Dont know whether this should be on a technical thread.
Firstly to briefly explain my situation, i drive a 07 S3 with BZC engine code and i have revo stage 2+ on the car for approximately 6 months now, back in september one of my pistons got damaged by unknown causes and this prompted me to replace all four s3 pistons with Golf 5 GTI AXX motor pistons , reason being that i could not source one s3 piston to replace the damaged one. In order to do this I had to replace the RODS with IE forged rods since the gti pistons could not link to the S3 stock rods. this job was done and now about 3 weeks ago i started picking up a vibration on clutch pedal, so not knowing what the problem was, took it to another mech who then now a week ago diagnosed the crank as being damaged aswell as bits of the block itself due to thrust washers falling off and crank having excessive play on it due to this.
Now i have to basically find another bottom end for my engine, and all of the people i have phoned thus far that i know of in South Africa have nothing for the S3 BZC engine. My mech suggested that if i couldnt find BZC block i should consider using a AXX or BWA block from the golf 5 GTI as these are more common round here.
What i wanna know is how safe is this, the only thing according to spec thats different between BZC, AXX and BWA is the compression ratio, other than that the block, bottom end is pretty much the same. If anyone has had a similar experience please let me know , thanks