MA10ET motor info - figaro myths?

After blowing up my fig motor I wanted to fix it - since one head stud broke inside the old block I had to source an MA10 block. I got luck and got a full shortblock from a K10.

We opened up the engine and what a surprise - all internals in the MA10 are the same as in MA10ET! I was mostly shocked by the pistons - as all the respectable workshops dealing with those cars argue that micra pistons are different compression ratio. From our measurements, the pistons are exactly the same, whats more it seems that they also fit the k11!

Any opinions welcome!


The part numbers for e.g pistons are definitely different. The measurements seem OK. Maybe it's the material tof he OEM MA10ET pistons, that differes from MA10? Anybody has any advice or experience in this domain?
Yes, indeed frank. I think the ones we got here were the lower compression ones due to fuel quality those days. Still, it looks like all botom end is exactly the same (MA10et and MA10). If anybody knows if materials were different, or what could be the difference in oem part numbers I would be much obliged :)

I understand that in the case that the fig pistons and nd micra ones are the same, crank is the same, then the main difference has to be the head (+gasket?), having a low compression ratio of 8.0:1.

This is very curious, I know stock pistons can take some heat, as I used ot have a micra with nitrous - all stock internals. This could mean tht the factory used same grade pistons as they know they would take this extra power..?
I start to belive that the main difference between MA10 and MA10ET in terms of internals is that pistons in N/A engine hve lower tolerances (meaning std. piston marked). MA10ET, being "high performance" probably has closer tolerances, thus different piston grades...