I dunno fellas. I’m going to have a good chat with Stephen and see where we go from here. Need to find the cause before rebuilding obviously. Thanks for everyones support by the way, it’s a little gay but I won’t hold it against any of you 
So Piston still attached and intact but exhaust values obviously had contact ?! Too much timing on the map ? is that even possible ? - again, sorry…just trying to learn here not speculate.
Anything is possible. Sadly suspect that the head of the valve has come away from the stem. Either poor quality, manufacturing problem - we have run these valves without issue on some of the Audi cars - map wrong, too many revs for the spec of the valve, springs too strong, valve float, loads of other reasons too, sadly.
Never ends well though 
OOF!
Stem semi seizing in the guide ?
Exhaust valves considerably hotter than inlet.
Additional lubrication up top maybe?
Used to add a cam wash sleeve on my old Opel engines to keep more oil up there as the top end was weak on them.
really sorry to see this JF 
My theory is that you used carbon fiber valves for the bling factor!
Cool, the piston still being attached is a good thing as this rules out a bottom end oiling issue and means your crank and most probably the rod, will have lived. Although I would change the rod as a precaution anyway.
Carbon rods it is then 
They lasted 10 minutes …
Hey, Jonny, the new fad with Honda’s engine builders is a small capacity 3 cylinder turbo engine. You’re nearly there Mate
PMSL lol
dry sump gotta be part of the next build?
Standard SC engine is the sensible choice.
Highly stressed, high revving atmo engines are great, apart from when you have the heart ache.
Track day cars are all about smiles per mile, surely. Just fit a 260bhp SC engine and get out there and enjoy yourself.
It’s staying NA but I’ll be speaking with Stephen and his engine builders next week. Need the block sleeved, new head, valves, springs, retainers and one rod. I know it’s sounds ignorant but I’d like to see this through.
Go SC.
Several air filters in line will mask the sound.
And never lift the engine cover! Job done!!! 
I’m going to stick up for NA, gives the car personality over a bought stock car
Honda JF?
Thank you Tim
Stick with it, Jonny
I think you should have another go too Jonny. We all like to do something a bit different (we own exiges is proof) so good on ya for taking a different tack.
Sean is right though, it’s no fun when it’s so fragile you can’t enjoy it. The last two times I’ve been looking forwards to being out on circuit at Donny with you, the car has broken. If I’d managed to make it last week that would have been three ina row. That’s no fun.