boring a vg30 out to vg33 will Not work

  • SATAN
    SATAN
    Senior Member
    • 6782

    #46
    ZFast88Z wrote: So I do the math myself, and have determined the calculator must be wrong. I get the same answer as you do.
    Ok good LOL. I had to double check myself to make sure. :lol:
    85 Z31 6.0 LSX turbo 766whp/792wtq
    04 GTO, LS6, big cam, porting, N20… underway for summertime daily driver.
  • ZFast88Z
    ZFast88Z
    Senior Member
    • 1882

    #47
    [quote]SATAN wrote:
    Originally posted by ZFast88Z
    So I do the math myself, and have determined the calculator must be wrong. I get the same answer as you do.
    Ok good LOL. I had to double check myself to make sure. :lol:
    Ill check all the other information in the morning by hand and verify the math is right. Funny thing is I just switched the units on the calculator from inch to mm and then the FPM came out properly. Weird.

    I will edit in the morning if other changes are needed.
    The bullshit stops, when the GREEN light drops.

    Only babies cry about the bottle.
  • raracing1
    raracing1
    Member
    • 46

    #48
    HI I do not have all the time of the world but why do you just start with a vg33 long block it`s heaven!
  • ZFast88Z
    ZFast88Z
    Senior Member
    • 1882

    #49
    raracing1 wrote: HI I do not have all the time of the world but why do you just start with a vg33 long block it`s heaven!
    That's exactly what I started with. I then bored it out to 97.5mm making for a VG37ETT.
    The bullshit stops, when the GREEN light drops.

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

    #50
    I was going by what the paeco kit had as it's specs in the auction. They were definately 97.5mm pistons. As stated, I'm sure you've done more math on it, and I know companies can be wrong in their assessment of the final displacement of an engine in many areas of their calculation. So I could trust your calcs moreso than an ebay auction 8) you're actually building the thing, right? But as you calculated. if the Paeco is 89mm, and the action it says 97.5, that would mean the auction was dead on @ 4 litres… They did not mention what is required. Maybe ductile iron sleeves that protrude well into the coolant jackets. Again, I'm not sure if that's a viable option, but the calculations point to it being possible. Whether or not the block can take it is another story!

    I went through the same thing trying to get good pistons for my high-comp RB30. I am thinking of having it stroked and getting longer rods and shorter pistons… to bump up the displacement. I've not calculated what it will turn out to be, but if I can have a high comp RB33DE, that would be awesome.

    I'm looking at building it up in the next year after I return from australia. I'll get a good idea of what's available there, and I'll tell my relatives to keep an eye out for me or purchase parts for me and ship them when I'm ready if they're willing to do so!



    [quote]ZFast88Z wrote:
    Originally posted by Careless
    Actually, from what PAECO says about their .250 inch stroker kit, if you use the supplied VG30DETT 97.5 mm pistons and the factory Z32 or forged Z32 rods, you will get a 4.0 litre.
    Are you sure they didnt say 87.5MM pistons? The VG30DETT is an 87mm bore. I have never checked the wall thickness of one but I cant imagine there would be enough material to bore out to 97.5mm (considering the VG30ET cannot come anywhere close to that dimension)

    So if we take into account that the stroke and bore on the Z32 is the same as the Z31 motor, and the cranks from either will fit the VG33 and allow for the same capacity, then the stroker kit with 97.5 mm pistons would reach 4.0 litres in much the same way as it would if it were on a VG30DETT, would it not?
    Some math for you:
    Bore Stroke Displacement
    87mm (stock) 83mm (stock) 2.99L(stock)
    87mm 89mm (Paeco) 3.19L
    87.5mm 89mm 3.22L
    91.5mm (VG33) 89mm 3.52L
    97.5mm 83mm 3.72L
    97.5mm 89mm 4.00L
    99.5mm (MAX) 89mm 4.17L

    Piston Speed:
    Stroke RPM Piston Speed
    83mm 6000RPM 3254 FPM
    83mm 7000RPM 3797 FPM
    83mm 8000RPM 4339 FPM
    89mm 6000RPM 3503 FPM
    89mm 7000RPM 4087 FPM
    89mm 8000RPM 4671 FPM

    When building an engine, I prefer to use 4500 FPM as the maximum piston speed. I know a lot of guys building drag race engines are well into the 5500FPM range. I have personally turned a 347" Small Block Ford to 9000RPM. Thats 5079FPM. The reason I choose 4500FPM as my maximum RPM (for a street/strip engine) is IMO its the best for both performance and reliability. I expect to shift the VG at 8500RPM, unless there is signifcant power made above that point. Then I will re-evalute.

    The reasons I didnt choose to use the stroker kit is three fold. I dont need the lower RPM torque offered from using a longer stroke, I dont like the idea of offset grinding a crankshaft to increase stroke, and the piston speed will limit the max RPM that I will feel comfortable using. As it is, I am worried about the integrity of the crankshaft. :twisted:


    [quote:30opqelo]I'm kinda glad I didn't go that route because the car has now 650km on it, and it made me 120 dollars today, so it's slowly starting to become a tool that I could have used a long time ago (I've never actually had my own car to drive wherever I wanted, whenever I wanted, so time was a factor in my build).

