VG33 heads on VG30 block


  • VG33 heads on VG30 block

    I have an 87 300ZX turbo (non W-series) and I plan to build the engine at some point next year.

    I know the early VG30 heads do not flow as well as the OWO heads (VG33 engine), especially on the exhaust side. I've learned that that the OWO heads will bolt up to the VG30et block (source RedZ31.com), but I do not know if there are any other changes I need to know about before I go down that path.

    Can someone point out issues with my current plan?

    - VG30et block (pre W-series)
    - VG33 heads (ported exhaust)
    - aftermarket VG30et cams
    - Adjustable VG30et cam gears
    - aftermarket valves & springs

    The VG33 heads have the 10mm exhaust studs, so will the stock VG30 manifolds fit with modification?

    Is there anything else I need to know?

    Thanks!
    1988 300ZX Turbo Shiro Special

  • #2
    You can run the round tooth gears if you source a round tooth crank gear. You should anyway if you are going through the engine like this, IMO. Everything looks good the only thing I see missing are MLS head gaskets to keep that sucker sealed and maybe pair them with ARP head studs for extra insurance! lol!

    Anyway, welcome to the site!
    "Its the s12's sexy over weight step daughter, the z31"

  • #3
    I'm putting the VG33 heads on my A/B series 86NA block. So, to answer…

    Originally posted by HarvesterUT View Post
    Can someone point out issues with my current plan? All of the below looks good, I'm doing the same

    - VG30et block (pre W-series)
    - VG33 heads (ported exhaust)
    - aftermarket VG30et cams
    - Adjustable VG30et cam gears
    - aftermarket valves & springs


    The VG33 heads have the 10mm exhaust studs, so will the stock VG30 manifolds fit with modification? Yes, you just have to drill out the holes for the studs on the manifolds a little.

    Is there anything else I need to know? Not that I can think of. Just make sure you use the headgasket that goes with your engine, and not the one that would apply to what the heads came out of.

    Thanks!
    Prius… because Pretentious wouldn't fit across the back of the car…

    Cheap, Fast, Reliable - pick any two

    My 1986 Turbo Build

  • #4
    Hey guys,

    Thanks for the advice! I'll definitely do the ARP bolts and MLS gaskets. Seems like cheap insurance. I didn't think about swapping over to round-tooth belts. Is there any benefit to round-tooth over square beyond longevity?
    1988 300ZX Turbo Shiro Special

  • #5
    They make a Goodyear Racing timing belt, that is the color blue, that fits the square tooth cam gears. To me that looks sharp when the timing cover is removed
    shotyme

  • #6
    It's not goodyear, it's Gates Racing.
    Prius… because Pretentious wouldn't fit across the back of the car…

    Cheap, Fast, Reliable - pick any two

    My 1986 Turbo Build

  • #7
    The gates racing belt is stronger. The expensive version is actually kevlar reinforced
    Usual Z31 suspect: Garage Queen (aka broken)

  • #8
    1994 Maxima crank gear is what I'm running on my A/B Series VG with VG33 round tooth cam sprockets.
    http://www.courtesyparts.com/13021-s…611_1612_1620&
    Cha iro

    enjoy building it yourself.
    if it fails, fuck it.
    at least you gave it a whirl.

  • #9
    Just thought I'd update that my install was successful. Car started and ran on Sunday night. 1986 A/B series NA engine with OWO heads and Isky cams, using A/B series head gasket.
    Prius… because Pretentious wouldn't fit across the back of the car…

    Cheap, Fast, Reliable - pick any two

    My 1986 Turbo Build

  • #10
    Originally posted by jaqattack02 View Post
    It's not goodyear, it's Gates Racing.
    My bad.., not sure why I mention Goodyear
    shotyme

  • #11
    Here's the engine semi-assembled with the fancy blue belt.

    Prius… because Pretentious wouldn't fit across the back of the car…

    Cheap, Fast, Reliable - pick any two

    My 1986 Turbo Build

  • #12
    jaqattack02 - It's hard to tell from the photo, but I assume that's a square-tooth timing belt and Russ' adjustable cam gears?
    1988 300ZX Turbo Shiro Special

  • #13
    Did the injector and air ports line up correctly with the Lim to head?
    Usual Z31 suspect: Garage Queen (aka broken)

  • #14
    Yea that's a square tooth set up with Russ's gears. They only make the gates racing belt with square teeth.

  • #15
    Originally posted by 300zxturboftw
    Did the injector and air ports line up correctly with the Lim to head?
    Plz answer this jaqattack! Did you use vg 33 LIM or 30 LIM? I want to get mine squared off before I tune.
    Usual Z31 suspect: Garage Queen (aka broken)