B16a cylinderhead development pt.5

Bigger now to show details of the exhaust port

and the lighting and shadows help visually
in showing the overal shape achieved

-notice the port's curve from valveseat to throat all the way to the exit
 the attempt is to shape it to achieve a gradual of a bend as possible
 without needing too much material removal , we avoid hogging out the ports

- the lighting shows this (roof section of the port) and the shadows  help
  visualize the blending on the splitter and short turn radius

next pic showing much of the same, but with more visible details

shadow and lighting doing its part in showing the overall port curve/bend and smoothness

- notice the casting marks on the throat (splitter side) still a little bit visible
  hogging it out isnt needed  unless you dislike torque :)
  even on the port exit at the outer perimeter the casting flash is a bit visible 

- notice at the base of the splitter (top of the splitter in the pic) some of the
  tiny dots are casting bubbles , no need to totally remove them
  as the only benefit we can get from that is cosmetic in nature
  and port volume increase isnt really needed here
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this cylinderhead was done for a client
who has a simple build that is a b16a (1600cc)
on a 4door EK variant sedan

with these heads + decent cams and a good exhaust
it has run well into the 13second range in the 1/4mile
and thats with just a 1600cc displacement

B16a cylinderhead development pt.4

exhaust ports now for the b16 head
*this is exhaust port 1  (above)

the lighting shows the shape and contouring done to aid in flow exit
without increasing port volume too much that it lessens exhaust exit speed

overall , if the port exit speed is high enough, the engine has to work less to
rid itself of the exhaust fumes and spent gasses
which in turn could let us run a bigger cam or tweak on overlap
without as much drawback to it

-interesting tid bit , most honda cylinder heads has exhaust ports that are directional
 meaning none of them are of the same exit angle (left to right) from one another

- this pic is of exhaust port 1 (cylinder number 1)

*exhaust port 2 (above)

-notice the direction compare to exh port 1 , its angled to the same side
 but to a lesser degree

-very basic detail showing flow improvements done by way of
 proper shaping and contouring of the ports

*exhaust port 3 (above)

-now we see a directional change from left facing to right facing angle
 compare to exhaust port 2 for reference

- the guideboss in the exhaust port arent as obstructing as the intake ports
  so minimal shaping or material removal is needed , plus the flow now is in reverse
  compare to the intake guide boss , think of an aerofoil for reference

*exhaust port 4 (above)

-direction of the port is a lil more pronounced compare to exh port 3
 basically the number 4 port is now a mirror image of exh port 1 in reverse

-some people port the exhaust and try to reshape them in ways that
 they try to make all 4 ports angle to the same direction (straight)
 and it is possible , it also looks good
 unfortunately that is all that is good to it.. looking good
 as flow then vary from 1 exhaust port to another  ultimately making it inefficient

-port texture on the exhaust port is in some ways a lil different to texturing the intake
 for one , the critical importance of keeping fuel atomized is gone
 another , sooner or later the portwalls are coverd in carbon deposits

-making sure theres a uniform finish to the exhaust port is better
 smoothing it is ok... so long as it is uniform , so that carbon deposits  would stick
 evenly  ...we dont want sections with carbon and other sections clean 
 it only then means the shape has lost its benefit

so again... the term PORT AND POLISH
is quite a misnomer , since   we havnt and dont ever "polish" anything
as far as texturing goes

B16a cylinderhead development pt.3

a shot of the ports, viewing from the chamber side

the lighting indeed helps to show the texture of the port surface
for better fuel atomization

and how it changes in texture as it reaches the throat and to the seat

-in theory this is to speed up flow as it reaches the valve
 with attempts at generating more possible flow and intake charge
 into the combustion chamber

- the section between guide boss and splitter is noticeable here
  with regards to work done to minimize obstruction in flow

- guide boss itself is seen here having more "aerodynamic" profile/shape

another shot from the chamber viewing the intake ports

- here, a more visible guide boss  shaped with a more aerodynamic profile
  some chop it all off, some shorten it ,  but by shaping it this way
  you minimize volume increase and actually maintain a higher flowspeed

