NISMO heads for the VG30E/ET

  • a22770
    a22770
    Senior Member
    • 207

    #61
    Will try to make a short movie tomorrow, showing the differences in the heads. Here is a short list.
    intake port trajectory is like a honda cbr 600.
    exh port is like an 18 degree chevy, but with some turn to it.
    intake floor at entrance is 2.7" off the deck, stock is .800"
    exh exit is 1.6" off the deck, stock is .700"
    valve angles are 22 and 22, 44 included. stock is 25 and 25, 50 included.
    cam bore is .600" higher off the deck than stock (guess stock T. belt is out)
    chamber is slightly shallower
    no coolant alongside intake runner
    Spring pads are much larger, 1.650". stock 1.450"
  • Careless
    Careless
    Senior Member
    • 13279

    #62
    speccing a belt is easy if you have the cam gears and the total length.
    i can help with that if you have total measurements using a length of string
  • ZFast88Z
    ZFast88Z
    Senior Member
    • 1882

    #63
    The main girdle was designed to minimize flexing up the block during extended periods of high rpm use.

    Wonder what it would cost to recast a couple sets of heads since you already have a pattern to start out with.
    The bullshit stops, when the GREEN light drops.

    Only babies cry about the bottle.
  • hoov100
    hoov100
    Senior Member
    • 148

    #64
    ZFast88Z wrote: The main girdle was designed to minimize flexing up the block during extended periods of high rpm use.

    Wonder what it would cost to recast a couple sets of heads since you already have a pattern to start out with.
    In other words nissan was cheap and didn't want to go with 4 bolt main caps to actually fix the problem.
    shooting for power, but coming up short.
  • Careless
    Careless
    Senior Member
    • 13279

    #65
    [quote]hoov100 wrote:
    Originally posted by ZFast88Z
    The main girdle was designed to minimize flexing up the block during extended periods of high rpm use.

    Wonder what it would cost to recast a couple sets of heads since you already have a pattern to start out with.
    In other words nissan was cheap and didn't want to go with 4 bolt main caps to actually fix the problem.
    what? they made the pan rail way thicker and the main girdle was pretty much integrated into the pan rail, almost like a two-piece block. How is that not solving the problem when they produced 1000hp+ for countless hours at full song?
  • hoov100
    hoov100
    Senior Member
    • 148

    #66
    [quote]Careless wrote: [quote=hoov100]
    Originally posted by ZFast88Z
    The main girdle was designed to minimize flexing up the block during extended periods of high rpm use.

    Wonder what it would cost to recast a couple sets of heads since you already have a pattern to start out with.
    In other words nissan was cheap and didn't want to go with 4 bolt main caps to actually fix the problem.
    what? they made the pan rail way thicker and the main girdle was pretty much integrated into the pan rail, almost like a two-piece block. How is that not solving the problem when they produced 1000hp+ for countless hours at full song?
    Thought he was talking about the stock girdle? :-? You know damn well I wouldn't diss that girdle of death electramotive made for the race cars.

    And sadly, after all the parts still available nobody can seems to find one of the hundred of those girdles they made.
    shooting for power, but coming up short.
  • ZFast88Z
    ZFast88Z
    Senior Member
    • 1882

    #67
    I know where 5 of the girdles are along with a number of the GTP car parts. They are in Ohio. The owner will not split the lot up and wants $60,000 for the collection. He has numerous spare engine assemblies, and parts to build a couple more. Believe he also has the transmission/transaxle and some other components.

    The stock girdle with 2 bolts per main cap does a far better job of preventing block flexing then a 4 bolt main system would. Even if you used a splayed 4 bolt main caps, the girdle would still perform the job better.

    Back on topic, heads sound sexified for 10,000RPM short stroke VG
    The bullshit stops, when the GREEN light drops.

    Only babies cry about the bottle.
  • nismopu
    nismopu
    Administrator
    • 2221

    #68
    Question. Since the heads have everything raised so much does that make them physically taller as well? Also, were they even using lifters or short pushrods/solid lifter pieces like was rumored? Is the cam bore the same diameter or did they increase it? I really cant wait to see what comes of these, I am glad they fell into competent hands!!
    "Its the s12's sexy over weight step daughter, the z31"
  • hoov100
    hoov100
    Senior Member
    • 148

    #69
    I think we need pics of the valves and springs… :-D
    shooting for power, but coming up short.
  • a22770
    a22770
    Senior Member
    • 207

    #70
    Here is the video. Spring in the video is stock diameter. Yes the head is taller, cam bore is raised and diameter is stock. Has inserts ( cup ) to repl lifter internals and a pushrod that is about 1.5" long and cup adjuster in the jesel rockers.

    http://www.youtube.com/watch?v=YV4fyzMJ9Sw[/video]]
  • NissanEgg
    NissanEgg
    Senior Member
    • 5220

    #71
    I should get a cookie for posting this for you to spend mucho dinero.

    1986 300ZX Turbo…sold
    1990 Skyline GT-R…new money pit
    2014 Juke Nismo RS 6-speed…daily
  • hoov100
    hoov100
    Senior Member
    • 148

    #72
    NissanEgg wrote: I should get a cookie for posting this for you to spend mucho dinero.
    These heads are bitchin and really aren't that expensive when you compare them to having a custom head built for something else.

    And yes, I just came… :lol:
    shooting for power, but coming up short.
  • a22770
    a22770
    Senior Member
    • 207

    #73
    Pretty sure it will take $8k to get them running. Everything must be right, nobody makes it, and therefore must be custom fabricated.
    Looking at seat materials for Ti valves today.
  • ZFast88Z
    ZFast88Z
    Senior Member
    • 1882

    #74
    Custom copper beryllium valve seats…I shudder at that expense!

    I was going to say 6-7K for completed heads considering you are doing all the port work and development yourself. I can only imagine how much more they would be if you had to pay someone for the port work.
    The bullshit stops, when the GREEN light drops.

    Only babies cry about the bottle.
  • Careless
    Careless
    Senior Member
    • 13279

    #75
    Someone should make berry ring valve seats that are close enough to the size you need that will allow you to machine them to fit down to the size you want, no?

    Someone also posted a crazy huge valve catalog on hybridz when I was looking for RB26 valves. I found a buick valve that could just be cut and have the lock groove turned back onto the stem on a lathe, and it would have been a perfect fit.

    They were titanium too!