Thanks for sharing your experience @Twin Engine Corsa. One cause why they reversed the head, same as Honda did it on the H-series engines, was the better access to fresh air. It was shorter, not heated by the drivetrain system in the enginebay and could be done in a less restricting way. Performance-wise, this makes a huge difference. The former Swindon setup had a huge intake channel over the engine, over the header, which is way not optimal: it's long way on a heated channel, air has to turn into the bell mouths by a 180° turn causing losses and the hole channel thing is a restriction. Honda used the reverse head story also to lean back the engine for better weight distribution, the valvecover was almost touching on the firewall. All the 300+ engine setups of the FWD were kind of cool side front, hot side firewall, the other way around it is much more challenging.
Just picked up an old corsa b 1.2 which was my first car 15 years ago and I've wanted one for ages to be able to modify, might take 10 years to have the money to put into it but it's not going nowhere. Your channel has given me the kick I needed
With stroker 90mm crank and 88mm pistons running on methanol one drag car here put little over 360hp reverse head configuration all this back in 2004 , old Opel engines are amazing by the time!
I read somewhere that they did the reverse head for heat management in the engine bay and to have cold air ram into the intake, instead of sucking up hot air rising off of the exhaust as it passes under the engine... Not sure if that's accurate or true.