- notice the texture change of the port leading to the throat
  and the throat being concentric to the valve seat

another shot from the chamber side, this time showing both valve entry

- this was taken bfor being totally finished  as evidenced by the texture change
   but also best illustrates the work done to it,

- the keen eye may notice , the port itself is still pretty "mild" as far as port enlarging
  and or sizing goes ,
  but funny enough this head will promote good intake flow velocity
  thats good for making decent torque 

- this head could work on smaller displacements and do wonders with regards to
  torque and power production
  and still be able to work with larger displacements , with just changes in
  camshaft profile to match 

B16a cylinderhead development pt.2

with better lighting , to show more details on the portwork

- the "top" of the splitter (the portion in between te guide boss in the picture)
  you can see its shaped nicely , to guide flow into each sides
  without hogging it all out and increasing unnecessary volume

- the outer walls of the port depicts a better visual on how "gradual" the short turn
  as been made and slightly widened 

- all the work done , leads to guiding flow into the port "throat" which then
  guides and prepares flow to go around the valve seat

B16a cylinderhead development

intake shot of the ports 
worked the critical areas and textured the surface once shape is achieved

-guide boss shaped as to minimize obstruction in flow
-notice the contours/shapee leading into the port "throat"
 which then leads to the seat section , critical flow is gained and achieved here
 when done correctly

here's a better angle/picture to show the intake port work and all

-notice the outside walls (outer section of the port) and its shape gently
 bending towards the throat bigger is never better

-guide boss shaped visibly , and total removal of such would cause
 premature guide wear and loss of stability in high rpm's

-critical area such as the "splitter"  short side of the splitter and top (between guides)
 are carefully worked on , and contoured to guide flow into the throat of the port

F22a Non Vtec Cyl.Head pt.4

Above is the intake side shot of the Head all done and prepped for assembly
:)

here's the exhaust end of the business :)
just minor clean up done to it (casting flash still visible)
and made it more flow friendly as far as shape and contouring goes

a picture of some of the valves to show the 45degree sealing face at the back
have been refaced  to ensure "trueness" for superior sealing when valve is closed

-its been lightly lapped  to show and check the section it rides the sealing face

-notice its on the outer perimeter of the 45deg. face  this is desired as it gives the notion
 of a slightly bigger valve , as far as flow is concerned around the valveseat area

F22a Non Vtec Cyl.Head pt.3

a pair of pictures , showing some detail on the chambers

with a more intricate view of the 3 angle valvejob done to it
some trick work done to this to achieve a biased quench depth

standard valvejobs we have the following specifications
-1mm intake seat width and 1.25mm exhaust seat width
-0.85mm intake seat width and 1mm exhaust seat width
- a narrower 0.75mm intake seat width
/-this is all pertaining to the width of the 45degree seat (1 of the 3 angles in a VJ)

we also have a high performance oriented valve job 
that is specific to "intake" and "exhaust" as far as angles go
and they're multi-angle + radius top cut  for even more flow

F22a Non Vtec Cyl.Head pt.2

a picture of the chamber , viewing the exhaust port (above)

a regular valvejob (3 angle seat cut) is done here
with the intakes having a 1mm / 0.040" wide seat
and exhaust having  1.25/0.060" wide seat

second picture of the chamber , viewing the intake port (above)

F22a Non Vtec Cyl.Head

here's a shot of the intake port layout (above) 
ported and shaped, and the finish texture achieved
-notice the port is quite "tall"  in a sense that is a more straight shot
 interestingly, the Kseries variant is very similar

next shot shows a better view of the texture (above)
ideally we dont want it ultra smooth hence the term port and "polish"
is sort of a misnomer, 
having too smooth of a surface, tends to minimize "atomization"
of liquid fuel and air... 
notice the change in texture at the "throat" which is also an attempt in
"speeding" up flow as it reaches the seat of the valve

-on the other hand, this picture shows the f22a non vtec head's taller lay out
 of the intake port, it also has a more vertical valve axis/angle
 which gives it a more "straight shot" into the chamber