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question about 440 cams

Discussion in 'Performance' started by jormymex, Oct 9, 2019.

  1. jormymex

    jormymex New Member

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    I am rebuilding a 1978 440, Stock heads, I will raise the compression about 9.6:1 with KB pistons, Edelbrock, dual plane manifold, and 750 cfm edelbrock carburetor, I bought a pair of 1969 HP exhaust manifold. The idea is to put the engine in a 1968 Coronet 440 Station Wagon.

    I buy a Compcams kit that include cam, chain, springs, etc. The cam that come with the kit is a 260H series High Energy 212/212 (1000-5000 rpm, valve lift 0.44 both, advertise duration 260).

    At this moment I am in doubt to buy a 268H series cam (only the cam not the kit, to use the other components, I checked and all the components are the same)

    the cam is Compcam 268H Series High Energy 218/218 (1200-5200 rpm, valve lift 0.454 both, advertise duration 268)

    It will worth the change or is useless? thank you
     
  2. dana44

    Ad-Free Member

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    Both these cams are pretty mild and you would barely feel the difference between the two cams, as both cams are pretty close to stock lift, so basically it depends on whether or not you want to spend the money on the slightly larger cam. If you didn't have a cam in the first place, the 268H is a good mild RV (old term) cam that is a slight step above stock.
     
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  3. jormymex

    jormymex New Member

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    Thank you so much, I have already the 260H, my first project was to build exactly a mild overstock performance, I want to put de 1978 190 HP 440 on the 60´s specs only, about 375 HP. If there is no noticeably difference between two cams, maybe is wiser to keep the 260H. I want to use the station wagon on the highway only, and get a good response with the pedal
     
  4. DC-93

    DC-93 Well-Known Member

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    260H is close to a 440 4 barrel cam used in a Chrysler New Yorker or other C body car.
    The 268H is more like the used in a 440 GTX package or Charger R/T.

    Hope this helps. Personally, I'd keep the 260h.
     
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  5. jormymex

    jormymex New Member

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    Thank you so much for your answers, I think 268H could be a better choice, but no so different to justify the cost. Again thank you so much
     
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  6. dana44

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    And from the sounds of what the 440 is going into, the smaller cam will give you a little more low end torque for the highway cruising, so spend the cam money on something else and enjoy.
     
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  7. jormymex

    jormymex New Member

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    Thank you again, I really learn a lot from you, Really this is a basic configuration for a 440, maybe in a couple of years, I could swap the heads to aluminum ones, and put a more agressive cam, I really want the car for weekend drivings in highway or mountain roads.
     
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  8. jormymex

    jormymex New Member

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    Please one last question: I look for this cam: Xtreme Energy 224/230 (1600-5800 RPM, Advertise intake duration 268, Advertise exhaust duration 280, Intake duration 0.50 lift 224, Exhaust duration 0.50 lift 230, Intake valve lift 0.477 Exhaust valve lift 0.48) I discarded this cam because it says I need a different set of valve springs. Excuse me I don´t know much about cams, I know the general principles but really I can´t understand all the numbers for the "real life applicattions", But I think is a cam that I could use without mayor modifications. Can you let me know a little bit more? I really appreciate.
     
  9. DC-93

    DC-93 Well-Known Member

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    Performance cam. Too much for what you are doing!
     
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  10. dana44

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    The reason for the new valve springs is not that stock won't work, it's that the higher rpm to make the real power with this cam requires springs that will not float as easily. The longer durations on the lobes allows more purging of the exhaust and more air into the engine, which, at lower rpm kills the bottom end, but allows the engine to rev higher. The longer duration bleeds off cylinder pressure, thus lowering the dynamic compression ratio at lower rpm, than at higher rpm, since things are spinning quicker that pressure then is able to build and make more power at the higher rpm. Since the bottom end is dead, or reduced because of the lower compression from the overlap and not compressed for power, one usually needs a higher stall converter in the transmission to have more bottom end takeoff. Mopar makes a stock 11 inch torque converter, used on police, RV and big block engines (some) that has a 2000 stall in them, so that really helps, but as the specs say for the cam, it really doesn't start working with this much actual duration until you are above 1800rpm, so not a real good street cam, or especially for a highway cruiser or tow vehicle.
     
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  11. jormymex

    jormymex New Member

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    As always thank you so much really. That clear all
     
  12. Fast Eddie

    Fast Eddie Valued Member
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    Over camming and over carbing are the 2 biggest mistakes a lot of people make. It causes a major low end "bog" most of the time that results in the engine not being able to accelerate quickly due to the fact that the fuel/air mixture is not able to feed the engine due to low engine speed. As the engine speed finally starts to increase then the fuel/air mixture and the air flow starts to increase into the engine and max power for your engine is made. By that time your competition is long gone!
     
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  13. jormymex

    jormymex New Member

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    Thank you, It´s really hard, because here there weren´t much big blocks and the experience of the mechanics is low, but with the ideas you gave me, I think I am beggining to understand the concepts. Thank you so much really
     

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