was down to bad mapping tho as the Pistons did show signs of det,confirmed when I plugged it in,the det was pretty bad.

 

Assume nothing unless you've got paperwork. If they've lost the invoice the only way would be to contact the firm that did the work directly.

 

what year and car is it?

cosworth and some mahle forged pistons have a square shaped dish on the crown whereas standard newage sti pistons dont, this should be easily identifiable using a bore scope, that said i believe the earlier classic sti pistons also had a square crown so maybe a bit harder to tell on them.

 

without receipts i would only pay standard car money
-a forged build or just forged pistons?5k miles ago or 75k miles ago???-a rebuilt forged engine mainly only benefits from the fact that it normally includes an engine rebuild at same time. so starting with a zero miles engine again - new oil pump?-new crank?-fresh bearings and clearances?heads refreshed? standard or uprated rods?
without any receipts what pistons it has is irrelevent really. lot more to refreshing an ej20-25 engine than just the pistons.