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4.0 whipple problems

Discussion in 'Engine/Tuning' started by pickup_man06, May 13, 2015.

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  1. pickup_man06

    pickup_man06 fast is never fast enough Established Member

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    heres my setup first off:
    -built 5.0 stroker, all the fancy stuff, not really important to know right now
    -4.0 with 3.5" upper
    --->using factory lower caged setup with an innovators balancer.

    question i have...blower makes too much torque, and is snapping the front piece off the pulley ring, which obviously, is causing me a lot of issues making boost, haha. i dont want to remedy this issue by feeding the car caged lowers, its expensive, frustrating, and not how i operate. i know they can be welded up, but thats still a bandaid, and they still break. i dont want to drastically change the setup, because it works, most of the time, and it makes power. so here is my dilemma, i want to figure out if there is any way to add reliability to the strength that the cage provides. ive heard of using the gt500 setup, which switches the blower drive to the inner side, and the accessories to the outer side. does anyone know if this can work? looking at pictures, the timing cover looks way to different to allow the accessories to bolt up and maybe even too different to work for even the blower? i dont know, im not familiar with gt500's much. looking to see if anyone has some experience to make this work for me, without doing anything crazy. mainly after the idea of the gt500 setup though due to production castings and increased crank snout strength. hit me with ideas :D
     
  2. fr03cobra

    fr03cobra Active Member Established Member

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    I hope i will be good on the 2.9 crusher. Did the metco adaptor/inovators west balancer and stock metco crank pulley. My crank was doubled keyed.
     
  3. pickup_man06

    pickup_man06 fast is never fast enough Established Member

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    oh yea, you should be just fine. there are guys running that and a studded crank snout on these 4.0's with good results, but i really liked the idea of the crank to block support the cage offers. it just was never intended to support 1000+ hp and a super blower like this. wish someone had something designed, guess ill end up paving the way :/
     
  4. SlowSVT

    SlowSVT Well-Known Member Established Member

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    "blower makes too much power" should read: "the torque required to drive the blower is sheering the pulley ring"

    With a 4.0 expect crank/pulley problems the snout was never designed to handle that kind of load. Stay out of big boost and no sudden rpm changes and you should be OK
     
  5. pickup_man06

    pickup_man06 fast is never fast enough Established Member

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    yea, thats what it was meant to say.

    and yea, i know it wasnt meant to support that, the only sudden rpm changes would be letting out of the throttle at the end of the run. thats actually what sheared it this time. just looking mainly to see if anyone with more time invested than i has tried the gt500 setup, or has come up with anything more creative than the few techniques previously mentioned. big boost isnt a choice with this blower, even on a super efficient engine and the biggest pulley combo available its right around 23-24#. on a 4.6 anyways
     
  6. pickup_man06

    pickup_man06 fast is never fast enough Established Member

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    and currently im making 25-26# with 19* timing. i havent added the +2* tune yet. no point til i get this figured out first. figured i should mention that too
     
  7. cj428mach

    cj428mach Well-Known Member Established Member

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    Have you thought about just getting a new caged lower machined? I think the guy that custom built caged 4lb lowers actually had one that all the parts machined new and was much beefier.

    Off topic but do you have any broken caged lowers you want to part with? I was thinking about trying to build a custom caged lower pulley for my car, I'm needing a good stock pulley.....just the black part that the belt rides on that holds the bushings. If you have one off a broken pulley you'd like to part with pm me please.
     
  8. pickup_man06

    pickup_man06 fast is never fast enough Established Member

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    ive thought about that, but its gonna be godawful expensive. i dont even know who did the r&d on that last 4# either. id be interested in one of those too, but then again, so is EVERYONE.

    as far as a used broken one, yes, i have just this one so far. ill be happy to part with it, once it is off the car. ill send you a PM
     
  9. SlowSVT

    SlowSVT Well-Known Member Established Member

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    The problem is inertia loads imposed by the mass of the 4.0 rotors which are known for snapping mod motor crank snouts. Don't bother adding a 2nd keyway which will only weaken the snout further.

    Handy work of a 3.4

    SnappedCobracrank_zpsceccfb96.jpg
     
  10. pickup_man06

    pickup_man06 fast is never fast enough Established Member

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    no second keyway eh?

    not sure if its just my computer or not, but i cant seem to load that picture you posted
     
  11. Mystic03

    Mystic03 Active Member Established Member

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    Dang sorry to hear your problems hopefully you figure it out
     
  12. ctgreddy

    ctgreddy Well-Known Member Established Member

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    that'd be a no go on the gt500 setup. Everything on that car is completely different. In order to get it to work you'd essentially have to buy a 5.4/5.8 longblock with all accessories, blower, pulleys, etc. Since you said a custom "beefed up" lower would be crazy expensive I'm assuming you wouldn't want to go that route.

