Formula S 340 cam specs

Mopar Performance Issues

  1. Charlie's Dart

    Charlie's Dart Active Member

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    Does anybody know the specs on a formuls s cam (smallblock) and were these pretty good cams / what rpm range were they used ? Thank you .
     
  2. moper

    moper FABO Gold Member FABO Gold Member

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    IIRC, the '68 only 4sp cams were slightly bigger than any other used. So if you have a '68 Formula S, that would be what it came with. After that, there is only one cam grind I think. It's a decent peice, with power from about 1500-5500, but will spin higher properly tuned. Much better modern grinds around tho, and probably easier to find...
     
  3. Jim Lusk

    Jim Lusk Well-Known Member

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    ALL 340s except 68 four speeds used the same cam. Even today they are a great cam.
     
  4. fishy68

    fishy68 Tyr Fryr's Inc. FABO Gold Member

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    I believe several sources are selling regrinds of the 340 4 spd cam Moper and Jim refered too. Summit has one listed under their name brand and Mopar perf. has one listed also. I think Crane also reproduces it. All the aftermarket ones I've seen have the number 6901 somewhere in the part number. For instance Summits part number is SUM-6901. Only mopar perf. is different.
     
  5. Longgone

    Longgone John/68 Barracuda & Dart

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    The 68-340 cam with a manual trans spec`ed as 276* intake and 284*exhaust with a .453" lift. HTH.
     
  6. Charlie's Dart

    Charlie's Dart Active Member

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    Thanx for the response on this article guys, since I posted this I've added elec ignition and changed the rear gears to 3:91's . I have a holley 600 on it now and was wondering if a 650 double pumper would make a big difference ? Now it seems a little sluggish . By the way I do have the Formula "S" 4 speed cam in my stock 69 340. Charlie
     
  7. dodgetkboy78

    dodgetkboy78 EDELBROCK HEADS SUCK!

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    I believe the 340 cam from 68 was the same spec as the RB magnum cam, was it not?

    If you're buying a new cam, the 268/276 voodoo makes more power across the whole range, idles choppier, and has more snap from the tighter lobe sep.

    And you can say, nah, it's got the 268 340 cam, I swear. LOL
     
  8. 70 DUSTER CRATE

    70 DUSTER CRATE FABO Gold Member FABO Gold Member

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    Way back when, My 1971, 340 came with a Thermoquad. There are different views on the true CFM, but it was more than 600. A great street carb, and after a few mods, it came to life. My hedders helped a bunch.
     
  9. crackedback

    crackedback FABO Gold Member FABO Gold Member

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    340 automatic specs were 268/276 .429/.444

    manual cam, the auto exhaust lobe on the intake and the 440 magnum exhaust lobe for the exhaust to end up with 276/284 .444/.453
     
  10. Isaac

    Isaac Active Member

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    They're a good cam if you're racing, running a stock type of class.The best oem small block chrysler flat tappet cam imo.I've also seen good success in oval track racing where stock/oem cams are supposed to be used. They're also a good way to get great peformance out of a street 318.. they aren't to wild but will really juice up a 318 or any LA for that matter.1500- ~6k if you use the right valve spring.Great camshaft.
     
  11. dodgetkboy78

    dodgetkboy78 EDELBROCK HEADS SUCK!

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    The only downfall of the OEM cams were the wide lobe center. If you took that cam, and brought it from the stock 114* to 106, it would be a real nice cam, but I'm not sure what the factory widened them for. Idle quality maybe? They are nice to the valvetrain too, the close the valves nice and slow.
     
  12. moper

    moper FABO Gold Member FABO Gold Member

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    I think they widened them for less overlap. Overlap ina warranteed engine can be a killer.. Fouling plugs, poor economy, fuel smells at idle... As much as they wanted power they also had some marketing and potential costs in mind.
     
  13. dodgetkboy78

    dodgetkboy78 EDELBROCK HEADS SUCK!

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    True....... But.... WEEEEE WAAAAAANT POOOOWWWWEEERRRRRRR!!!!!!!!!!


    I actually get better MPG on the highway with the closer lobes..... But they do stink.
     
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