318 head porting for the average joe

Small Block Mopar Engine

  1. Hysteric

    Hysteric Well-Known Member

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    NO its a street/strip deal.
     
  2. MOPAROFFICIAL

    MOPAROFFICIAL FABO Gold Member FABO Gold Member

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    How you make it repeatable. Actually for 273 only, you can unshroud more for a 318 bore.
    You use spark plugs in the head bolt holes.

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    Last edited: Feb 24, 2020
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    • Hysteric

      Hysteric Well-Known Member

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      Car went 13.04 @ 102.5 mph shifting @ 5750 with the secondaries barely opening on a Eddie 600 carb. Not bad for 318 heads.........:rofl:
       
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      • Bronze Barracuda

        Bronze Barracuda Well-Known Member

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        OK this is what I've got. ;)
        I need a little advice from whomever,
        1968 Barracuda has original 318 block with 273 (315) heads on it. Strangely they have rocker shafts and an eddy torker intake bolted to it?
        I also have a 360 53006921
        and more heads 714 castings
        and 360 heads 3418915-H
        I'd like to build a streetable easy (cheap) 350-375 HP motor.
        Before I started reading this thread I thought the way to go was the 360 with the 915 heads but now I am not so sure.
        I do not mind doing porting (learning)
        So with that in mind and what Ive got which way should I go?
        A few things that I have to consider transmission is a 904 and I will be keeping it that way with a 742 8.75 rear with 323's I am thinking also about balancing as well the original 904 torque converter may need to be rebalanced if I go with the 360??
        Any thoughts/advice greatly appreciated. Thanks all.
         
      • Jadaharabi

        Jadaharabi FABO Gold Member FABO Gold Member

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        Use the 915 heads. Do a little porting & a little milling then a touch of camming and bingo you have met you goal.
        Moparoffical has my 915s flowing 260 cfm at .500 lift.
        Btw all LA motors have rocker arm shafts. It's usually what is mounted to them that may be differant.
        Freshen up the 904 and put a correctly wound front clutch pack spring in it.
        Use a b&m 360,904 flexplate and run a neutral balanced torque converter behind it.

        Now that we've derailed this thread real good. Go back to talking about the heads.
         
        Last edited: Apr 22, 2020
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        • Jadaharabi

          Jadaharabi FABO Gold Member FABO Gold Member

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          My head question for today.

          Is it beneficial to smooth or polish up the combustion chamber?
          I have seen some that the chamber is so polished they almost look like Chrome.

          Or would it be more beneficial to use some of those new coatings on the combustion chamber?
           
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          • Bronze Barracuda

            Bronze Barracuda Well-Known Member

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            Yes thanks. Main body of the question definitely on the porting possibilities between the three heads and which would be the least amount in cost and labor. Sorry about the diversion, just had a some concerns that might steer the opinion on which heads to use. But quite impressed with the 318 head flow with some porting. I had never gave them a thought as a performance possibility.
             
          • oldkimmer

            oldkimmer FABO Gold Member FABO Gold Member

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            I have a set of heads that have been ceramic coated in the CNC ports and the combustion chambers. Also he laid down a head gasket and did the surface around the chambers. Kim

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            • MOPAROFFICIAL

              MOPAROFFICIAL FABO Gold Member FABO Gold Member

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              For those who have contacted me about the 920 heads... they are already sold to a member of this site. I will do more of these as the cores become available.
              Thanks.
               
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              • MOPAROFFICIAL

                MOPAROFFICIAL FABO Gold Member FABO Gold Member

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                Dont port 273/318 heads for a 360, use and port the 915 heads, 1.94/1.60 chevy valves work great for the lesser work approach to 250cfm.
                If you've never ported anything, dont have a grandeurous expectation.
                 
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                • MOPAROFFICIAL

                  MOPAROFFICIAL FABO Gold Member FABO Gold Member

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                • oldkimmer

                  oldkimmer FABO Gold Member FABO Gold Member

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                  Yes big block heads. Kim
                   
                • Jadaharabi

                  Jadaharabi FABO Gold Member FABO Gold Member

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                  Aren't the chevy valves 11/32 stem instead of 3/8?
                   
