Building a nice street car.

Mopar Performance Issues

  1. AdamR

    AdamR Big Member

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    or at least my idea of it. I really want to build a nice street/strip package. Nothing super fancy, nothing super fast. Looking for low 12s, (dont want a bar in it) , good torque and mid range, good throttle response. This isnt a daily driver but a weekend street toy.

    The car is all steel, bench seat interior, I want it as stock as I can keep it. Im guessing it will be around 3200lbs.

    I want to make some changes to my 340, Its 11:1 compression, 260/265 @.050" solid cam. Victor intake, Proform 750 Carb, Ported iron heads flow 270/165 @.500"

    My plans for the motor are a smaller solid cam, and a dual plane intake. I would like to use a stock AVS intake but may use a Performer RPM, Any recommendations for the cam ? Im going to stay with a solid.

    Exhaust will be 1-3/4" Hooker Super Comps. either 2.5" or 3" pipe with Flowmaster. what size pipe would you go with ? I know the flows arent the best mufflers but I love the sound.

    The tranny is currently set up wih a 2.77:1 low gear and a manual valve body. Im going to swap to a automatic valve body (sometimes I just want to stick it in drive) anyone know of a good automatic valve body or a good shift kit. I have used the cheap B&M kits with out much luck.

    The converter is a Turbo Action tight 8" that stalls to 4200rpms. Works great so it will stay.

    Gearing I planed on 3.91s or 4.10s with a 26 or 27" tires ?


    Any ideas, recommendations or comments ?
     
  2. 408duster

    408duster Well-Known Member

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    I sourced a great auto valve body from Rick Allison of A&A Transmission fame. He claims you wont find another that shifts faster than his. Currently in my 74 Duster 360 with 727 and 3.91 gearing. He is great to work with, over the years I've bought several items from him.
     
  3. Longgone

    Longgone John/68 Barracuda & Dart

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    My car is street with 11-1 CR and needs about a 50/50 mixture of Cam2 to keep it from spark knocking if the timing is set where it should be. You might see what you can do to bring yours down, maybe thick head gaskets and the right cam. I`d run the Performer intake , go 2.5" exhaust to keep the temperature up , run a 27" tire, and if you could afford it (which I know you`ve got a growing family and can`t but) invest in a 4spd AT w/od so you can cruise. That`s the one thing I really miss in my car is the ability to just hop on the interstate and ride. Don`t get me wrong, I LOVE the acceleration, just miss the freedom of the road. We`ve got car shows and places I`d like to take the car in and around the area here almost all year around.To get there you must take the interstates to cross the rivers and 60 mph at 3200 rpm for an extended period of time will grind on your nerves(and your bearings) so either a lower gear in the rear or an OD transmission are your only choices for rpm relief. It`s a real balancing act to get a blend of street and track blended together, but you learn what works for you as you go along. Good luck!
     
  4. AdamR

    AdamR Big Member

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    Im glad you mentioned the 50/50 mix. I was told to run 5 gallons of Cam2 with 10 of pump gas. With the smaller cam my cylinder pressure is going to go up sp I may need more.
     
  5. 388dart

    388dart Well-Known Member

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    Thinking along the same lines - here is what Bullet Cams recommended to me
    CRA 287/292 H8
    DURATION @.050 = 240/248
    LOBE LIFT = .360/.355 x1.5= vl540/532
    LOBE SEPARATION = 108
    AT .050 = IO 16 BTC
    IC 44 ABC
    EO 56 BBC
    EC 12 ATC
    LOBE SEPARATION = 108
    INTAKE CENTERLINE = 104
    EXHAUST CENTERLINE = 112
    I added the info to my Dynasym and it just makes excellent tq and peak hp is at 6k in my combination. Send them a profile of your build and see what they come back with.
    Gears I would go with 3.91 and 27" dia tires = ±3100rpm @ 60mph.
     
