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new build with some questions

Discussion in 'Engine Building' started by Magana559, Aug 27, 2013.

  1. Magana559

    Magana559 The Warden

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    I have a p75 head that was ported and polished by JG engine dynamics with oversized 31.5 millimeter intake valve and 28 .5 exhaust valves. So my question is I'm going to have to replace the valve guides on this head and might have to replace the valve seat. So if I have to replace the valve seats can I replace the valve seats with the valve seats of a p8r b20 head that uses 33mm intake valves on my p75 head?

    Also will this affect the port flow in a bad way if i was to change the valve size?

    Engine is going to be a 82mm 13:1 comp with my full built ported ls head with forged pistons and rods running on e85 with crower 405 cams.
     
  2. Magana559

    Magana559 The Warden

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    Maybe nitrous.
     
  3. phunky.buddha

    phunky.buddha Admin with a big stick Admin VIP

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    Hmm not sure- maybe you have to weld in the seats a little? Possibly too large for your valves? Or just go to 33mm valves?
     
  4. Magana559

    Magana559 The Warden

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    Thats what I'm trying to do. I want to know if p8r valve seats (33mm) will fit in a p75 LS head. If they can I can do 33mm valves (same size as VTEC)
     
  5. Magana559

    Magana559 The Warden

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    33mm valves for a p8r head that is.
     
  6. Magana559

    Magana559 The Warden

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    Anybody know the OEM # for p8r intake valves? And valve seats #
     
  7. Magana559

    Magana559 The Warden

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    14711-PH3-000 as close as I can get but this one is 104.4 ol and LS valve is 105.5 ol.

    I'll give a valve place a call see if they can stretch one for me (custom valve).
     
  8. phunky.buddha

    phunky.buddha Admin with a big stick Admin VIP

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    Do you just want an actual P8R head? I'm pretty sure we have one at the shop...
     
  9. Magana559

    Magana559 The Warden

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    No I have a jg P&P head with 31.5mm intake valves. The p8r has 33mm intake valves (same size as VTEC head) so I was wondering what if I dropped some p8r valve seats and valves in a p75 head would I gain flow and velocity?

    I would also want to know if the p8r and and the p75 use the same valve diameter and same valve length.
     
  10. Magana559

    Magana559 The Warden

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    Also according to sivalves.com the prelude 2.0 has the 33mm intake valve same ol length and same valve steam diameter of 6.6.

    I need a spec sheet to see if they are interchangeable.
     
  11. phunky.buddha

    phunky.buddha Admin with a big stick Admin VIP

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    Ask some head porters? I'm sure they've been asked to fit large valves into heads- I don't think they'd refuse to tell you if it could be done since they'd stand to gain your business if you ended up thinking it was too difficult to do yourself. ;)
     
  12. Magana559

    Magana559 The Warden

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    Problem is the best guy in town is a older guy and hasn't been seen in a while and he did awesome porting and polishing and had his own flow bench.
     
  13. Magana559

    Magana559 The Warden

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    I just don't want to spend money I don't have to.
     
  14. phunky.buddha

    phunky.buddha Admin with a big stick Admin VIP

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    Oh I hear ya, wasting money is never fun.
     
  15. Magana559

    Magana559 The Warden

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    Close this thread project abandoned, too much money and nobody wants to try it unless the head is stock. Uhhh I'm done I'll just stick with 31.5mm valves.
     
  16. phunky.buddha

    phunky.buddha Admin with a big stick Admin VIP

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    :( Did you talk to the shops?
     
  17. CAFROG

    CAFROG Honda Minion VIP

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    God forbid these shops mic stuff up and make something work. They don't know who JG is and are probably worried what exist and how it might make them to blame if it don't last.
     
  18. Magana559

    Magana559 The Warden

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    [OTE=Calesta;17]:( Did you talk to the shops?[/QUOTE]



    Dude it was like talking to monkeys or special ed machinist......"uuuuuuhhhh if the head flows why do you want to mess with it" because i want more flow you idiot!

    "Im not going to take a chance destroying your head, if you want, bring in a stock head and we can try it" if I want to take the risk let's do it! lets try to give these guys with ls heads a chance to make the head flow better without going vtec.
     
  19. Magana559

    Magana559 The Warden

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    All three guys noticed the three jg stamp and said " that's a great head because it was done when good jg was great" when jg went bad it was a hit after they started stamping JGE
     
  20. Magana559

    Magana559 The Warden

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    So game over guys time to start the re re high comp LS head thread
     
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