Thinking Hydraulic Roller Cam - Thoughts, what do I need to Know?

Discussion in 'Street/strip 400/430/455' started by hdpegscraper, Apr 27, 2017.

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  1. matt68gs400

    matt68gs400 Well-Known Member

    I know absolutely nothing about what was done to them. Only that the car has a small cam in it now.
     
    matt68gs400, Jul 29, 2017
    #21
  2. 8ad-f85

    8ad-f85 Well-Known Member

    I'm cautioning the OP of the likelihood of a full pressure valve spring compressing a hydraulic lifter (esp. new and not pumped up) and giving a completely misleading impression into the clay or whatever.
     
    8ad-f85, Jul 29, 2017
    #22
  3. LARRY70GS

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

    With the heads on, the best way is to use checker springs on the one cylinder. The valves only get close at certain points. I believe it gets closest on the exhaust stroke, the piston is moving up as the exhaust is starting to close. Matt, I think you are worrying about nothing. P/V clearance is more of a problem with bigger duration cams, and 0 deck. My aluminum heads have .040 milled off of them. I used them on my 1st motor with a KB 118 cam (228/246, .490/.490). It had speed pro forged pistons with NO valve reliefs, and they were .035 in the hole. There were no problems.
     
    LARRY70GS, Jul 30, 2017
    #23
    matt68gs400 likes this.
  4. 65Larkin

    65Larkin Well-Known Member

    [QUOTE="LARRY70GS, post View attachment 355921 [/QUOTE]

    I saw this in the catalogue and am wondering at what level a 4-7 swap is beneficial seeing as the core is the same price?
    Is intended RPM , Power level or manifold ( dual or open plenum) type the determining factor?
     
    65Larkin, Jul 31, 2017
    #24
  5. LARRY70GS

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

    I saw this in the catalogue and am wondering at what level a 4-7 swap is beneficial seeing as the core is the same price?
    Is intended RPM , Power level or manifold ( dual or open plenum) type the determining factor?[/QUOTE]

    None of that. Just Google 4-7 swap and read up on it. I didn't see any downsides to trying it. I'm sure it didn't hurt.

    Hot Rod says maybe, http://www.hotrod.com/articles/lunati-cams/
     
    Last edited: Jul 31, 2017
    LARRY70GS, Jul 31, 2017
    #25
  6. 8ad-f85

    8ad-f85 Well-Known Member

    Not going to see notable gains on any sort of a mild build. Shouldn't hurt anything though.
    I've done a few but didn't bother to test any difference.
    My reasons were to ease the loads on the crank for 700-1000hp builds.
    Unsure if it worked.
    There are some Buick intakes that have a couple of weak flowing runners.
    It would be prudent to be on top of that before considering a firing order swap.
     
    8ad-f85, Jul 31, 2017
    #26
  7. Jim Weise

    Jim Weise EFI/DIS 482

    The 4-7 swap is no longer available for the standard 455 cams. TA discontinued it in the latest run of cam cores, and made 3 differrent core sizes instead, to match the grind you doing better.

    No worries

    JW
     
    Jim Weise, Jul 31, 2017
    #27
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