Installing Custom Roller Cam per FABO reccomendations

Discussion in 'Small Block Mopar Engine' started by bschubarg, Jun 9, 2018.

  1. bschubarg

    bschubarg FABO Gold Member FABO Gold Member

    Messages:
    287
    Likes Received:
    107
    Joined:
    Jun 13, 2005
    Local Time:
    10:18 PM
    The current 318 standard bore with ported #302s has the Comp Cams 20-212-2 Flat Tappet.

    Lobe Sep: 110*
    268*/268* Adv.
    218*218* @.050
    .454/.454 Lift

    59* degrees overlap.

    Best cylinder pressure is 130 psi.
    Using the Wallace Calc I get a V/P of 98..... Horrible.


    New Cam:
    Custom Roller 111.5 Lobe Separation
    214*/214* @ .050
    .474/.474 Lift

    38.8* degrees overlap

    Wallace V/P Dynamic Calc resolves V/P to 131.... better.

    But this is all just on paper. I know how the Comp Cams run in my '87 Chrysler Fifth.
    After install this weekend I will give you my impressions of the new custom Roller with 30+ V/P Index.

    Ought to be interesting.
     
    • Like Like x 5
    • nm9stheham

      nm9stheham Well-Known Member

      Messages:
      9,031
      Likes Received:
      1731
      Joined:
      Dec 20, 2013
      Location:
      Waynesboro, VA
      Local Time:
      10:18 PM
      This is with the super low rear axle ratio, right? Yes, ought to be interesting.

      Where are you timing the ICL on the new cam?
       
    • bschubarg

      bschubarg FABO Gold Member FABO Gold Member

      Messages:
      287
      Likes Received:
      107
      Joined:
      Jun 13, 2005
      Local Time:
      10:18 PM
      2.21 Rear and all I'm doing is advance the cam 4* degrees....Yes, it will be interesting. If I can light up the tires from a stand still, then for me it is a win....
       
    • bschubarg

      bschubarg FABO Gold Member FABO Gold Member

      Messages:
      287
      Likes Received:
      107
      Joined:
      Jun 13, 2005
      Local Time:
      10:18 PM
      cam2.jpg Comp Cams 212-20-2 after 12K...
      2018-06-09 16.21.14 (1).jpg 2018-06-09 16.21.14 (1).jpg cam2.jpg 2018-06-09 16.21.14 (1).jpg

      cam.jpg
       
      • Like Like x 1
      • gliderider06

        gliderider06 Well-Known Member

        Messages:
        1,011
        Likes Received:
        118
        Joined:
        Oct 21, 2011
        Location:
        Delaware
        View My Photos
        Local Time:
        10:18 PM
        Jim at Racer Brown will custom grind a cam for you that will out perform any out of the box cam any day of the week.
         
        • Agree Agree x 1
        • RustyRatRod

          RustyRatRod Just another dumbass. Technical Editor

          Messages:
          46,193
          Likes Received:
          10563
          Joined:
          Jun 7, 2010
          Location:
          Georgia
          View My Photos
          Local Time:
          10:18 PM
          You could stand to advance that cam down around 103. Jes sayin.
           
        • BigBlockMopar

          BigBlockMopar BigBlockMember

          Messages:
          1,497
          Likes Received:
          452
          Joined:
          May 1, 2011
          Location:
          Netherlands
          Local Time:
          4:18 AM
          gliderider,
          He just got a new custom roller cam and you're advising him to call someone to grind him another new custom roller cam?
           
        • gliderider06

          gliderider06 Well-Known Member

          Messages:
          1,011
          Likes Received:
          118
          Joined:
          Oct 21, 2011
          Location:
          Delaware
          View My Photos
          Local Time:
          10:18 PM
          Sorry, I misread his post. Somehow I read that he was thinking of getting this cam and these were the numbers on paper. Sorry for my confusion.
           
