Example of Low Quality Aftermarket Spare Part

Here's a couple of examples of low quality aftermarket cylinder blocks. Aparently the bimetallization stage of the barrel manufacturing process is more complicated than one might figure. This type of failure is relatively common for cheap Chinese-made barrels - the brass layer detaches during the first hour/minute of normal operation at pressures often lower than nominal, the barrels normally present no external deficiencies before the failure.

I once saw a series 90 aftermartket cylinder block detach the brass at 300 bar during the first 30 seconds of the first test run.