f23 hybrid motor theoretical build notes

F23 block:
-86mm bore – bore out to 87mm
-219.5mm deck height
K24 crank:
-99mm stroke – offset grind to 102mm stroke
-51mm rod journals – offset grind down to 48mm
K20 rods:
-22mm pins
-51mm mains -custom rods with 48mm mains
k24 pistons:
22mm pins
87mm bore
30mm comp height
0cc dome

End result should be 2425cc motor with a piston that protrudes from the block .5mm.. so need a .5mm thick headgasket for zero piston to head clearance  .5mm is .0197 inches, lets round to .020 to correlate to imperial units. Oem 3 layer gasket is .026mm thick.  This gives .006 inches clearance.. not enough.. but adjusting the offset griding operaiton on the crank should easily get us a tiny but less stroke and the exact quench we want.  What that is I do not know.. the v8 guys discuss this in detail but I have not found the honda knowledge base on this yet.  I suspect it to be about .030 inchs = .75mm resulting in a 101.3mm stroke and a tiny bit less displacement. 2408cc 12.3:1 compression.  I think there is still too much custom machine work and not enough off the shelf parts for this build, but if it looks interesting to you, have fun.  You can use the h22 DOHC head instead of f23 head and should get you 240+ whp with right around 200 ft/lb at the wheels.



Zend_Form only displaying the last Zend_Element

I had to wrestle with this for a while until I figured it out.  I was not validating the input to the ordering of the elements well enough.. IE I had a null being passed in like
$element->setOrder($invalidValueFromDb);  // very simplified but you get the gist

So lesson learned, Zend_Form is quite happy to accept a null for an ordering value, generating no warning or errors, and only rendering the very last Zend_Element in a fully populated array of elements.

Solution, check that you have an intval, if not, don’t set the order at all, leave it alone.

k23a1 RDX turbo connecting rods and pistons

Note to see so I can find this later.
small end 22mm
big end 51mm
inner edge to inner edge 113mm
math and stuff = 149.5mm long rod..  a k20 is 139 and a k24 is 152. did I screw up by 2.5mm or is the k23 rod a one off weird length?

F23a4 rod is 139mm and compression height is 30mm

k23a piston pin to top of piston is 20.15mm
dish holds 3 teaspoons water, about 15 cc, so -15cc dome
Using this calculator, with f23 motor + k23 rod + piston gets an 8:1 motor with hopefully better rods and pistons. Unless of course my measurements are screwed up somehow…
Will find out when I take the spare f23a4 apart and compare.  Might have a junkyard special on my hands 🙂

UPDATE: compression height IS half of the small end + the distance from pin edge to piston top. Compression height of the k23 piston is 31mm.

I need to post some pics here.. the ringlands on these things make me happy.