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  1. #1
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    Anyone have experience with single pattern cams?

    Was pretty set on a 210/220 .544/.544 112lsa cam until I spoke to Brian at IMM. He recommended a 212/212 .563/.563 112lsa cam even though I have a single 3" exhaust with a cat. Said I'd be giving up TQ with the 210 cam and I would have p2v clearance with the stock short block and .028 gaskets but don't quote me on those lift numbers.

    I didn't bug him too much because I'm sure he was busy but I'd love to learn more on this topic. The man is a successful engine builder/porter so I'm leaning more to his cam versus what I've been reading online. If I went with a 110 lsa I'd be at -8 overlap versus -12 he recommended. The 210 cam would have been -5 at 110 and -9 at 112. I think -4 is about the max you can run with any hopes of passing the sniffer. Shouldn't I benefit more from the 110lsa on 212/212 cam? Thanks!

    Camquest says:
    424hp/430tq peak with 131hp/169tq avg with 210/220 112lsa 112icl.
    409hp/426tq peak with 115hp/157tq avg with 212/212 112lsa 112icl.
    about 5hp/tq peak higher with 110lsa 110icl averages about the same as 112.
    Last edited by THEhomelessONE; 03-08-2017 at 08:47 PM.

  2. #2
    RallyJeep GO
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    It depends on the setup. If the exhaust ports in the heads flow well enough relative to the intake and you're running good flowing headers with a good exhaust, a single pattern can work well. If the exhaust flow is lacking a bit, a dual pattern can sometimes make more power.

    As a middle ground, what numbers do you get for a 212/218 setup?

    Brian definitely puts out some good work, so his thoughts are certainly worth looking at. I've been very happy with the heads I got from IMM.
    1998 ZJ 5.9 Limited - Deep Slate
    Mods: Big trans cooler, 231 swap, Indy MA-X heads prepped by IMM, Comp 20-744-9 cam, 1.7 HS roller rockers, 52mm TB, Airgap manifold, DT headers and full 3" exhaust, SCT tune homebrewed by me, Martin Saine valve body, B&M tranny pan, magic suspension made from unicorn tears, power steering cooler, lots of lighting mods

  3. #3
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    Yeah his heads have about a 72% ratio. I tried a bunch of combos up to about 230 duration cams and nothing is really beating the 210/220. I think maybe Brian is recommending the 212/212 cam is for part throttle response and driving around town/highway? Since we can't really use much under 2500rpm at WOT with our autos. So similar top end to the 210/220 cam but with stronger DD characteristics. Just guessing here lol.

    Having a single 3" exhaust with cat really bugs me knowing most of the stuff I read online is for dual exhaust setups.

  4. #4
    RallyJeep GO
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    A single exhaust isn't a big deal, although ideally a single 3.5" from the y-pipe back would be better sized for that power level.

    The 212/212 should make a little more low end than the 210/220, as it'll bleed off a little less compression. Of course, it depends on the ramp rates of the cam (can tell by comparing their advertised durations).

    My setup is running the tiny little baby cam with 6* of split (206/212, .512" lift at the valves with 1.7s). But it does have a very nice, wide powerband. And it pulls well up top too. I figure it should be good for 370 - 380 hp at the crank once I get the 4bbl TB on to un-cork things a bit. Might need to open up the exhaust a little more to hit that target though.

    If you were in the right part of the world, I'd say I'll take you for a drive in mine as a point of reference.
    Last edited by comptiger5000; 03-09-2017 at 05:37 PM.
    1998 ZJ 5.9 Limited - Deep Slate
    Mods: Big trans cooler, 231 swap, Indy MA-X heads prepped by IMM, Comp 20-744-9 cam, 1.7 HS roller rockers, 52mm TB, Airgap manifold, DT headers and full 3" exhaust, SCT tune homebrewed by me, Martin Saine valve body, B&M tranny pan, magic suspension made from unicorn tears, power steering cooler, lots of lighting mods

  5. #5
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    Read somewhere than since the piston is forcing the exhaust out versus trying to draw it in, it's better to go with a single pattern as long as head flow isn't too restrictive. Makes sense to me lol I'll go with what Brian says.

    Brian recommended 112 lsa but isn't a tighter LSA better? 112 lsa would give me -12 overlap and 110 lsa -8. 108 lsa would give me -4 overlap but that's cutting it too close.

    Oregon cams have some good reviews and pricing similar to comp. Bullet is just over $400. Hipotek right in the middle. Not sure who else to look into.

    Curious why you want to go with a 4bbl vs 58mm? How high do you spin your niner? Glad to hear you're happy with the top end. Thanks for the drive offer! Lol I'll post up my dyno results, thanks again for all the help man I've learned a ton from you!

  6. #6
    RallyJeep GO
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    Tighter LSA might make a little more peak power, but it'll have a rougher idle and a narrower powerband. You do need less exhaust flow than intake flow as the exhaust is leaving under pressure. But that's most of why the head flow numbers are more on the intake side. As long as your exhaust downstream of the heads isn't too restrictive, yeah, the single pattern will be fine. IMO, the huge split dual patterns (like the 210/220) are mostly for stock exhaust manifolds and other restrictive exhausts. Otherwise, a smaller split or a single pattern is probably better.

    On mine, power starts to fall off after 5500 or so, but the drop is pretty slow. Shift points are set to 5800, rev limiter is 6k.

    I got the 4bbl for $200 and the airgap will take a 4bbl, so I'd rather do that and figure out a solution for mounting the cables, etc. than spend $500 on a 58mm.
    1998 ZJ 5.9 Limited - Deep Slate
    Mods: Big trans cooler, 231 swap, Indy MA-X heads prepped by IMM, Comp 20-744-9 cam, 1.7 HS roller rockers, 52mm TB, Airgap manifold, DT headers and full 3" exhaust, SCT tune homebrewed by me, Martin Saine valve body, B&M tranny pan, magic suspension made from unicorn tears, power steering cooler, lots of lighting mods

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