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Head P & P

Discussion in 'General Discussion' started by slow_yota, Feb 21, 2008.

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  1. slow_yota

    slow_yota Well-Known Member

    So i bought a kit from summitracing..a 70 piece port and polish kit..Loves it, but a machine shop guy told me today that i should only P & P the intake side of the head and not the exhaust ..Somthing about the head needing turbalence on the exiting of the gasses...True or False ?
     
    slow_yota, Feb 21, 2008
    #1
  2. slow_yota

    slow_yota Well-Known Member

    Never mind..Did some online research..I'll have some Pics sometime this weekend :)
     
    slow_yota, Feb 22, 2008
    #2
  3. Mafix

    Mafix Owner Staff Member Administrator Donated!

    the exit and combustion chamber can be smooth as glass. the intake ports need to be rough after the fuel injectors.
     
    Mafix, Feb 23, 2008
    #3
  4. slow_yota

    slow_yota Well-Known Member

    Rough intake porting is only needed for carbed engines, So the fuel doesnt pool up in the intake runners..F.I. engines dont have time to gather fuel.
     
    slow_yota, Feb 23, 2008
    #4
  5. slow_yota

    slow_yota Well-Known Member

    [​IMG]

    [​IMG]

    Intake side done..Just some minor porting/matching and polishing done
     
    slow_yota, Feb 23, 2008
    #5
  6. MITT4G

    MITT4G Well-Known Member

    That looks awesome !!
     
    MITT4G, Feb 23, 2008
    #6
  7. slow_yota

    slow_yota Well-Known Member

    lol..Thanks man..Im a noob but im doin my best
     
    slow_yota, Feb 23, 2008
    #7
  8. ST165-2765

    ST165-2765 Well-Known Member Donated!

    [​IMG] Dam I guess I'll have to start polishing the inside of things instead of the outside.

    Got a link for the kit from Summit?
     
    ST165-2765, Feb 23, 2008
    #8
  9. slow_yota

    slow_yota Well-Known Member

    http://store.summitracing.com/partdetai ... toview=sku

    yea gotta love the CNC look ;)


    I used an air dremmel..i gasket matched it, ground down the cast flashing with the stone head..then ran it over with the log wheel things and finished it off with the steel wool looking guys..the end result is a mirror shine and smooth as glass feel.i emailed Standard abrasives.They said if you do a port match, get the waviness smooth.. polish of the intake,exhaust sides of the head and then do the same to the header and intake runners on the manifold .You will see about a 8% gain in hp..maybe a lil more if you bore out the head a bit..But too much will hurt the low end.

    The bottom of my head is very clean but im gonna polish it a bit..here my before.

    [​IMG]

    Only thing they precautioned me about was staying clear of the stems and seats when using the stone head/wheels and to be sure and blow out and dump some brake cleaner it in the head before you mount it to the block.


    After will be done by the end of the weekend.
     
    slow_yota, Feb 23, 2008
    #9
  10. slow_yota

    slow_yota Well-Known Member

    Note to self..Using close up mode looks better :D
     
    slow_yota, Feb 23, 2008
    #10
  11. Klue

    Klue Well-Known Member Donated!

    see the divider between the two intake valves(for one cylinder) you should shape the air contacting edge so that it would create an even transition. Knife edging is the term. I would even try to shape that "hump" that seperates the two runners, you would have to do the same to the manifold aswell. EFI engines do need a rough textures intake manifold, the turbulence keeps the fuel molecules in circulation so that they do not condense. The effect is lessened on port injection engines. Like mafix said the exit should be as mirror like as possible to help keep the heat, and thus velocity of the exhaust gassers.
    Its probably a good idea to stay out of the combustion chamber if your new at this. but none the less check this out
    http://www.somender-singh.com/
    If you have the time, you should mirror polish the combustion chambers and cut down the sharp edges.
     
