Camshaft recommendation for my specific Slanty build?

Slant 6 Engines

  1. hellfirechrome

    hellfirechrome Well-Known Member

    Messages:
    341
    Likes Received:
    24
    Joined:
    Aug 7, 2009
    Location:
    Tahoe
    Local Time:
    4:21 AM
    Howdy! Looking for an experienced recommendation for my build. First, the hardware;

    1965 Plymouth Barracuda

    Stock reman Slant six 225:
    -Cliffy (not Offy!) Hyper-Pak
    -Edelbrock 1403 with small jets & fat rods (live at 6200ft so leaned out)
    -Stock exhaust manifold
    -2.5" mandrel exhaust/glasspack muffler
    -No PS or AC
    -Electronic ignition (Mopar chrome box)

    Driveline:
    -904 Automatic Stock
    -8 3/4" rear with 2.93/LSD
    -4 wheel disc brakes, manual Wilwood style master

    I'm looking for a midrange-RPM torque-centric cam, I have a vintage 13' camper trailer I'll be towing on occasion. Driving-wise, I prefer road course style driving power, not really drag/off the line. I plan on keeping the 2.93 for now, might go 3.55/3.73 down the line.

    Whose cam & what grind(s?) should I lean toward for my build? What's going to give the most CFM flow improvement with that Hyper-Pak and still be streetable? I don't run Power brakes so a drop in vacuum/lopey idle is fine. I'm hoping someone will be speaking from experience running a Hyper Pak and similar 4bbl on a stock block. I've got NO interest in grinding heads, porting, polishing or anything too involved right now. Cams are an afternoon project, wanna keep it that way :)

    Thanks in advance! Here's my baby, she's coming along nicely...

    Cuda.jpeg Slant.jpeg
     
    Last edited: Sep 4, 2020
    • Like Like x 1
    • Charrlie_S

      Charrlie_S Well-Known Member

      Messages:
      3,097
      Likes Received:
      925
      Joined:
      Oct 17, 2005
      Location:
      Silver Springs, FL
      Local Time:
      7:21 AM
      Actually your going the wrong way. Everything you are doing hurts torque. Wouldn't be so bad at a lower altitude. You really need to increase the compression ratio as the first mod. Almost any cam you install, will lower the effective (dynamic) compression ratio.
      PS: That is NOT an Offie intake manifold. Looks like a Clifford.
      PPS: Nice looking ride
       
      • Agree Agree x 1
      • hellfirechrome

        hellfirechrome Well-Known Member

        Messages:
        341
        Likes Received:
        24
        Joined:
        Aug 7, 2009
        Location:
        Tahoe
        Local Time:
        4:21 AM
        Maybe I need a Torqstorm... ;)
         
        • Agree Agree x 1
        • Charrlie_S

          Charrlie_S Well-Known Member

          Messages:
          3,097
          Likes Received:
          925
          Joined:
          Oct 17, 2005
          Location:
          Silver Springs, FL
          Local Time:
          7:21 AM
          That should work
           
        • 65 Cuda 340

          65 Cuda 340 FABO Gold Member FABO Gold Member

          Messages:
          228
          Likes Received:
          242
          Joined:
          Dec 27, 2019
          Location:
          Tallahassee Florida
          Local Time:
          7:21 AM
          I've never had a slant six nearly as fast as Charrlie_S's, but my 67 Barracuda used to have a slant six. Stock except for a four barrel carb, Offy intake, stock exhaust manifold with 2.25 inch pipe, automatic and 3.23 gears, it ran low 18's in the quarter. Milled the head a hundred thousandths and swapped in a 264/.440 Comp Cam (220 @ .050) - that dropped a full second off the quarter mile ET. Could have used more torque converter as my 60 foot time was only 2.50 (same as with the stock cam and CR), but I never bothered changing it or gears or anything else (until I swapped in a 360). Compared to the stock cam, the Comp Cam really woke it up from about 25 mph on up. It made for a nice daily driver, in town or on the interstate (could easily cruise at 80-85), with good passing power and a decent top end (110-115).
           
        • hellfirechrome

          hellfirechrome Well-Known Member

          Messages:
          341
          Likes Received:
          24
          Joined:
          Aug 7, 2009
          Location:
          Tahoe
          Local Time:
          4:21 AM
          Yeah I'm new to living at elevation, looks like either a blower or shaving the heads is the only way I'm gonna get her to wake up. Looking forward to my trip to Sacramento in a few days, 50ft above sea level and SO many nice cruising spots... but I know I'll be able to feel the difference at sea level. Even my jeep V8 5.2 just wheezes up here LOL
           
