What’s the biggest cam a stock appearing

Discussion in 'Stock Appearing' started by wildcat4, Nov 23, 2019.

  1. wildcat4

    wildcat4 Well-Known Member

    I am trying to go from headers back to manifolds and I wonder what’s the biggest cam a guy can use when running through the little 2 1/4” hole.
    My 455 has ported stage 1 heads
    10:8 compression (if I remember correctly)

    Thanks for some help
    Rob
     
  2. David Hemker

    David Hemker Well-Known Member

    It's all in the combo. I've seen what is considered very large cams used and I've seen extremely small cams used. You will want to use a large spread dual pattern cam like the factory did to compensate for the less than stellar exhaust flow inherent to the Buick exhaust ports and manifolds. Having head flow data available is important. Matching the torque convertor to the combo is critical. Your exhaust manifolds must have been worked on to get to 2 1/4".
     
    SpecialWagon65 likes this.
  3. wildcat4

    wildcat4 Well-Known Member

    Yes the manifolds were worked on.
    I guess I will just have to try a cam and see if it improves any or not. With no flow numbers on the heads I can only guess. When Gessler ported the heads he suggested 500 to 560 lift max. Currently the engine has a .520 lift 298-298 cam with 21* overlap.
    I assume this is too much but wondered if anyone has seen that work.
     
  4. David Hemker

    David Hemker Well-Known Member

    Do you know the .050 duration specs for the cam that you are using?
    Will you be using street tires or sticky's at the track?
    What stall convertor will you be using?
     
  5. wildcat4

    wildcat4 Well-Known Member

    I want to use the TA 310 cam which I have on the shelf but I don’t have the cam card for it,
    Just hoping I could get by with it.
    I guess I could get those specs by sticking it in a spare block and check it manually.
    32-3500 and a 3:90 gear. I will be using drag radials.
    My car is loaded and weighs 4020 going down the track. It’s not going to break any records but I enjoy it.
     
  6. pbr400

    pbr400 68GS400

    I’m running the 290/94; it’s a little milder (split duration on a 112) and it drives really well. I have 2.93 gears and less stall than you and it ran bottom 13s on slicks. (Hoping with a little more driving it’ll sneak into the 12s). The 310 is a single pattern; I think with manifolds you’d be better off with a split duration.
    Patrick
     
  7. wildcat4

    wildcat4 Well-Known Member

    Right, from what I am learning that is probably what I will have to buy.
    Your car must cruise down the highway without even trying.
     
  8. pbr400

    pbr400 68GS400

    I haven’t been on the interstate with it yet, but driving around town and on country roads it’s really nice. The 455 that was there was very mild and ran high 13s with a stock converter; I drove it regularly and commuted to Atlanta with it fairly frequently. The current engine has more compression, mildly ported Stage 1 heads along with the cam and converter (Hughes GM20BPO). It definitely doesn’t sound stock and seems to drink faster but it now has plenty of power for safe merging and passing. I’d love to see your ‘Cat run BSA in May! Pick Dave Hemker’s brain about your combo. He knows a thing or two, as do Starc Traxler and Bryan Woodworth. Check the BSA threads for more info.
    Patrick
     
  9. wildcat4

    wildcat4 Well-Known Member

    Awesome
    I need all the help I can get. I have been searching through some older threads and learning here and there.
     
  10. wildcat4

    wildcat4 Well-Known Member

    And yes this is all based on getting me into BSA in May
     
  11. UNDERDOG350

    UNDERDOG350 350 Buick purestock racer

    I've had good results with Crower cams with wide centerlines in the 350 with iron manifolds. I'll bet they work well in big blocks also. You really want a little more lift and duration on the exhaust side.
    Look at PN 52240
    HIGH PERFORMANCE COMPU-PRO / Performance Level 3
    Intended for the hot street application, these cams offer extended rpm range with emphasis on upper
    bottom and top end power. RPM Power Range: 1800 to 4500 / Redline: 5000 Plus.
    280/286 duration, .488..498 lift on 112 lobe sep.
    Anything much more than that will be choked by the manifolds.
    Mr Hemker has custom grinds made that work very well.
     
    wildcat4 likes this.

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