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  1. #1
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    Default does my cam choice fly

    i admittingly do not know enough about choosing cams to make this decision without asking.

    in looking at their website this setup looks like what i want but i wanted to make sure

    here is my setup
    454
    torker II intake (wont change for hoods sake)
    speed demon 750
    headers
    67 L36 427 heads
    2500 rpm stall convertor
    3.55:1 rear end

    i am thinking of this cam set.
    COMP Cams: Xtreme Energy™, XE274H
    Very Strong Mid-Range Torque and Throttle Response


    i like the comp cams set because it comes with everything necessary from cam, to springs, to lifters, to timing chain, to pushrods etc etc.
    it takes the guesswork out of what supporting parts you need to go with the cam upgrade.

    i have first hand experience with the XE lineup in my old mustang and was very pleased with it but am open minded enough to try a different version out there if necessary.
    thanks

  2. #2
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    Have u calculated your final compression ratio?
    This is a big influence on the cam choice and how detonation sensitive it is. With iron heads, this limits your compression to around 9:1. With aluminum heads it is around 10:1 because they shed heat faster than iron.

    The biggest factor in making power is the heads. Going with modern cylinder heads will really wake up your 454. Another option is to port your existing heads to make more power. Going aluminum is a great way to go because stock iron heads are so heavy. I am currently building a 540 engine and went with Merlin alum heads. They flow good and the exhaust ports are in the stock location unlike darts and afr's.

    Picking the camshaft is the hardest part. I think going milder rather than more radical is the way to go. More vacuum, nice idle, etc.

  3. #3
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    It will work well , if it lasts , I will never go for a flat tappet hydraulic again as I have lost 2 cams in 2 diff cars in the last yr , evidently there are problems with oils , lifter mnfgrs etc etc. I would go roller hydraulic and perhaps 1 stage more aggresive. You already have the stall and rear end and an engine that puts out prodigious torque , you could proably do with a little less power under 3000?

  4. #4
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    I agree with Ed. I would pick the next smaller cam than the one you picked. I like street cams to be no larger than the mid 220's at .050 dur.

  5. #5
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    the next smaller one is the xe 268 which apparently a lot of people here have. i was looking at that one before the headers and converter upgrade.

    i am not sold on the xe line though, i have read a lot of them are wiping. in contrast though i put a xe256 in my 302 mustang, used rotella t with comp cams break in oil, 3000 rpms for 20 minutes right at start up and it is running fine.

    there is also the high energy and thumper line.

    comp cams recommended over the phone the xe268h.


    as far as the final compression ratio. i know stock the 72 454 had 8.5:1.
    it no longer has the stock heads though. it has heads off of a 67 L36 427 which supposedly has smaller combustion chambers so i am not sure of the compression ratio now. id like to know honestly. that info would indeed help in cam choice but i am not sure how to calculate it.

  6. #6
    Member 73shark's Avatar
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    Might check in a TRW piston catalog. When I was picking a piston to use, I wanted to up the CR from 9:1 to ~10:1 w/ my stock heads. Their catalog shows different CRs for different head combustion chamber volumes. As it turned out, the 11:1 LT-1 pistons were the ones we went with.

    Someone here can probably conjure up what your '67 head volume is.
    Save the wave

  7. #7
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    on this site, it shows the specs for various BBC heads
    Big Block Chevy Engine Parts Identification

    my heads are casting #3904390.
    it says that they are closed chamber heads 98.4cc

    oem 454 heads for a 70 to 84 454 say open chamber 113.0cc

    whatever all that means

    coincidently it also has the grind information for the stock cam.
    stock 454 cam is
    lift 460I/488E
    duration 213I/217E

  8. #8
    Member 73shark's Avatar
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    Find a parts store or engine rebuilder that has a TRW catalog and find your piston and see what the CR is w/ the 98.4 cc head is. Since you didn't say what your pistons are, it's hard to say.

    BTW, I've read where the open chamber head is a better performance head than the closed chamber heads.
    Save the wave

  9. #9
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    i really dont know what pistons are in it. i am going to guess stock. but since somewhere down the road the heads were changed out there is no telling what is in it now.

  10. #10
    Member 73shark's Avatar
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    What year is your engine?
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  11. #11
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    it is a 72 4 bolt main.
    the stamp by the tranny on the drivers side says so.


    it is definitely not the original engine.
    the VIN tag by the passenger head is blank.

  12. #12
    Member 73shark's Avatar
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    I guess you're pretty much stuck 'til you pull a head and cc a piston.
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  13. #13
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    ok, i finally got around to getting to a machine shop. according to them without pulling a head and actually looking the difference in ratio from the 454 heads to the 427 heads would only be .2-3 points so i was told a good comp ratio to use for cam choice would be anything from a stock head choice of 8.5:1 to 8.7:1.

    so that being said,
    with the stall, headers, and gear ratio i have already mentioned which would be the better cam choice

    the xtreme energy xe 268h
    the high energy 268h
    or the magnum 270h.

  14. #14
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    Have you downloaded Compcams Camquest yet?(its free on their website) It will help you pick out a cam for your car. From the three cams you listed i would go with the Xtreme 268 cam,it is the newest design out of the three and has the most lift.

  15. #15
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    i tried compcams camquest.
    it recommended different cams each time i ran it with the same specs.

    i originally was looking at the xe268h and one of the few times i was able to get a hold of comp cams on the phone they recommended it as well but i hear so many times that it is bad about wiping lobes on break in.

    not sure i want to risk it.

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