Cam Selection and Comparison

Discussion in 'Street/strip 400/430/455' started by knucklebusted, Jan 25, 2013.

  1. knucklebusted

    knucklebusted Well-Known Member

    The question is: Will I tell a difference in a 455 with a Comp Cam 268 and a TA212 and is this the best choice for my new street cruiser motor?

    The details:

    My current motor has a Comp Cams 268 cam I bought back in the early 80s. It is from back before they were High Energy and while I do not have the cam card, I do remember it being symmetric and having only .454 lift. Current 268H cams have .468 lift. It runs in a stock 70 block and pistons, small valve heads, MT Repro headeers and an Edelbrock intake. Basically just a mild street motor that sounds decent. It idles with just the slightest hint of a lope at 700 but cleans up completely by 1,000. Pulls good up past 5,000 but runs out of juice by 6,000. I originally was just going to bolt the Edelbrock heads to this motor and drive it another dozen years until I ran up on a decent short block deal.

    My new motor has a TA212 that is advertised at in:.473 and ex:.485 with 1.6 rockers with power between 1,500 - 5,500 and a good idle (mild lump, doesn't impair drivability).

    The new motor is built with forged TRW pistons about .035 down in the hole, .030 over and box-stock Edelbrock heads and intake. The board member I bought it off of said it has tight clearances, between .0015 and .002 on the rods and crank. I don't really plan on spinning it to 6,000 very often and probably will not race much if at all but I do like to hear it roar. The car is non-air, low options 70 Stage 1 car. I've got a turbo 200-4r with a 2,300 lock up stall and 3.73 rear.

    I'm mostly looking for a gut check before I start buttoning it up. The idea of a roller sounds awesome but I don't want to go wild. I want it reliable, as in power tour reliable.

    Bonus question: What other less obvious things should I be considering?
     
  2. bostongsx

    bostongsx Platinum Level Contributor

    I would check the clearances, its tighter than I would run. Also consider an sp1 cam, just had great results with a comparable short block and mild stage 1 heads.
     
  3. pmuller9

    pmuller9 Well-Known Member

    You are going to see a bigger difference because of the change from stock heads to the Edelbrock heads.

    http://www.carcraft.com/techarticles/ccrp_0907_buick_455_cylinder_heads/

    The Comp cam is a 218/218 single pattern profile which has good low end power but falls off at the high end because the exhaust duration is not extended to overcome the restrive (dog keg) exhaust ports.

    The TA212 with 218/230 has a 12 degree extended exhaust duration which increases the power band at the upper rpm range.

    Combine that with the better flowing Edelbrock head and you should see some good usable street power.

    I have a set of Edelbrock heads sitting here and I need to find a solution to the SBC roller rocker arms not being centered on the valve stem.
    The Buick rocker arms have an offset at the pushrod end but the SBC rockers do not.

    Paul
     
  4. TheSilverBuick

    TheSilverBuick In the Middle of No Where

    I've seen lots of small block chevy's with off set rocker arms :confused:

    ---------- Post added at 09:06 PM ---------- Previous post was at 08:54 PM ----------

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  5. pmuller9

    pmuller9 Well-Known Member

    I should have said "stud mount SBC rockers for use with the Edelbrock heads"

    I've seen SBC shaft mounted pairs that are stud mounted but I'm sure they do not have the same spacing as the BBB Edelbrock head studs.
    I haven't taken the time to investigate any of this yet.
    There are 2 other engines we are trying to get finished first.

    Paul
     
  6. 300sbb_overkill

    300sbb_overkill WWG1WGA. MAGA

  7. pmuller9

    pmuller9 Well-Known Member

    I wont know how much offset will be needed till I get the cam and lifters in and can set the heads on.
    It will be a few weeks till the block comes back from our machinist.

    Thanks for the links. There are some possibilities there.

    Paul
     
  8. 300sbb_overkill

    300sbb_overkill WWG1WGA. MAGA

    Anytime Paul,you help so many people here,just thought I would try to help the helper.

    When you figure it out,let us know,thanks.




    Derek
     
  9. knucklebusted

    knucklebusted Well-Known Member

    I was planning on running 5W30 in it so those clearances should be good, right? It will see more cruising than hard pulls but a few blasts are going to happen. I don't have any self control of my right foot. What is an SP1 cam? I'm only familiar with the SP1 as a intake.

    Excellent! That's what I was hoping to hear. The builder of the short block, a board member, was attempting to replicate the first story of that 455 build. I, apparently, am attempting to replicate the second article.

    What is the deal with the offset rockers? Is that necessary for all or just the upper RPM motors? I plan on seeing a max of 6,000 (MSD 6AL chip) and would shift most times at 5,200-5,500.

    Good info.
     
  10. TheSilverBuick

    TheSilverBuick In the Middle of No Where


    Ah yes, can't say I have seen offsets on the stud mounted ones. I figured when you said you hadn't seen anything with an offset pushrod I figured I was missing some part of the puzzle.
     
  11. pmuller9

    pmuller9 Well-Known Member

  12. TheSilverBuick

    TheSilverBuick In the Middle of No Where

    Well at least I'm consistent, lol.
     

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