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Lumpy Cams

Discussion in 'The Hokey Ass Message Board' started by oldeman, Sep 16, 2008.

  1. oldeman
    Joined: Aug 17, 2008
    Posts: 13

    oldeman
    Member
    from Ms

    Hello Board:Is it possible to have a lumpy cam in a 8.1 comp motor without a lot of problems? I have a stock 403ci olds thats going into my 33 olds,would really love to hear that sound that only a lumpy cam can bring.Maybe I'am just dreaming. Anyway. Thanks In Advance

    Oldeman
     
  2. jagfxr1949
    Joined: Jun 27, 2008
    Posts: 277

    jagfxr1949
    Member

    Ran a 300H Monarch years ago in a 9 to 1 SBF - cool sound - absolutly NO bottom end. Compression helps with the low RPM torque. Lumpy cam blows off a lot of compression at low RPM so with 8 to 1 there will not be much there and might be tough to drive. I love lumpy cams though.
     
  3. Ebbsspeed
    Joined: Nov 11, 2005
    Posts: 6,441

    Ebbsspeed
    ALLIANCE MEMBER

    Well, yes, you can. But that's about the only thing you'll have is a lumpy sounding motor. In order to work well, a motor needs to have components that compliment each other. Compression, induction, valvetrain, exhaust, ignition, etc need to have some semblance of "matching" in order for a motor to do more than just make a lumpy sound. But if that's all you're after, go for it.
     
  4. squirrel
    Joined: Sep 23, 2004
    Posts: 59,180

    squirrel
    Member

    The rest of the drivetrain is probably more important than the compression ratio, when it comes to cam selection. Look at the RPM range of the cam you want to run, and decide if you're willing to run the torque converter and rearend gear necessary. Also think about if the induction/heads/exhuast will work well at that rpm range.

    If you put a long duration cam in an otherwise stock car, you lose the bottom end torque, but you also strangle the top end performance, so you have a really bad performing ride.
     
  5. 50Fraud
    Joined: May 6, 2001
    Posts: 10,099

    50Fraud
    Member Emeritus

    Somebody I knew told a cam grinder that he wanted a cam with a wild idle. He said he wasn't all that concerned about power or RPM, but he wanted the nasty sound.

    The cam grinder said, "Oh, just like everybody else."

    Has anybody tried one of Comp Cams' "Thumpr" grinds? According to their ads, they are exactly what you're asking for -- a wild idle with reasonable performance and driveability.
     
  6. Trent_A
    Joined: Feb 12, 2007
    Posts: 96

    Trent_A
    Member

  7. Dyce
    Joined: Sep 12, 2006
    Posts: 1,980

    Dyce
    Member

    Look in the circle track grinds. There are cam grinds suited for classes with a compression limit. If I remember right they close the exhaust sooner, and increase cylinder pressure by keeping a little exhaust in the cylinder. Squirrel is right. The convertor and gears are a must, or a manual trans.
     
  8. BigThree
    Joined: May 3, 2006
    Posts: 120

    BigThree
    Member

    All cams are lumpy! :D

    Sorry, I'm just a smart-ass.
     
  9. 3Mike6
    Joined: Jan 2, 2007
    Posts: 704

    3Mike6
    Member

    Lumpy is nice, if you have the rest of the engine to support it...otherwise just get one of the fancy rev limiters that drop different cylinder at a time, and turn it way down when your parked.
     
  10. Try a comp cams XE274H. I have had the best luck with the Extreme Energy series cams. As long as you have good ring seal and a tight valve job, to keep the compression in the cylinder, you'll be fine. By the way wasn't Lumpy a dude on Leave It To Beaver??? >>>>.
     
  11. From reading your question it looks like all you want is that "Lumpy powerful" sound. That comes from lots of overlap and a motor with low compression will not sound "Powerful" at all, more like mushy and like its miss firing. Nothing sound better than the pop of a high compression motor with a big cam, but I don't think you'll get that.
     
  12. panic
    Joined: Jan 3, 2004
    Posts: 1,450

    panic

    1. cross the 5 and 7 plug wires
    2. leave a vacuum hose off
    3. Ta-Da!!
     
  13. Install a manual choke and run it 3/4's shut TA/DA >>>>. And by the way Lumpy's last name was Rutherford >>>>.
     
  14. panic
    Joined: Jan 3, 2004
    Posts: 1,450

    panic

    What reduces low speed power: late intake valve closing
    What makes that rilly kewl idle: high overlap
    Not the same thing
    When does leaving exhaust gas in increase pressure: never
     
  15. dana barlow
    Joined: May 30, 2006
    Posts: 5,368

    dana barlow
    Member
    from Miami Fla.
    1. Y-blocks

    In the 50's, when Ya was stuck with Dad's car,cus your rod was broke,to make the run to da car hop drive-in hangout on fridays or sat. nite ,ta see your bud's and make that car sound like it had a sleeper mill hinding under the hood,we took off the air cleaner so it made lots of carb sound and pulled the choke out tell it sounded lumpy,fooled some:D ;)
     
  16. oldeman
    Joined: Aug 17, 2008
    Posts: 13

    oldeman
    Member
    from Ms

    Thanks Guys:I think that I maybe knew better but wishful thinking you know.SOooo 403 will be coming apart for a bet of a bore,decking.highing comp. piston And that Lumpy cam.I really can't afford any of this,but lumpy cams RULE.Thanks again Guys.

    oldeman
     
  17. Thumper
    Joined: Mar 7, 2005
    Posts: 1,610

    Thumper
    Member

  18. Yeah and Lumpy had a cool 40 Ford in Grey Suede in one episode! Got arrested in it when Beav thought they were burglars. (was on TV Land a couple weeks ago)
     
  19. no55mad
    Joined: Dec 15, 2006
    Posts: 1,972

    no55mad
    Member

    My high school buddy did this to his dad's olds 455 and dropped the air cleaner wing nut down the carb. It went down the intake and stuck the valve open - busted:eek:
     
  20. Dyce
    Joined: Sep 12, 2006
    Posts: 1,980

    Dyce
    Member

  21. nexxussian
    Joined: Mar 14, 2007
    Posts: 3,237

    nexxussian
    Member

    Probably not what you're looking for (and NOT cheap) but with the compression that low an Isky 5 cycle and a blower would 'sound' cool.
     
  22. spoons
    Joined: Jan 1, 2004
    Posts: 1,738

    spoons
    Member
    from ohio

    send it out and have it reground....Clay Smith does it. Had a buddie have his 276 (HEMI) reground and it sounds bitchin w/ 7.5-1 compression.....
     
  23. crowerglide
    Joined: Aug 31, 2006
    Posts: 201

    crowerglide
    Member
    from Tyler, TX

    That's what I heard. Sounded like there might have been a tractor idling off in the distance, too.:D
     
  24. ...HOWEVER...a lumpy cam with a set of Flow Masters is "THE" sound...
     

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