could any one help im rebuilding my 2wd cossie with a 205 block,0.5 pistons,reground crank ,all new bearings,gra rings ,but i have a problem i brought a set of second hand pistons from ebay, the numbers on 3 of them are yb0883 and the other 1 is yb1130/01. The pistons all look identicle but the one with the odd number has 4 little cut outs by thr rings.
Does any one know if there is a problem with this one or if it is just the way they came,the pistons were supplyed by ggr and the part number on the tube is ggr253
cheers for any help

 

im not really sure m8 , but i can tell u the numbers on my piston sets all match up ! do they have any other numbers or valve clearences cut out on em ?

 

So are you saying 3 have a flat piston surface and 1 has valve cut outs?! If so be very weiry using it as all 4 pistons have to be balanced to work effiencently.

Pics would help if poss!

 

no all crowns are the same its the side that has the cut outs proboly the 3mm by 2mm and 50p shape the holes are just under the oil ring

 

Best thing to do mate is take em to a machine shop and make sure they are all balanced ok, of they are shouldnt be a problem

 

sounds like one of them may be a 4x4 one, and the rest 2wd..
the one with holes/cutouts by the oil ring - 2 each side? 4 in total?
4x4 pistons are like this.

 

yea but if 1 was 4x4 and 3 2wd you would see a big difference as the 4x4 ones have a bigger bowl in the top.

 

yeah, didn't think about that darren.. although I'm not sure the difference is that big until you look closely.. worth a closer look to confirm though

 

you would know if you had them next to one another
the bowl is almost twice the diameter on the 4x4 ones

 

ah, is it that different darren? i didn't appreciate... thanks, learnt something today

 

here you go,
the top ones are 2wd and the bottoms 4x4, you can see the flat bowl in the top is bigger on the 4x4 ones
<img src=http://img2.photobucket.com/albums/v11/darren.cudd/2wd.jpg>
<img src=http://img2.photobucket.com/albums/v11/darren.cudd/4wd.jpg>

 

 

Ash
have the pistons all got mahle written on the inside of em ? its normally on the underside of the top !!

 

Yes they have all got mahle and all look identical apart from the 4 little cutouts

 

sounds like one of ya pistons has piston worm to me mate
those pesky little buggers!

 

Its definatly a strange one m8 ! i take it all the pistons have the 00.05 stamped on em aswell ! if so i think its gna be a case of phoning ggr and gettin em to double check the part numbers 4 u . or of course u could allways buy a set of highly sensitive weighing scales and a vernier guage and check they are all the same !

 

no they havent got 0.5 stamped but have all got a + after the numbers