455 Stage 2

Discussion in 'Street/strip 400/430/455' started by RondoBoi, Jun 25, 2019.

  1. 436'd Skylark

    436'd Skylark Sweet Fancy Moses!!!!!

    Perhaps the 1.43 is a typo.. that's insane for a 107 trap.
     
  2. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    Just going by the piston description from TA, modified compression height and 20cc dish. Not sure if it is 0 deck. Have to wait for more details from the OP.
     
  3. BQUICK

    BQUICK Gold Level Contributor

    Sounds like 42deg timing not 24....that would make it leave real hard but then detonate and not run on top end.
    Helped a guy at the track many years ago with a built 455....he had just turned the timing up to where it idled well with 107 KB cam....fortunately caught it before making more passes.....
     
  4. TORQUED455

    TORQUED455 Well-Known Member

    My best 60’ times were 1.50 in the convertible. That was with slicks and front wheels off the ground. I don’t think the OP’s cam timing can be off if indeed his 60’ time was 1.43, which doesn't seem plausible. Where are ya, OP?
     
  5. GraySky

    GraySky Well-Known Member

    If it was far advanced it would have massive low-end torque, and it would kill the top end, and would tend to detonate because of the intake closing point being advanced.
     
  6. Philip66

    Philip66 Well-Known Member

    OP hasn't been seen since about an hour after he made this post.
     
  7. Bens99gtp

    Bens99gtp Well-Known Member

    Maybe they don't need help after all?
     
  8. RondoBoi

    RondoBoi Member

    you are correct. happy fingers on the 1.43 60ft. it was 1.73. sorry for the confusion.
     
  9. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    Hey, that's a 4-7 swap.:D:D
     
    johnriv67 likes this.
  10. 436'd Skylark

    436'd Skylark Sweet Fancy Moses!!!!!

    You clever bastard.
     
    johnriv67 and LARRY70GS like this.
  11. No Lift

    No Lift Platinum Level Contributor

    The 60' sounds like it is in line for the ET/MPH. However those engine specs sound like it is just plain down on power as said. Get rid of ping and power will come up.

    Is it still pinging? What MSD box are you talking about? 24* in the box? Is it a digital box where you dial in your curve? Maybe 24* in the distributer plus initial? I agree with checking the timing mark on the damper. That can easily be done with a piston stop and some tape and a marker. Measure at one end of the stop, mark damper, bring it around to other end of stop, mark damper, figure out where the middle is and you have TDC. Should be at the mark in damper.

    What is your cranking compression? Anything over 200 lbs with aluminum heads could get touchy although it would be tough to get much over 11:1 with nominally milled heads and zero deck. I think I'm just under 64cc TA Stage 1's and zero deck and I believe it is right around 10.9:1 with no ping problem. Cranks around 200 IIRC.

    The idea that the cam is way over-advanced is a good possibility. With 248*I/254*E/110*LSA , 31* overlap @.050" that cam should be keeping the ping at bay(slightly bigger than my hydraulic roller's 242/248). Where the intake is opening can be checked with just a dial indicator after the damper mark is confirmed to be correct. Take all plugs out and the driver side rocker arms off. Check where the .050" lift opeing point is with the indicator. Installed at typical +4* the intake opening should be at 18* BTDC which is just off the scale of usual timing cover's 14* BTDC. It would be easy to measure it with a ruler at that point to confirm where it is at, the distance of two of the lines. It would be at 14* BTDC if it was straight up. However, it is a solid cam so those numbers may be skewed by a few degrees but I would say the spot should have slightly less advance than I've specified, say 12* BTDC, maybe? If you are anywhere in that range then the cam is probably close to where it belongs. Anything less is ok but anything more past the scale is trouble.
     

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