Nope, HF was pre-vtec. It was a SOHC 8-valve job too.
When I bought my HF it had a cracked valve at 75k (about 1/4 of the valve face was gone
) makes me wonder about the detonation thing...
And I can't help but wonder if a little low rpm detonation would be too much for an engine to cope with. They've all got knock sensors now, so the ECU just dials back the timing, and you've got a little less power to take off with.
I think the Honda D-series (B's to a lesser extent) may be good candidates, they're all undersquare, so good for torque. They have cheap parts, so easy to get the custom grind and bump up compression. And they have all of the electronics that you'd need. Plus, they're cheap and plentiful, so you could easily replace it if you broke anything
Oh, and the way I understood it, the Atkinson gets its efficency from retaining more of its kinetic energy from the compression stroke since it is compressing less volume than an Otto cycle engine. Sure the nomenclature remains (compression ratios) but the meaning is changes when you're not actually compressing 30% of that volume.