boring a vg30 out to vg33 will Not work

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  • #31
    [quote]SATAN wrote: [quote=ZFast88Z]
    Originally posted by badboyz31
    well guys I need to keep this thread alive because I think, I'm going to be the one to do this, and I will proudly be the test subject for such a great engine.

    well to start off I should hopefully getting a vg33 bare block this weekend or so. First off would to actually get the block bored out to work with the 4.0L stroker kit for it, with a not so high compression for boost.

    plans after would be try to twin turbo charge it.

    well I really have someone to actually help me build this, but im going to try and do as much as possible myself.
    UMMM HI! WELCOME TO LAST YEAR!

    The engine sitting in my car is a 97.5mm bore stock stroke VG33. This is the engine that will be utilizing the twin GT35R setup. My block had enough wall thickness to bore it all the way to 99mm and leave sufficiant wall thickness for a decent amount of boost.

    Im not a fan of offset grinding a crank to increase stroke. Therefore I wont use the stroker kit.

    Is that the stroker kit he is talking about? I have only heard of one stroker kit and I THINK it is from JUN??? I don't know. But, yeah if you are planning on making big power, then offset grinding the crank is not the best coarse of action IMO.
    well, I know this is a thread from last year, but I still have not heard of anyone doing it yet and actually completing it, but maybe I'm not reading enough. I still want to do this though, because I have nothing better to do with my life outside of school and work.

    ZFast88Z do you have a build thread for this engine?
    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
  • #32
    badboyz31 wrote: ZFast88Z do you have a build thread for this engine?
    No, I stated up front when I started the build of this car, that no pictures would be posted until after the build is completed.

    I dont mind answering any questions you may have. I will tell you up front that you will be needing custom head gaskets and custom pistons and that custom means $$$
    The bullshit stops, when the GREEN light drops.

    Only babies cry about the bottle.
  • #33
    [quote]ZFast88Z wrote:
    Originally posted by badboyz31
    ZFast88Z do you have a build thread for this engine?
    No, I stated up front when I started the build of this car, that no pictures would be posted until after the build is completed.

    I dont mind answering any questions you may have. I will tell you up front that you will be needing custom head gaskets and custom pistons and that custom means $$$
    ok sweet, i actually cannot post anymore pics of the crap being done to my Z until after its done, according to the person helping build my Z up. Yes I know what custom means, and I mean I have done all I want to the Z as of now so, I was pursuing and researching this and have sourced the vg33 block. So I'm going to go ahead and go through with it. Only person I will be talking to about it, is the only other person I know doing it and that would be you my friend.
    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
  • #34
    Reference this thread. I posted a lot of information in it.

    viewtopic.php?f=1&t=13186
    The bullshit stops, when the GREEN light drops.

    Only babies cry about the bottle.
  • #35
    ZFast88Z wrote: Reference this thread. I posted a lot of information in it.

    viewtopic.php?f=1&t=13186
    thanks a lot
    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
  • #36
    ZFast88Z wrote: PAECO offers a VG stroker kit that increase stroke by .250 inch. When I did the math when i first started overboring the VG33 I found it was possible to make a 4.0L VG30 when combining the stroker crank with a 99mm "Safe" overbore.
    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.

    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?

    I'm sure you did more finite calculations than what I read regarding the stroker kit that was for sale, and from my RB30 research, I can agree with your calculations that differ from theirs. Heck, piston manufacturers for the RB26 can't even get their combustion chamber volumes right… So I'm glad you went ahead and made that VG38. That should be a monster, and would really show the potential of the later castings.

    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
  • #37
    Careless wrote:
    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:


    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).
    The bullshit stops, when the GREEN light drops.

    Only babies cry about the bottle.
  • #38
    ZFast88Z wrote:
    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).
    And this is my approach. I figure just cram as much air into the engine as you can. You can make anything breath with enough pressure behind it! :lol:
    85 Z31 6.0 LSX turbo 766whp/792wtq
    04 GTO, LS6, big cam, porting, N20… underway for summertime daily driver.
  • #39
    To blow all six pistons right out the hood, for a new ventilation system. :nanan?re
    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
  • #40
    Its all about your PLAN.....Pressure Length Area Number

    I just chose to increase 3 out of the 4, instead of 2 like you. We all know that 75% is better then 50% right. :nanan?re
    The bullshit stops, when the GREEN light drops.

    Only babies cry about the bottle.
  • #41
    Zfast… What formula are you using? Cause those aren't the numbers I get. They are close, but not the same.

    Formula for piston speed is as follows

    Piston speed in FPM = stroke in inches x RPM/6

    Stroke 3.27 (83mm) x 8000 = 26160 divided by 6 = 4360 Feet per minute. Oh yes, and it is feet per minute not second LOL.
    85 Z31 6.0 LSX turbo 766whp/792wtq
    04 GTO, LS6, big cam, porting, N20… underway for summertime daily driver.
  • #42
    SATAN wrote: Zfast… What formula are you using? Cause those aren't the numbers I get. They are close, but not the same.

    Formula for piston speed is as follows

    Piston speed in FPM = stroke in inches x RPM/6

    Stroke 3.27 (83mm) x 8000 = 26160 divided by 6 = 4360 Feet per minute. Oh yes, and it is feet per minute not second LOL.
    I was using 3.2677"

    And yes, it is feet per minute…I just like going fast. I am allowed one retard moment a day right?
    The bullshit stops, when the GREEN light drops.

    Only babies cry about the bottle.
  • #43
    [quote]ZFast88Z wrote:
    Originally posted by SATAN
    Zfast… What formula are you using? Cause those aren't the numbers I get. They are close, but not the same.

    Formula for piston speed is as follows

    Piston speed in FPM = stroke in inches x RPM/6

    Stroke 3.27 (83mm) x 8000 = 26160 divided by 6 = 4360 Feet per minute. Oh yes, and it is feet per minute not second LOL.
    I was using 3.2677"

    And yes, it is feet per minute…I just like going fast. I am allowed one retard moment a day right?
    HOLY SHIT DUDE, MY PISTON IS FASTER THAN MY CAR!!!!!! :nanan?re

    Even then I get 4356.9333 FPM. You sir have run out of retarded moments for the day! :lol:
    85 Z31 6.0 LSX turbo 766whp/792wtq
    04 GTO, LS6, big cam, porting, N20… underway for summertime daily driver.
  • #44
    SATAN wrote:
    Even then I get 4356.9333 FPM. You sir have run out of retarded moments for the day! :lol:
    I'm using a calculator that is part of Desktop Dyno. I just plug numbers in and get an answer. So either the program is wrong, or your doing math wrong. I just put the numbers in again and got the same answer


    HOLY SHIT DUDE, MY PISTON IS FASTER THAN MY CAR!!!!!!
    Considering neither move, wouldnt it be a tie? :nanan?re
    The bullshit stops, when the GREEN light drops.

    Only babies cry about the bottle.
  • #45
    So I do the math myself, and have determined the calculator must be wrong. I get the same answer as you do.
    The bullshit stops, when the GREEN light drops.

    Only babies cry about the bottle.
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