        • bschubarg

          bschubarg FABO Gold Member FABO Gold Member

          Messages:
          287
          Likes Received:
          107
          Joined:
          Jun 13, 2005
          Local Time:
          10:18 PM
          No worries glider...like you, everyone told me to get a custom grind and that is exactly what I did... hopefully installation will be completed today.....
           
          • Like Like x 1
          • Wyrmrider

            Wyrmrider Well-Known Member

            Messages:
            822
            Likes Received:
            246
            Joined:
            Sep 5, 2016
            Location:
            los angeles
            Local Time:
            7:18 PM
             
          • Wyrmrider

            Wyrmrider Well-Known Member

            Messages:
            822
            Likes Received:
            246
            Joined:
            Sep 5, 2016
            Location:
            los angeles
            Local Time:
            7:18 PM
            true of shelf chevy grinds, not true for modern grinds unless Racer is channeling new profiles
            No Ultradyne hyd profiles from Harold either
             
          • yellow rose

            yellow rose Doctor of Thinkology.

            Messages:
            15,415
            Likes Received:
            11996
            Joined:
            Jun 19, 2015
            Location:
            Living on the razors edge
            Local Time:
            7:18 PM

            Jim has many new lobes. You have to ASK him about them. He won't sell you a new lobe for a head and intake system that is 50 years old.

            90% of the guys out there won't know the difference. Especially in a street car. Much ado about nothing when it comes to lifter diameter.
             
          • Wyrmrider

            Wyrmrider Well-Known Member

            Messages:
            822
            Likes Received:
            246
            Joined:
            Sep 5, 2016
            Location:
            los angeles
            Local Time:
            7:18 PM
            your opinion does not pass the math test YR
             
          • yellow rose

            yellow rose Doctor of Thinkology.

            Messages:
            15,415
            Likes Received:
            11996
            Joined:
            Jun 19, 2015
            Location:
            Living on the razors edge
            Local Time:
            7:18 PM

            What math test? It's borderline idiotic to tell everyone if you don't run a lobe designed for a .904 lifter you are wasting your time.

            I'd bet my bottom dollar if I called Mike Jones right now to order a cam for my street/strip car he'd spec lobes from an .842 lifter. I know, because he did.

            So would you argue with Mike about using the wrong lobe and tell him his math is off?
             
            • Like Like x 1
            • Agree Agree x 1
            • rigger3006

              rigger3006 Well-Known Member

              Messages:
              638
              Likes Received:
              122
              Joined:
              Aug 6, 2013
              Location:
              bc
              Local Time:
              9:18 PM
              im sad to say my cranking compression is 125 on my 360 with 284/484 mp cam, jim at racer brown suggested i go 220/ 450 on 110, i think i wll wait and go the higher compression route in the near future
               
            • nm9stheham

              nm9stheham Well-Known Member

              Messages:
              9,031
              Likes Received:
              1731
              Joined:
              Dec 20, 2013
              Location:
              Waynesboro, VA
              Local Time:
              10:18 PM
              Yep, rigger.... that higher CR gives a bigger duration cam more usable RPM range.

              As for the lifter diameter, I honestly don't know the answer. I find it interesting that Crane has had different sets of lobe profiles depending on the lifter diameter in their Master Catalog for a long time. There must be something to it. But I have looked at the .842 and .904 profile data a couple of times and never have been able to convince myself that that either has any great advantage. Seems like you can get fast or slow ramps with either. I need to sit down later and tabulate a whole slew of these profiles for a single advertised duration (like 270-ish) and see if there is a trend. I'll try to make that easy to put in a post and share.
               
