I have overhauled a 1098 cc engine (Morris). The listed compression ratio is 8,5:1. I have measured the cranking pressure and I get values of 11,5 bar
This seems very high to me.
Who has a clue as to what is wrong?

I used to play around with my cooper S years ago.

11.5 Bar is 167psi. This is not too high at all.
Just check to see if all cylinders produce the same gauge pressure.

Yeah my A series porduces 205psi per cylinder and factory is 185psi...its actually a bit low if anything....

All cylinders have the same pressure. When I stop the engine it keeps on "running" for a while like a diesel en can destroy the engine.
A solution could be that I change to petrol with a higher octane value.
We are currently checking is the right pistons were used.

Thamks for the answer

if it doesn't ping when driving, just stall it as you turn the key off.

if it is pinging, retard your ignition timing and/or try a colder plug.

having to buy premium fuels for a road car gets old real fast...