Well - there is a worldwide pandemic occurring, the west coast of the United States is on fire, we have a contested election - that hasn't even occurred yet - and none of us can agree on any facts.
This kind of cylinder with the maxed out bridge port is a good point of reference. Won't all work for yours but some of the ideas are transferable. When the time comes we can do the detail.
And yet - within our group of misfits - we know that 1mm of exhaust port lift = about 1HP of output and raises the power band. How I love this forum.
In that spirit - and because I like causing Jack's angina to flare - I give you this:
It is popular in piston ported motor bicycling.
If you don't know what that is - its that really loud bicycle with a two stroke strapped to it - pouring soot at the tail pipe - that passed you at lunch the other day.
Think less refined vespa meets steam punk.
Rather than try and grind the roof of the transfers to lift them - these guys grind the top of the piston to lower it.
The net effect is to lift port timing- tho I imagine it doesn't do wonders for your squish band.
But then - they are not all about refinement.
They do it on the exhaust ports and transfers.
The interesting part to me was - this could allow some adjustment of transfer height to lower Blow Down timing - without having to try and grind transfer port roofs - something none of us really do.
It is also lower risk - a new piston is $80 - not $450 like a cylinder.
I post it in the spirit of the MHR cylinder project - and the previously noted Jack's angina.
My challenge on the MHR: If we were to create two paths - one to optimize grunt, and one to optimize peak HP - what would be the different exhaust port shapes we would go after - and what other tuning would we combine?
This is a fairly common practice for motor bicycles - they adjust both transfer and exhaust port timing by altering the piston top
In situ - example of exhaust port "lifting" by lowering of the piston.