            • Wyrmrider

              Wyrmrider Well-Known Member

              Messages:
              822
              Likes Received:
              246
              Joined:
              Sep 5, 2016
              Location:
              los angeles
              Local Time:
              7:18 PM
              Good move Rigger
              Mike only has one .904 lobe hyd as far as I know, and it's excellent but his solids are golden and his rollers cannot be beat
              and if you use a chevy cam- more to it than just the lifter- maybe I''ll post a thread
              nm
              Crane had the .904 lobes in the catalog but no shelf cams used them AFIK- use the Comp lobe catalog- it makes it easy as it also show intensity- you also need .200
               
            • nm9stheham

              nm9stheham Well-Known Member

              Messages:
              9,031
              Likes Received:
              1731
              Joined:
              Dec 20, 2013
              Location:
              Waynesboro, VA
              Local Time:
              10:18 PM
              Thanks wym. That is good to know... I noticed that the cam we used in my sons' 340 was a Z series which is listed as for a .842 min diameter lifter.... one of the 2 best of their profiles IMHO for around 268 adv duration for area under the curve for hyd flat profiles. Yes, on the .200" duration.... and I'll look at the Comp numbers too.

              FWIW
              Here are those Crane hyd flat lobe profiles for around 268-270 advertised duration. The .842 min dia looks to be a bit crisper down to the close of the valves, but they both have some slow and fast ramps. The H218/306 and H212/306 look to be the best of the bunch and don't strike me as being all that different. .904 profile actually looks slower around the 'tails' of the ramps but faster from .200" tappet lift to full lift. Of course, this is not conclusive as to all that COULD be done with one or the other, and things may change with different tappet types, mfr's, etc.
              Crane Hyd Flat Profiles 268.gif
               
            • Wyrmrider

              Wyrmrider Well-Known Member

              Messages:
              822
              Likes Received:
              246
              Joined:
              Sep 5, 2016
              Location:
              los angeles
              Local Time:
              7:18 PM
              you are better off with a slow .904 lifter profile than a fast .842
              are you looking at the online catalog
              for comp you have to look at the so called jeep profiles- there are all 4 of them
              remember crane advertised duration is at .004 and comp is at .006 so an identical crane using crane method shows longer duration- sometimes a lot on a slow lobe
              unfortunately Hughes does not give seat timing
              Cranes profiles date from the earlier valve spring era and do not pushthe envelope
              they are smooth- Like Engles the .904 will have more area under the curve- it does not try for maximum lift which would take different springs
               
              Last edited: Jun 12, 2018
              • Like Like x 1
              • Wyrmrider

                Wyrmrider Well-Known Member

                Messages:
                822
                Likes Received:
                246
                Joined:
                Sep 5, 2016
                Location:
                los angeles
                Local Time:
                7:18 PM
                a comparison using Mike Jones
                -------------1.6--1.5-lobe-@006 @.050
                Jones chev 462 434 289 256 200
                Jones Mopar 491 461 307 256 202
                showing difference in lift with similar seat and .050 timing

                Jones Mopar 491 461 307 256 @ 202

                jones ch .488 .458 305 272@ 216

                Jones ch 496 465 310 276@ 220
                showing how much more duration you have to use with an .842 to get similar lift as .906

                here's a 256 comp XE showing just the intake note the increased "intensity" over the above
                XE 256H .478 447 299 256/ 212/ 22 54in 68 20 ex IC 54.5
                4x4 5900 .488 .458 .305 250@ 205 122 @200 comp .904 shorter duration still more lift

                HM2063164A .506 .475 .316 252@ 206 126 Hughes

                4x4 2901 .498 .467 .311 254 209 126 @200 comparable comp .904 similar seat duration
                K-52HYD .489" .458" .305" 254° 209° Easy on the valvetrain Engle






                 
              • yellow rose

                yellow rose Doctor of Thinkology.

                Messages:
                15,415
                Likes Received:
                11996
                Joined:
                Jun 19, 2015
                Location:
                Living on the razors edge
                Local Time:
                7:18 PM

                Geezus.
                 
              • nm9stheham

                nm9stheham Well-Known Member

                Messages:
                9,031
                Likes Received:
                1731
                Joined:
                Dec 20, 2013
                Location:
                Waynesboro, VA
                Local Time:
                10:18 PM
                Yes that has been my impression.... and, while it is not the topic, I kinda like them for that reason. Less stress on the valvetrain and lower contract pressures on the lifters...... less problems for break-in IMHO. Easy for a moderate build.

