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Roller cams in BBC?

Discussion in 'The Garage' started by Sparky87k5, Jun 28, 2003.

  1. Sparky87k5

    Sparky87k5 1/2 ton status

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    Looking at installing a roller cam in my 427 in pursuit of more low-end torque. Running a 270/280 duration (218/228 @ .050 lift) .500 lift GM Marine cam advanced 4* at present but think a roller might do a better job for me. Been looking at the Comp Cam Xtreme Energy XR258HR cam with 258/264 duration (206/212 @ .050 lift) .510 lift for better torque down low (2400) Like to see peak torque around 3000-3200. Anyone ever run a roller in a BBC. How much work to convert older model BBC’s to roller cam? Better cams out there? Worth it?
     
  2. dyeager535

    dyeager535 1 ton status Premium Member

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    Doesn't installing the cam advanced hurt low end but improve upper end?

    I'm sure others will chime in, but straight up is pretty much the best you can do if you want the best of both worlds as I understand it. Or more correctly, decent on either end of the scale.
     
  3. Sparky87k5

    Sparky87k5 1/2 ton status

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    Advancing a cam 4* increases the low-end torque and shifts the horsepower curve lower in the RPM range. You don't generally gain a lot of torque or horsepower but rather shift it to a lower RPM. As an example, my 427 has peak torque of 428 ft lbs. @ 3500 with the cam advanced 4*, but 427 ft.lbs. at 4000 straight up. At straight up it only has 417 ft.lbs at 3500. Advancing it was worth 11 ft.lbs. and as a by product about a 5-6% increase in fuel mileage.
     
  4. nvrenuf

    nvrenuf NONE shall pass! Premium Member

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    There's nothing special about putting a roller in a bbc you just have to buy a lot of parts. You'll need the cam, lifters, push rods, rocker arms and springs - about $800~$1000 for everything.

    I used to run a solid roller cam in my 454. I liked it a lot but I didn't like the frequent adjustment. If I had it to do over I would but I'd get a hydraulic set up for obvious reasons. The biggest benefit of the roller design is the fact that you can run cam profiles that are not achievable with a flat tappet style. With that in mind, plus the cost I would be sure to buy something that was definitely not similar to an off the shelf flat tappet cam.

    I really liked the one I ran, when it reached it's power band it pulled REAL HARD but mine had a fairly aggressive profile. /forums/images/graemlins/cool.gif
     

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