Compression Ratio and Head Porting Question
Hi all, I hope with a little guidance I can start to make further progress with my 2012 super Twin build.
Ok so it's seemingly impossible to simply ask racers (that I won't be competing against) for the details of how much they milled off of their heads, I can understand wanting to keep trade secrets when it comes to head porting, and prototype work, but a simple figure to mill of the head..... lol
Anyway, I'll buy some fluid measuring equipment, and calculate the last few factors required to calculate my own CR, question is.... What CR would accept E20 (98-99Ron) fuel, alternatively I can run straight 95Ron benzine, both of which are available at all Thai fuel stations.
As it stands, I'm thinking of calculating how much to mill off the head and aiming for 12.5:1, this should be safe(ish) (correct me if wrong), and later I could bump the CR a little higher if needed buy either milling the head further or removing the middle section of the head gasket.
I assume (prior to measuring) that the removal of the middle section of the head gasket would add 0.3:1 - 0.4:1.
Again, thanks for any advice and sorry if I seem to be 'prying information'
I'm thinking of removing the hump (photo attached) on the floor and roof of the throat up until about and inch before the divider of each intake port, which will effectively enlarge the rubber throttlebody mounts and entrance of the throats, then tapering off and inch before the dividers.
The rest of the port job is just basic valve seat matching, removing of flashings, knife edging dividers, 80 grit finish on the intake and 400 grit on the exhaust.
A little approval or disapproval towards removing the humps in the throats (pic attached) would help me finish my porting job
All this work will be complemented with the Versys cam mod (which I still need to look into a little more), Polished and smoothed combustion chambers and also stock pistons, Arrow headers, Custom longer mid and tail pipe, PCV with ignition adjustment, DNA filter, Modified Airbox and around 12.5:1CR. Bottom end has been blue printed