                BTW, we have not heard from the OP? How is is going?
                 
              • Wyrmrider

                Wyrmrider Well-Known Member

                Messages:
                822
                Likes Received:
                246
                Joined:
                Sep 5, 2016
                Location:
                los angeles
                Local Time:
                7:18 PM
                YR
                what most cam tech guys miss is that chevy is a short rod motor and much more tolerant of intake close as it takes many more crank degrees to move the piston around BDC
                long rod engines are much more fussy
                Around TDC it's the other way around
                Chevy jerks the piston away from TDC much quicker than a long rod motor so they start opening the valve earlier to get it open when piston demand needs the flow
                the same degrees of overlap is not as big a deal on a short rod motor as a long rod motor
                etc
                using the same specs on a SBC or BBC as a SBM or BBM leaves performance (however you describe it) on the table
                what's the difference in torque that .030 lift and the implied increase in duration at .200 and area under the curve indicates?
                WE went through this drill with a major fleet and also with the San Jose Municipal Busses where we dropped the EGT by 800 degrees (propane) with cam optimizations while giving more power and fuel economy

                nm Engle is similar- good quality, good wear, easy over the nose (no little pointy chevy lobes) both have more area under the curve
                but both series of lobes are dated but we are not talking "heads up" requirements are we
                 
              • yellow rose

                yellow rose Doctor of Thinkology.

                Messages:
                15,415
                Likes Received:
                11996
                Joined:
                Jun 19, 2015
                Location:
                Living on the razors edge
                Local Time:
                7:18 PM


                I agree. My problem is actually getting lobes that are designed for a .904 lifter. And I'm not sure for most of what most guys are doing, that they'd see a benefit with a .904 lobe.

                I'd have to run through the Comp lobe listing and have a look because I don't remember many .904 lobes being under 235ish at .050 and its damn hard to convince some of these cam guys it's worth doing a .904 lobe.

                I still have all the cam specs from when I built my engine a few years back. Only one cam grinder gave me a .904 lobe. That was Jim at Racer Brown. And I had better than an hour on the phone going over the junk I run before he actually decided I wasn't nuts and that netting .600 lift was actually worth doing. If I would have accepted less lift, I would have most likely ended up with an .842 lobe...maybe .875 if I was lucky.

                Sometimes it's a matter of who you know, or who you can convince you aren't off your rocker. Jim was the only guy I talked to who was willing to go with that much lift for my engine.

                Maybe tomorrow I'll go over the Comp lobes and see how many .904 lobes are under 235@.050.
                 
              • Wyrmrider

                Wyrmrider Well-Known Member

                Messages:
                822
                Likes Received:
                246
                Joined:
                Sep 5, 2016
                Location:
                los angeles
                Local Time:
                7:18 PM
                The XE275HL hyd is the shortest easy to find
                the others (4) are used for AMC but no reason they could not be used on a Mopar core- they could even use Ford or Chevy profiles on the exhaust
                I'd really like to see a 270, 265, 260 etc
                It's just so easy to stick a mopar billet in the grinder and copy what is known to work in a SBC
                Lately we have had a rash of questions concerning 8:1 motors these can really be helped with a short cam
                but you need as much lift as possible between 70 -112 to get the cylinder filled
                their heads do not flow much better beyond a half inch lift so open, stay open, close and on the exhaust open late as low compression can benefit from working the charge longer- and a lot of overlap is not helpful especially with stock manifolds
                Lunati seems to be giving MOPAR the most support with shelf profiles, and Hughes which look like they have switched from profiles that look like Engle to profiles that look like Howards
                Being here in CA I have not used the back east grinders much but we did use General Kenetics for the Javelin as well as Engle (Where TRACO was fronting the R&D)
                cheers