        • Andyz

          Andyz Well-Known Member

          Messages:
          74
          Likes Received:
          12
          Joined:
          Mar 12, 2014
          Location:
          Felton Ca.
          Local Time:
          4:21 AM
          Have you considered one of the throttle body EFI units available now? I just put one on my slant (Holley Sniper 4 bbl) and it made a huge difference. I had the Eddy 500 and a Holley 390 which were good but the closed loop control of the EFI just makes everything a lot easier, especially if you want to drive down the hill without changing out your fuel rods. There are 2bbl version as well from a few of the makers of these EFI units (Fitec, Edelbrock, MSD, etc.). The biggest improvement I noticed is Idle smoothness and part throttle power. Just a game changer for my car. They ain’t cheap, but probably the best bang for the buck.
          I have an old MPP purple slant cam, similar to the Comp Cams that 65 Cuda 340 has and it really needs higher compression to work at lower rpms. You could shave off .080” and still run regular gas with that cam. Erson Cams has some really nice grinds too for the slant thou I don’t know if they still make them.
          Best of luck on your project and keep us posted!
           
          Last edited: Sep 7, 2020
        • hellfirechrome

          hellfirechrome Well-Known Member

          Messages:
          341
          Likes Received:
          24
          Joined:
          Aug 7, 2009
          Location:
          Tahoe
          Local Time:
          4:21 AM
          Well, gentlemen, I've come to a good point! Since installing the Edelbrock and intake, finally finding a good tune (.83 jets, 6552-ish needles, I'd have to double check, and 8hg silver springs with the accelerator pump on the top hole), she was running pretty good but stumbly. Finally went back to address the timing, since I hadn't done her timing yet since the 4bbl install. Gave the dizzy a gentle twist to the left, and VIOLA! She picked up a smoother idle, I knew I hit the jackpot (I shoulda looked here first!). We took her for a spin and BAM! Power returned.

          Just got back from a drive over hwy 88, Kit Carson pass at about 9,000ft elevation... she ran like a gem! Slightly rich up there, but plenty of power and hillclimbing in 2nd.

          I think I'm pretty happy with the power output for now, but I'll look into thin head gaskets or a head shave soon. Still, that old saying applied in changed her road habits entirely; "timing is everything!"
           
        • BillGrissom

          BillGrissom Well-Known Member

          Messages:
          7,394
          Likes Received:
          411
          Joined:
          May 10, 2009
          Location:
          Sacramento
          Local Time:
          4:21 AM
          Have you looked at the new Chinese electric superchargers? I've seen some youtubes. The cheap ones are worthless and even restrict airflow, but the $500+ ones actually work. I think that is the future, and certainly simpler and more elegant than the plumbing chore of a turbocharger or mounting a giant and expensive belt-driven supercharger. I understand there are current production cars with one (M-B). As one guy here promoted (Bill Dedman I recall), the slant six is a perfect candidate for boost. The small valves with manifolds on one side don't matter if you force the air in. Ditto for a high-lift camshaft.
           
        • RustyRatRod

          RustyRatRod Bla de blizhibliz de blatde blizi bla bla FABO Gold Member

          Messages:
          65,845
          Likes Received:
          39150
          Joined:
          Jun 7, 2010
          Location:
          Georgia
          Local Time:
          7:21 AM
          Did you actually put a light on it? It's important you actually know where the initial and total timing is.
           
        • Slantsix64

          Slantsix64 Well-Known Member

          Messages:
          2,794
          Likes Received:
          1107
          Joined:
          May 11, 2014
          Location:
          SGV
          Local Time:
          6:21 AM
          Thats crazy my 500cfm eddy was lean out the box, actually had to jet up to .89 with with stock
          rods secondaries where 1 stage leaner, i have the avs version. but my motors no stock probably how did you tune your carb with an Air fuel ratio sensor?
           
        • hellfirechrome

          hellfirechrome Well-Known Member

          Messages:
          341
          Likes Received:
          24
          Joined:
          Aug 7, 2009
          Location:
          Tahoe
          Local Time:
          4:21 AM
          Yeah for a stock motor there's no way she was going to use all of that gas, I went through multiple jets and needles to get it idling smooth and using all the fuel under acceleration, not to mention timing. It was all centered around that damn bog. Now that I have the timing where it needs to be, I'm gonna play with needles and accelerator pump again to dial it in. I'm old school, I tune by driving and exhaust rich/lean smell. Learned from the best as a teen working on dad's Studebakers. I'll get an AFR soon, but she's driving so well (even at altitude!) that I don't care about an extra 10hp here or there. Just happy with smooth power (feels like a 273!) and cold running. I run a 160 thermostat, step up to a 180 in winter. Will also put an electric heat pad under the hyper-pak intake/carb plenum for the winter.
           
        1. This site uses cookies to help personalize content, tailor your experience and to keep you logged in if you register.
          By continuing to use this site, you are consenting to our use of cookies.