    Looking forward to seeing what you come up with, Zfast
    The cost associated with building this engine was far more then I care to discuss. It is definately NOT the best option out there, as Im sure just as much power could be made with a VG30 using the same turbocharger setup. A higher pressure ratio may be neccesary, but Im sure its obtainable. Would I do it again the same way? Absolutely. Would I recommend anyone do it? Not entirely. I would recommend this approach for someone who wants to use maybe a smaller single turbo, and achieve higher HP because of the increased displacement (say for street racing reasons).[/quote:30opqelo]
  • raracing1
    raracing1
    Member
    • 46

    #51
    [quote]ZFast88Z wrote:
    Originally posted by raracing1
    HI I do not have all the time of the world but why do you just start with a vg33 long block it`s heaven!
    That's exactly what I started with. I then bored it out to 97.5mm making for a VG37ETT.
    VG33 is all ready on the boring edge of the main cap support I deffinitively don`t recomend to go further than .020 or let your crank go away! I mean it.
  • ZFast88Z
    ZFast88Z
    Senior Member
    • 1882

    #52
    [quote]raracing1 wrote: [quote=ZFast88Z]
    Originally posted by raracing1
    HI I do not have all the time of the world but why do you just start with a vg33 long block it`s heaven!
    That's exactly what I started with. I then bored it out to 97.5mm making for a VG37ETT.
    VG33 is all ready on the boring edge of the main cap support I deffinitively don`t recomend to go further than .020 or let your crank go away! I mean it.
    LOL Oh ok. Let me go unbore my block.
    The bullshit stops, when the GREEN light drops.

    Only babies cry about the bottle.
  • -Strike-
    -Strike-
    Senior Member
    • 1968

    #53
    I think he meant the VG30 hah. The 33 block has a lot of meat.
  • ZFast88Z
    ZFast88Z
    Senior Member
    • 1882

    #54
    -Strike- wrote: I think he meant the VG30 hah. The 33 block has a lot of meat.
    Im really starting to wonder if anyone reads any of my posts in this or the other VG33 boring thread. I gave average wall thickness, and all the other information you need to know on boring the VG33 out to larger displacements, yet there is always a million and 1 questions and opinions on what Can and Cant be done.
    The bullshit stops, when the GREEN light drops.

    Only babies cry about the bottle.
  • SATAN
    SATAN
    Senior Member
    • 6782

    #55
    [quote]ZFast88Z wrote:
    Originally posted by -Strike-
    I think he meant the VG30 hah. The 33 block has a lot of meat.
    Im really starting to wonder if anyone reads any of my posts in this or the other VG33 boring thread. I gave average wall thickness, and all the other information you need to know on boring the VG33 out to larger displacements, yet there is always a million and 1 questions and opinions on what Can and Cant be done.
    You know what that means right? Don't post anything else until its done… Then when it is done, post up info, then people say it can't be done… You can say "Oh really? Take a look…"
    85 Z31 6.0 LSX turbo 766whp/792wtq
    04 GTO, LS6, big cam, porting, N20… underway for summertime daily driver.
  • ZFast88Z
    ZFast88Z
    Senior Member
    • 1882

    #56
    [quote]SATAN wrote: [quote=ZFast88Z]
    Originally posted by -Strike-
    I think he meant the VG30 hah. The 33 block has a lot of meat.
    Im really starting to wonder if anyone reads any of my posts in this or the other VG33 boring thread. I gave average wall thickness, and all the other information you need to know on boring the VG33 out to larger displacements, yet there is always a million and 1 questions and opinions on what Can and Cant be done.
    You know what that means right? Don't post anything else until its done… Then when it is done, post up info, then people say it can't be done… You can say "Oh really? Take a look…"
    It is done. The long block has been built for months. I'll post pictures after the thing runs and I know it wont destroy the block at the power levels we will be making. Id hate to post pictures of a static engine, and then everyone goes out and cracks blocks because they got running before I did. They are more then welcome to do it though.

    Physically IT CAN be done though.
    The bullshit stops, when the GREEN light drops.

    Only babies cry about the bottle.
  • badboyz31
    badboyz31
    Senior Member
    • 2403

    #57
    sweet I cant wait......I actually pay attention to what you post because it really has came in handy so far with my build
    1uz Swapped, lowered, flaked out '86 z31
    '72 Datsun 510 4dr, ka24de-T, slammed resto mod
    '84 z31 turbo, coils, wheels a.k.a the gfs weekend car
    '86 na2t parts for now a.k.a eventually will get running with a/c daily
    '83 280zx project backburner a.k.a ls turbo drag car one day
    Custom vg30et tube chassis drift exocet project
  • VG36ET
    VG36ET
    Senior Member
    • 190

    #58
    Patiently waiting to c a 3.8L+ Naturally Aspirated(reliable) VG in ANY vehicle!
    Ucked Fup!!!
  • F/A 300
    F/A 300
    Member
    • 48

    #59
    Hey guys. Finally back to my Z I got a 2000 s10 so the Z is now my fixer up car.

    I've read this whole post and I've wanted to put a vg33 in my car for awhile but now I really want to. I like the boring out to 97.5 mm. Though I don't think I would do the stroker because I want to run higher boost levels. I start at Wyo-tech march 28th maybe I can use their equipment to do some work.

    Are you running the stock crank in your car Zfast I don't remember. If so are you worried about it breaking?

    So sleepy
  • Careless
    Careless
    Senior Member
    • 13279

    #60
    if you're building it up. source your flywheel, clutch, crank, and aftermarket rods from a Z32 300zx, and get pistons custom made. that should get you started and with a heck of a lot of iron to strengthen that blocks bones and improve it's motor skills!