    Klue, Feb 23, 2008
    #11
  12. zak062

    zak062 Well-Known Member

    holy shit! how did u get ur head so clean!
     
    zak062, Feb 23, 2008
    #12
  13. slow_yota

    slow_yota Well-Known Member

    Klue...From what ive been told, And i got this info from a 20 year toyota tech that has built by himself a 800 hp supra..That FI engine do not need the rough surface..So..idk, im torn on this one

    On the that hump...it dont matter in the least bit..the tvis spacer goes over that..and unless i bore out the butterfly opening messing with that "hump" wont have any effect.

    I can post some pics if you want of the tvis spacer mounted if you dont understand.

    zak - i got it this clean from MITT, Think he said it was media blasted
     
    slow_yota, Feb 23, 2008
    #13
  14. Klue

    Klue Well-Known Member Donated!

    I understand the toyota variable inductions system perfectly. being a technician myself i would have to disagree with your friend with the 800 hp supra. I dont know if you mean forced induction or fuel injected but im going to assume the latter.

    Fuel injected engines are not the all the same, in your case a port fuel injection system has a dry manifold, so smoothing the manifold until it reaches the injectors should be ok. mind you that some fuel injection systems like TBI are basically pressurized carbs.

    I think that the biggest problem in the automotive industry and tuning in general is that people want answers instead of thinking things through. My theory using my basic understanding of fluid dynamics is that the turbulence created near the rough surfaces after the injectors keeps the fuel molecules(potentially water aswell) in a constant move so that they do not have time to condense.

    Ask your friend for an explanation, not an "answer"

    I was unaware you are keeping the TVIS. But i can assure you that the "hump" does matter, removing the hump helped run 13.2:1 compression on one of my ex 3sge's
     
    Klue, Feb 26, 2008
    #14
  15. Mafix

    Mafix Owner Staff Member Administrator Donated!

    klue is right on this. porting is fine but polishing after the injectors to the valves is not a good idea.
     
    Mafix, Feb 26, 2008
    #15
  16. slow_yota

    slow_yota Well-Known Member

    ok..the "hump" is something else, i thought you ment the little hump at the end of the chamber..Not the hump .that divides between the two valves..And yes TVIS does block that smaller hump and yes i'm def keeping it..This a n/a 11.5:1 comp motor..So i'm sure i'll still need it.

    And i asked for an explanation..What he said:


    "A cleaner smoother, port will let the fuel atomize faster and more efficientley, Rougher surfaces are only need in a carbed motor where the fuel to head route is a lot longer.judging from where your injectors sit.you wont notice any difference.the fuel is gonna be spraying on the back of the valve, so it wont matter what the runners/bowls are like.
    IMO and as short as the distance from injector to the valve is I cant see worrying about keeping fuel in suspension."
     
    slow_yota, Feb 26, 2008
    #16
  17. Mafix

    Mafix Owner Staff Member Administrator Donated!

    that is a valid point. i had not thought of it that way. do me a huge favor since your head is off:
    stick a straw in the injector hole and see where the fuel sprays and take a pic for me.

    btw love the sig!
     
    Mafix, Feb 27, 2008
    #17
  18. slow_yota

    slow_yota Well-Known Member

    I'll get a pic in a lil bit..

    Glad you like the sig..Not really for this site too much but
    [Well Rye doe throw a fit here and there but overall..All are cool here]
    ..More For one of the local sites im on..So TRUE !
     
    slow_yota, Feb 27, 2008
    #18
  19. slow_yota

    slow_yota Well-Known Member

    btw..Whats CAM2 ?
     
    slow_yota, Feb 27, 2008
    #19
  20. slow_yota

    slow_yota Well-Known Member

    I tried to set the "Princess Wand" as much to an angle as the injector sits..It looks like it could of been tilted a lil lower..But from the looks of it the fuel should barely hit the port entry at all.

    [​IMG]

    [​IMG]
     
    slow_yota, Feb 27, 2008
    #20
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