  6. Jim Lusk

    Jim Lusk Well-Known Member

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    If you want true driveability and excellent acceleration you need mild large cubic inches with less gear. Either stroke the 340 or go to a big block. I can jump in my son's Dart GT convertible and drive anywhere. It is traction limited, but on purpose (don't want to twist that convertible body, even with sub-frame connectors). It wouldn't take much more cam to put the 440/4sp car deep into the twelves, though, and it would still be very streetable.
     
  7. mikesduster

    mikesduster Well-Known Member

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    adam

    what do you have for a cam in there now??...i really dont think a cam change will help in which type of gas you use BUT dropping the comp. from 11:1 to 10:1 will.

    you have a pm.
     
  8. moper

    moper FABO Gold Member FABO Gold Member

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    Adam, I think you will have issues with detonation running 11:1 and a smaller cam. If you dont already. Street car means using available fuel. I would add a thicker head gasket, or enlarge the chambers to drop it down to 10:1. Then run a slightly smaller cam, a hydraulic would bleed off more pressure. The exh port is hurting you too. I would not run a single pattern cam with a 60% flowing port. Something like the XE284H. I think for a solid the way to go is keep it larger, like the XS274S.
     
  9. AdamR

    AdamR Big Member

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    Moper, I'm not worried about the fuel. I'll mix in some good stuff.The way the motor is set up now it needs 5 gallons of 110 to 10 gallons of pump. I may need to go 50/50 with a smaller cam. For a cam I was thinking a XS282S or a Hughes Engines 4852. I was also wrong on my flow numbers. They are 260/173 at .550" lift
     
  10. moper

    moper FABO Gold Member FABO Gold Member

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    Those number sound more like Dwayne...lol. I was wondering about that...
    If you have access to good fuel ,then that's fine. I do too, but most guys can only find Av gas or similar. I'd rather run pump gas...lol.
     
  11. rumblefish360

    rumblefish360 So close, yet so far away FABO Gold Member

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    I'd do the carb on top of a RPM and 2.5 pipe. Gear and tire sizes listed are close and would feel about the same. You'll probably notice it more at the track between 4.10 & 26's and 3.91 & 27's that would be more street freindly.

    Is a roller cam out?

    Otherwise, a cam (@ .050) of a min. of 230 to a max of 240.
    (The 10* spread is large and general, I know, but between the gears and tires mentioned and a unknown operating RPM band/range, along with what your idea of the car should be, it's hard to zero in on something. But with that said....)
    I would look at something like a Extreme lift comp cam with your ported heads.

    Speaking of heads and compression, have you thought about a barrier coating inside the camber? Cleaning pistons and coating them?
    Cometic gaskets offer a wide verity of thickness' to drop the ratio.

    I know the suggestions are stabs in the dark. I'm not familar with your build. But there ment to help with detonation and overall ratio. I have used the MoPar steel shims on a small block before with very good results and longevity.
     
  12. AdamR

    AdamR Big Member

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    Rumble, I don't know if coating the chambers would be enough to keep it out of detonation. Id rather just run the good gas and be safe. These pistons have had a lot of extra weight removed and may not hold up to any detonation at all.

    For tires I'm going with a M/T drag radial do it will most likely be a 235-60-15 so 26" tall.

    The cam I'm thinking of is a a solid version of the extreme series its around 240 intake 250 exhaust.
     
  13. rumblefish360

    rumblefish360 So close, yet so far away FABO Gold Member

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    Sounds good Adam. Extreme hi-lift?
     
  14. AdamR

    AdamR Big Member

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    I dont think its a 904 tappet cam but I dint think there is really going to be enough difference in power that it would be worth the extra stress on the valve train.
     
  15. rumblefish360

    rumblefish360 So close, yet so far away FABO Gold Member

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    Agreed. I really do not think it is an absoulte thing to get. Some people do.
    You have to spec a cam for full advantage from any grinder. On the street, it's small potatos.
     
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