Xu51c and xu5ja piston differences?

[Gsxrmick1984 10]

Hi. I have a xu51c 1.6 carb model which I am wanting to get a bit more power from. I have a 1.6 GTI head which I was going to fit and some better carbs. I thought the block was the same but apparently the pistons are different. Anyone know what the difference is? Is it a big enough difference that I'd be better sourcing some GTI pistons? 

 

Thanks 

[DamirGTI 342]

XU5C has different piston crown .. not the "moon shape" dish as on the XU5JA

 

Overall piston height is same , as well as the compression height .. it's just the crown/dish shape and depth difference .. with the XU5C having deeper dish (or flat , so without the dish) ..

 

Not so sure , as it was long time ago since i've seen XU5C head , but if i remember the head combustion chambers are also different on XU5C .. so , same round shape as the piston crowns without "moon shape" squish area ...

 

D

Edited December 27, 2019 by DamirGTI

[Gsxrmick1984 10]

Thanks for the info. I've been looking around and found this picture of a 205 with the same engine code with the head removed. It was in french but the pistons look similar to the gti pistons with the dish and not flat. I suppose it's probably a deeper dish like you say. I already have the head  so might fit it and see what happens. Don't suppose it can be worse with a gti head