stevieturbo

I bought these pistons from a guy in the UK who had them custom made by Ross over 18 months ago.
They are for a std bore LS1, 0.944 pin to take a std LS1 rod with a fairly big dish for low CR ( too low, but anyway ).

Ive only just started to assemble this engine, but come across a nasty problem. The pins are a press fit in the rod, and I had them fitted locally. They were not pressed in, but the rod heated and pins hand fitted.

As can be seen in photos these are brand new.

Is this a crack ? or some strange mark ? It unfortunately does look like a crack or casting flaw of some sort.
Im assuming this piston is scrap ?



[

Photo taken using mirror ( trimmed to size, mirror has a crack, but piston mark is clearly seen ) )


Whats the story with this ??

Avengeance

iTrader: (4)

I wouldnt use it... that sucks.

Adrenaline_Z

The crack shown doesn't look too pretty. I wonder if there might be a burr
cutting into the pin?

I'd also question the pitting seen in the top photo.

stevieturbo

Pitting where ? Theres a little bit of dirt on the pin from the cloth I wiped the oil off to take the photos...

The piston runs smoothly on the pin

goober35

iTrader: (1)

That is very odd. Most of the time when a piston cracks it cracks all the way across.
IMO you have a very exsensive paper wait.

stevieturbo

I'd understand a crack if they had been used or something. They are brand new. They've just been lying since I bought them ages ago.

strokedls1

iTrader: (1)

You could get ross to make you one to replace it. It would be easy if you have the spec sheet. I definitely would not use that one though.

stevieturbo

They want to speak to me on the matter, although due to time difference and the weekend havent been able to yet.

TBH I dont even want to be using these pistons, but I have them, and dont want to be spending any more money.. I bought them over 18months ago, and at the time knew little about the LS1, but bought them with lots of other parts. With hindsight it was a bad move. They were made to suit stock rods, which means there are virtually no aftermarket rods that will work ( 0.944pin )
The dish is massive at about either 30 or 34cc. The guy who had them made wanted a ridiculously low 7.0:1 or something crazy.

Ive tried messaging a few sponsors about a cheap rod/piston package for a more sensible 8.0:1 CR or maybe a tad higher. Still havent got a response from any of them yet though. Though anything I get must fit a stock bore size. Any local machine shops wouldnt even know what a deck plate is here, and would probably **** up boring/honing to suit oversize pistons.
Im pump gas only, and pump gas in the UK isnt as good as what you guys get over there. 8.0:1 should be good for 20psi or so though...which would be cool. probably 15 or 16psi will be enough though.