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Thread: Olds 455 Cam Selection?

  1. #1
    i have an olds 455, 0.30 over TRW, all balanced, all oil mods have been done with C heads(big valve) street dominator intake, 900cfm holley etc..etc.. and i purchased a mondello jm-25-28 its 280/292 dur. .523 .544 lift 108 lode sep. and im looking for anyones opinion. is this too much cam?

  2. #2
    Wet Dream
    Way too much lift for stock rockers. The max lift you should go is no greater than .500

  3. #3
    Way to much duration for the rpm's that the olds motor run. Get some adjustable rocker arms for that lift.
    ? Did Mondello's recommend that cam?

  4. #4
    the rockers have been changed to a 1.6 roller tip.. no i couldnt get a hold of anybody at mondello and i was cramped for time so i just bought it.. if assembled like so will it even run worth sh@$?? thanks for the info guys i just want it to be right.. and cam suggestions??

  5. #5
    Is that advertised duration or .050 duration???

  6. #6
    Is that advertised duration or .050 duration???
    not sure the cam card reads as so
    intake: .523
    exhaust: .544
    duration: 280/292
    intake at .50 = 236
    exhaust = 248
    108 lobe sep.
    rpm 2000 - 6500

  7. #7
    No, that's just advertised. It's probably a little big for ya. Don't let it spin too high for long. I'd check your retainer to guide (seal) clearance inside the spring. They can get too close above .500 lift.
    Back when I was looking at Mondello's stuff, I always liked the looks of the JM-22-25-10. No reason to get a cam that goes to 6500 when the engine with come apart past 5500. I just bought a wimpy little Comp 280 for my 455 build.

  8. #8
    My 455 is topped with stock Ka heads and a Torker II intake. Compression probably in the 9:1 area.
    Has a Lunati Bracket Master II grind 00080 in it.
    Here's the spec:
    Advertised Duration IN/EX: 280/290
    Duration @.050 IN/EX: 214/224
    Gross Valve Lift IN/EX: .472"/.496"
    Lobe Sep Angle / Intake Ctr Line: 112/
    Valve Lash IN/EX: Hyd/Hyd
    RPM Range: 1800-4600

  9. #9
    That cam is probably to big for the flow potential of stock C heads but it will run. For future reference, don't buy crap from Mondello's, they are jack asses that just want your money and will not help you with anything. If you are interested in other more helpful Olds vendors, i can give you someone.
    You would be better off with a smaller cam that better fits those heads. Did you intall the cam yet?

  10. #10
    My 455 is topped with stock Ka heads and a Troker II intake. Compression probably in the 9:1 area.
    Heh-heh, the guy I got my manifold from kept calling it a Toker.

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