    Sucks to say it but I think the best thing to do on these cars once you max out a 2.8/2.9 would be a turbo/cogged procharger. Sucks but the snouts were not designed for anywhere close to the power you're at. And it seems like you've found the limit on the stock caged lower. The only way to reliably do it is the turbo/procharger route. Or you can try and just put on a normal metco lower and pray it survives. That will be stronger than the caged stocker but then you're relying on the crank snout.
     
  13. Givens

    Givens I wanna go fast Established Member

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    I thought the stocker was stronger than any of the aftermarket lowers because of the cage.

    The double key is a no go as it weakens the crank.
     
  14. pickup_man06

    pickup_man06 fast is never fast enough Established Member

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    the stocker is technically the strongest due to the cage yes. its just where the pulley threads onto the shaft is what is weak and blows apart.
    the metco pieces would bend or break the crank snout for sure.

    ctgreddy, that is what i had in mind, but just browsing thru the classifieds and random other sites yesterday has netted me with the idea that the gt500 stuff would cost more than studding the crank most likely. i will just have to talk to a local machinist and see what can be done with this lower pulley setup.

    anyone know who the guy was that machined the 4# caged pulley? maybe he can give me some advice.
     
  15. pickup_man06

    pickup_man06 fast is never fast enough Established Member

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    thanks mystic03, ill get something figured out!
     
  16. SlowSVT

    SlowSVT Well-Known Member Established Member

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    I hate to say none of those option will address the inherent weakness of the mod motor crank snouts. Any blower that gets larger than a 2.9 starts to run into problems. If a 3.4 can snap a crank a 4.0 will be more even obliged to do so. It's the inertia loads in both directions, just watch your tach needle and imagine the blower is spinning 1 1/2 times engine speed following the crank. Add the mass of the damper, accessory drives, water pump and the alternator and you start to appreciate the loads that tiny snout needs to deal with on a crank design that never was intended to turn a supercharger. They always break right at the undercut fillet which Kellogg used to save on machining cost at the expense of adding a stress riser. An article in this months issue of MM&FF featured a 5.8 GT500 built to the "Moooooon" with a KB 4.7 on top :eek: From what I could gather was the crank gave-up the ghost fresh off the engine stand, not surviving that build was a fore gone conclusion!

    Never heard of a 2.9 or smaller breaking anything. I say if you want to run a 3.4 or larger consider a billet crank.
     
  17. pickup_man06

    pickup_man06 fast is never fast enough Established Member

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    slowsvt, thank you! this is the kind of thought provoking conversation i need. and this is how creative solutions form. mine is actually single keyed at the moment too, so no extra weak spots.

    ive never encountered someone breaking a snout with a 3.4, although ive heard of lots of heads lifting. the 4.0 is quite a bit larger, and ive heard of snouts being badly bent by the pioneers of this blower combo.

    the 5.8 build (cool no doubt!!) is just a bad idea anyways, not even because of the snout, just the crazy bore x stroke ratio is enough to turn me away.

    when i pull the motor eventually to build it for stupendous power, because it always happens, ill look into billet rods and crank, and go for broke. but for now, i dont wanna pull it apart since its freshly come alive again. but i am for certain keeping the caged lower idea around because seemingly that is the only way to continue its life. ill just have to spend the money to make a better design that can actually support the power i make and the torque the blower makes.
     
  18. MalcolmV8

    MalcolmV8 Well-Known Member Established Member

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    What HP levels are you running and boost levels? From what I've gathered reading the thread you're really not pushing the 4.0 all that hard. Why not switch to a 2.9 crusher and spin the hell out of it? Probably make the same or more power and not deal with the heavy loads of spinning that 4.0.
     
  19. HuntFishCobra

    HuntFishCobra Formerly MarkOPKS Premium Member Established Member

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    didn't BADASS03SVT run a 4.0 whipple on his car for a while? Maybe he'll chime in
     
  20. pickup_man06

    pickup_man06 fast is never fast enough Established Member

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    900 whp, 25# malcolm.

    truthfully, i like being different though too. FIRST mystic with a 4.0, and one of the first in general. its not your average build. and its an eye catcher and conversation starter. once i figure this last piece out, it should be a 'reliable' racecar. ha, if that even carries any weight at all. :D

    and cliff, jim, jake, and harold have all run one, raced it, etc. cliff got tired of breaking lowers and sold his to me. jim and jake studded their cranks and ran a metco/innovators setup and harold used the stock cage but TIG welded the triangular piece to the shaft. im told hes broken one though, even welded. jim and jake and the few others, i dont know how theirs held up, but i believe they had one season of success.
     
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