Has this 885 head had 3 angle valve seats cut?

[14thirty]

Put my 885 head in to get new exhaust valve guides and 3 angle valve seats cut.

After picking it up I’ve found 3 of the intake valve sealing faces to be concave, and all the intake valve...

[14thirty]

ECU is a Megasquirt 2, I'll need to try and find somewhere to get it mapped properly once it's rebuilt. I'll look into a knock monitor.

If I don't stay with the stock cam, can I use an NA...

[14thirty]

I couldn't see any signs of detonation. I think the rings butted and broke the lands. Though timing won't have been great, never been on a dyno. It had the 9.7:1 pistons as well. Have some pictures here...

[14thirty]

My M20 turbo failed and I’m looking at options for the rebuild.
At minimum it needs a rebore and pistons due to ring land failure on #5 + #6, which has damaged the bores a bit.

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