I'm doing a full rebuild of my 125 2.4 TDDI engine. I'm part way through the build and took delivery of the pistons rings earlier this week. When I ordered the rings from a well established local engine builder he asked me for the size of the rings. Obv a fare question. I picked up the piston and measured the thickness with a vernier.... top ring was 2mm thick, 2nd ring was also 2mm and the 3rd oil ring was 3mm. All the rings he supplied were correct. Fitted piston No 1.....perfect. Selected piston No2......top and 2nd ring on and came to the oil ring and......oh.....way too large.....
Strange, checked all the rings again and it would appear I have 1 spurious piston. The other 3 pistons (2,3,4) all have 2mm thickness rings however number 1 has a thicker oil ring (3mm) I can get the other rings swapped by my supplier but I'm inquisitive as to why this is. Possibly in its previous life it been rebuild with an oddy as I'd say or it rolled out the factory like this. My main concern is the now inserted piston No1 has a larger oil ring with larger holes in the ring than the other bores. Oil pressures etc be off as surley they should be equal. Does anyone know of which is correct for that engine or .....??? Any info would be great. Cheers.
