cylinder head porting
I "think" I know something about porting and CC'ing and have personally done some on a SBC. But I do know that Im not qualified to do zx12r head so Im looking for a place. I would CC my 12r head to know where its starting but no grinding.
The West Coast of Canada has little to offer. The US has some, but most have moved on to other bikes. I would think a canned CNC porting job could be found, id be shipping it so where in US doesn't really matter, I am going to Glasgow for a month soon so I could take it with me if there was a well recommended place.
I have a fresh 1287 with 13:1 JE's, kent kaw23 (9.88@260, 9.37@258) 108lc cams, adj sprockets, bear short stacks, akra pipe, advanced timing, PC5 w. O2 sensor. Stock rods/crank with 25K on them. Billet clutch and undercut trans.
I have not yet flashed ecu for speed, timing, rpm extend (maybe better rods/bolts 1st) and a new oil pump.
So its winter and while its apart, I was looking for appropriate porting to augment the +3mm of the 1287 including gasket matching, bowl blending, and un-shrouding of valves in CC, upgraded springs but not really high pressure.
One place I talked to says they don't enlarge the CC due to the loss of CR, but Im already up .8 with the piston change!
2nd place said stage II $2500 comes with their supplied cams, I want to use the cams I have already obtained which I believe to be reasonable for my build.
I assume JE 13:1 is with stock chambers which are what volume with oe HG? I plan to measure and adj. squish with the base gasket and thin HG or surface head to restore CR.
For those that have done this more than once... How much increase in CC volume to properly un-shroud intake valves, or what should be done? What is a reasonable squish target 0.035? PtH clearance? PtV clearance target value?
Who to use, do I have to specify and they work to spec or do they not like being told, and they know zx12r best?
Prices range $1000 - 2500 and probably more for add-ons like springs, seals, ti, seats, oversize valves etc etc. What should I be paying for what I need? Stick with CNC porting or do they just rough it with CNC and finish by hand anyways?
Goal: Drive to work, scare me when I want it too, drag it to see what it/I will do, some LSR runs would be fun, track days. Im not looking for the ragged edge - I gave up on the stroker plan for this build.
Last edited by weedy64; 11-29-2016 at 11:37 AM.