7.4L Cam shaft options

Discussion in '96+ Vortec Performance + Computer Swaps' started by cheerdude63, Oct 30, 2018.

  1. malibu795

    malibu795 Newbie

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    so first post.... some info I have found...cant find a bunch of stuff I found earlier... 12552296 camshaft is in my truck...
    GM#12552296
    .004” 280,299
    .006” 266*/284*
    .050” 204*/209*
    .200” 113*/114*
    Lift .480”/. 483”
    ICL 115.5*
    ECL 120.5
    LSA 118*

    GM#12551622
    .004 300*/ 300*
    .006 288*/288*
    .050” 225*/225*
    .200” 125*/125*
    Lift .483”/. 483”
    ICL 109*
    ECL 122*
    LSA 115.5*

    24502611 is the camshaft that is in the 454HO and 502HO crate engines
    .050" 211*/230*
    lift .510"/.540"
    LSA 112*

    HT502 crate engine has the above mentioned 12552296

    most truck engines have a 2.065/1.725 valve 100CC combustions for heads..
    I did a 468 gen 4 BBC build while back did ~380/540 at the crank, at rough rpm 5000/2500,with over 500tq from 2000-3800rpm
    ran 049 heads 2.065/1.88 valve, edelbrock performer intake, 600cfm edelbrock carb, headers MSD ignition, dual 3" exhaust
    cam was
    https://www.summitracing.com/oh/parts/sum-1300
    .050" 208*/218*
    LSA 112
    .475/.500
     
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  2. Fez_Jet_Az

    Fez_Jet_Az Newbie

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    http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=589&sb=0

    I just fired my engine last week with the above cam and its great. It is mannered much like stock with idle quality and vacuum. Passed AZ roller emissions with the factory exhaust as clean as a whistle.

    In all fairness i have not loaded up and towed on the interstate with it yet, but it does pull at idle my camper at 10k lbs. I also put the pedal to the ground with the camper hooked up and there is plenty more get up than there was factory in first gear, now this was just taking it in and out of storage at the lake so I couldn't get too crazy.

    Putting the pedal to the truck through the gears on the street has really impressed me, your at 100mph in a blink and it pulls steady building power through 5k rpm shift points, there is ample power on tap all over the rpm band.

    I went with the Comp kit for this cam install on a fresh engine build. If you go that do note that the timing set that comes in the kit will not work with the reluctor wheel that the crank position sensor reads, Jegs was generous enough to refund me the cost of the timing set. Also you will need valve spring rotator eliminators which are not included in the kit. Another surprise per say was larger 3/8 pushrods which require additional purchase of GM performance #12562369 guide plates, my factory L29 is 5/16. Rockers were not included in kit but I went with Comp Magnum roller tip as they do not deflect like the factory units do.

    I will say that aggressive lobes on the comp cam combined with the roller tip rockers generates a fair amount of valve train noise that depending on the individual might be considered as annoying at idle. That combined with the fairly obnoxious noise that the injectors I used make has led me to open my valve covers a couple times just to do a wellness check on the valve-train. But at this point I am over it and its confirmed all is good, just be aware. I have delayed my header install as to not introduce additional noise under the hood, but next week the cam gets to breath through headers and full exhaust, and that should be real exciting.....

    In hind sight if I had it to do over again I would have gone with cam in the link below, its the same lobes but ground on a 110lsa and 4 degrees advance VS the cam in my engine that is ground on a 113lsa with 2 degrees advance.

    I assume that the characteristics on a 110lsa would be tame enough for what I do with my truck and still pass emissions, but that is an assumption based on how docile the manners of the cam are now in the motor on the 113lsa.

    Black Bear Performance delivered me a mail order tune for my ancient 97 black box computer.

    http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=579&sb=0


     
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