Been thinking about what you have said above.
So...... if I somehow managed to order an 89mm version of a standard piston and had the top left flat and tall, then got some heads with higher lift cams, with valves in place and then got a proper engine building engineering shop to cut the valve pockets carefully with the correct clearance then I would probably achieve what I wanted.
Is that what you are saying.
The question I have is how can the workshop be certain to obtain a CR that is say 12.0 to 1? If the crown is left tall, but the pockets need to be deep say, reducing the CR is there a chance that either the pockets could be deep enough to reduce the CR, or with the pockets cut there is still to much CR. I guess too much is easier to deal with than too little.
I would be concerned that if, with flat pistons and pockets cut, it does not make the desirable CR then I guess it means skimming the head, which then brings the valves nearer - which then means deepening the pockets - which then means shorter belts - which then means larger diameter cambelt tensioner wheels - and so it goes on.
Do you know if when building such an engine the heads are left pretty much as is (un-skimmed except for a cleaning cut), ignoring cams and valves, as this would make other factors more controllable.
Is someone like JE able to make an 89mm piston from a description and a further requirement to leave the head tall and unpocketed??
I did contact them and they asked me for spec sheets.....
I don't have such things.....