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                  • oldkimmer

                    oldkimmer FABO Gold Member FABO Gold Member

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                    Alum heads have 11/32 valves
                     
                  • MOPAROFFICIAL

                    MOPAROFFICIAL FABO Gold Member FABO Gold Member

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                    Yep, and you cant cut seats on worn guides..unless you want non concentric seats...so guides get changed anyways.
                     
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                    • Bronze Barracuda

                      Bronze Barracuda Well-Known Member

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                      I've got a set of cracked magnum heads (Obviously)
                      I'll practice porting on them
                       
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                      • Wyrmrider

                        Wyrmrider Well-Known Member

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                        Last edited: Apr 28, 2020
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                        • MOPAROFFICIAL

                          MOPAROFFICIAL FABO Gold Member FABO Gold Member

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                          • Ottmundr

                            Ottmundr 68 Fastback

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                            How much does the ceramic coating help in keeping the heat in the combustion chamber and in the exhaust and does the engine run noticeably cooler?
                             
                          • oldkimmer

                            oldkimmer FABO Gold Member FABO Gold Member

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                            I don’t have any info on ceramic coating. These were coated b4 I got them. I have also see piston tops ceramic coated. Kim
                             
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                            • glhx

                              glhx Well-Known Member

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                              Does a 318 porting template exist. There are enough working on these engines now to warrant something like that
                               
                            • rumblefish360

                              rumblefish360 Getting closer FABO Gold Member

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                              No
                               
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                              • glhx

                                glhx Well-Known Member

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                                That’s unfortunate
                                 
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                                • MOPAROFFICIAL

                                  MOPAROFFICIAL FABO Gold Member FABO Gold Member

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                                  You would have to make them by casting since the as cast short turns varied quite a bit. 273's castings were laid back a lot more than say a 675 or 163.
                                   
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                                  • volaredon

                                    volaredon Well-Known Member

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                                    I have a 318 head question.... I have heard the answer go both ways just in reading others' posts. I have a 78 B body Fury, with its original 318. I think it has the "163" heads, it's whatever it left the factory with. car has 55K original miles. never been apart, beyond resealing timing cover and intake. only deviation from stock so far, is true duals all the way to the bumper. still has 2 bbl and Lean Burn even. I have had this car since 2007. I'm 2nd owner, it had 38K on it when I got it.
                                    I have a fresh from the machine shop set of '302 heads on the shelf. Surfaced just enough to assure a good gasket seal. something like 0.005-0.007. Are they or aren't they worth a $#!t? I've heard they are the best heads (they have the heart shaped closed chamber) and here lately, I have heard people say that they really aren't worth a S#!t. Stock (unported so far) vs the '163 heads are they worth a S#!t? are they worth any seat of the pants HP improvement, with all else on my engine being equal? Are they worth the effort to spend a Saturday afternoon swapping out?
                                    I had one 318 that I did the Magnum head conversion on and really woke that one up when combined with the same cam and 4 bbl that I want to put onto this one.
                                    I don't have any good Magnum heads on hand at the moment. These 302s are what's on my shelf.
                                    I had somebody give me pretty good money via CL for the last set of std '163 heads I had. same thing would happen to the ones currently on this engine.
                                    I do plan to lose the Lean burn, add a small cam, swap to a 4 bbl intake and carb (I have a couple of those here to pick from///an Offy and a Performer) regardless.
                                    this will never be a race car, I never wanted it to be. but I want to wake it up a bit. These are what I have on hand, certainly not spending the coin on aluminum heads for this one. just a cruiser, and sometime back n forth to work vehicle in nice weather. My wife might take that one over for this year, if I get my D150 done to the point I want to get it to this spring. so it cant go too radical. AC still full of R12 and working. Want it to stay like that.
                                    I may open them up (the 302s) and try to do a little porting on them (casting flaws mostly) if I can do so without screwing up the fresh valve job (they do have 16 new valves in them)
                                     
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