Manifolds or headers?

Mopar Exhaust Systems

  1. Glenwood

    Glenwood FBBO Gold Member FBBO Gold Member

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    I know you guys are far more knowledgeable about this stuff than I, but what do you think about articles like this one from HR?

    http://www.hotrod.com/articles/mopp-0106-manifolds-vs-headers/
     
    Last edited: Feb 10, 2018
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    • Dennis H

      Dennis H FBBO Gold Member FBBO Gold Member

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      • oldbee

        oldbee FBBO Gold Member FBBO Gold Member

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        You said "low speed torque" in OP, cast iron manifolds IMO. Way easier for piping,etc.; and you'll never notice the difference. Headers are nice, but a waste IMHO for what you want. Cast iron will last forever/almost.
         
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        • dadsbee

          dadsbee FBBO Gold Member FBBO Gold Member

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          My 49 year old manifolds.

          beerestoration2017 754.JPG beerestoration2017 751.JPG
           
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          • moparnation74

            moparnation74 Well-Known Member

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            Relating to the OP's build I wouldn't even consider headers.....The stock manifolds are perfect for his application. You can get the cast iron manifolds ceramic coating internally improving flow and to reduce heat.....

            It is whatever makes you happy but based on his application you would be wasting money....And all you can say is they weigh less and reduce a little more heat....

            As far as performance goes and based on this build there would be no noticeable difference IMHO

            The 2001 article is way out of date and there are more current ones showing realistic comparisons
             
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            • Ranger16

              Ranger16 Well-Known Member

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              I once asked a GM powertrain engineer about that and he said probably 15-20 HP would be the minimum seat-of-the-pants feel.
               
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              • wyrmrider

                wyrmrider Well-Known Member

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                Did you mention your compression and gears?
                fill this out and post the results
                Mike's MOPAR special might be just what you are looking for
                I have one in my 440 with HP manifolds, dual cop car exhausts, TQ, true 9:1, ported 915 heads .030 quench TF trans
                http://jonescams.com/street-performance/
                 
              • Kern Dog

                Kern Dog FBBO Gold Member FBBO Gold Member

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                All the guys that complain about headers are either repeating what they heard without having any direct experience or they have not had experience with good quality headers like TTI or Dougs.
                Modern headers fit well, don't burn plug wires and the gaskets last. My TTIs I bought in 2006 only need gaskets when I have removed them, they have never burned out on their own. They clear everything. Plug wires are clear. Plug access is not bad.
                Starter access? Yeah...it is better with manifolds but how often do you change starters? Buy a good one, not a 200,000 mile junkyard starter and it isn't an issue.
                The people that think the cast iron manifolds flow just as well as headers do not understand how headers work. A 400 HP engine will make 25 or more HP with headers, run cooler and weigh less.
                A stock 440 will run fine with manifolds but it would make more power with headers. With good headers, there are very few minor drawbacks.
                 
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                • lewtot184

                  lewtot184 Well-Known Member

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                  cast manifolds will run well over 700F, tubing about 450F. cast iron holds heat, tubing doesn't. ceramic coating cast manifolds will only keep them nicer looking; does absolutely nothing for heat.
                   
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                  • wyrmrider

                    wyrmrider Well-Known Member

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                    all true but cast manifolds are quieter
                    want to cut down heat
                    those late 70's cherry red stock exhausts can be cut 700 degrees
                    run a shorter cam with lots of lift
                    cut down overlap
                    run tight quench
                    you can cut header temp same way
                     
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                    • Sonny Black

                      Sonny Black FBBO Gold Member FBBO Gold Member

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                      TUBE TECHNOLOGIES, INC..........and then move on to the next question...

                      A suggestion from Sonny:popcorn::popcorn2::drinks::luvplace:
                       
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                      • rumblefish360

                        rumblefish360 Well-Known Member

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                        Excellent torque is VERY doable with exhaust manifolds. Moving up in duration will not only move the HP level up but also the torque. Keep the cam small.
                        The better the engine moves air in and out, the more efficient the engine will make power.

                        Headers are not a must. But help.

                        Cam recommendations are best made when you describe what your doing with the car, what you expect it to do and perform as well as, as many engine specs that you can surply and finally what trans, stall, rear gears and tire size.
                         
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                        • lewtot184

                          lewtot184 Well-Known Member

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                          quieter? yes. the other stuff makes no difference for heat. been there, done that.
                           
                        • WileERobby

                          WileERobby Well-Known Member

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                          Here we go again with this manifolds vs. Headers debate. It's like blonds vs. Brunettes, & what are you gonna use them for ????
                           
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                          • Dennis H

                            Dennis H FBBO Gold Member FBBO Gold Member

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                            Blondes!
                             
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                            • FrnkNsteen

                              FrnkNsteen Well-Known Member

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                              For the record, I am not asking if manifolds or headers are better. Everyone should know the advantages of headers, and the power they can add (if the mating components can benefit from improved flow). My question was if HP manifolds would be sufficient if I am just building a cruiser and just want a little extra torque over stock. I am using stock 906 heads, which everyone says don't have a lot of flow, so do I really need headers to build a nice cruiser motor.

                              We all have a budget, and body work is eating up a substantial part of that budget. I have 2 sets of 906 heads, 1 set of 915 heads (currently held for a possible 400 rebuild in the cuda), and 2 sets of HP manifolds. If I could save some money by using the components I have and still build a decent torque motor for the street, that would be helpful.

                              Hence my questions of:

                              "Can I get away with using the HP manifolds and still get good low end torque performance for the street?" (Yes/No) and "Can someone recommend a good cam to go with this type of setup."

                              Car has AC, and vacuum accessories for headlights and heater/ac controls, so I want a good torquey motor with good vacuum. I looked at some of the cams suggested by some, and it looks like duration on those is running from 208 - 224 on intake and 213-241 on exhaust. Lifts of those three cams suggested are .486/.473, ,454/,454, and ,466/,488

                              Sounds like if I want to build low-end torque, I would want a decent lift, with less duration and overlap. Am I understanding that correctly?

                              Specs I know of at the moment:
                              Forged pistons, shooting for 9.25 SCR
                              Stock 906 heads
                              Likely stock intake, possible Edelbrock RPM intake (to avoid need for adapter to fit aftermarket carb)
                              Stock '69 HP exhaust manifolds through 2 1/2 dual pipes out the back. Likely Super Turbo or Magnaflow mufflers (quiet but rumbly)
                              A833 4 spd
                              8 3/4 Sure-grip with 3:23 gears
                              Car has AC, power steering, and manual brakes
                              Likely 255/60R15 rear tires. Maybe 275/60R15
                               
                              Last edited: Feb 13, 2018
                            • FrnkNsteen

                              FrnkNsteen Well-Known Member

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                              By the way,... Thanks to everyone for their suggestions. I just don't want to build a turd. I'm hoping to find the right combination of parts to make this run good without going overboard. How many times have we heard of someone going with WAY too much cam for the intake, heads, and exhaust they have. I just want a good balance of parts that will work well together.

                              Thanks again!
                               
                            • 451Mopar

                              451Mopar Well-Known Member

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                              Here is what I am thinking on the build.
                              Guessing your using stock 3.75" stroke crank, and stock rods with ARP rod bolts, and maybe 0.030" overbore?
                              I would look to use a piston like the SRP 213455-8. It lets you use the 1/16" piston rings, is 2.062" compression height Forged Flat top piston with 6.0cc valve reliefs, and has the stock size 1.094" pin diameter. If your 906 heads are 89cc and you use a 0.040" head gasket, compression should be about 9.31:1, with a 0.020" head gasket 9.71:1 (assuming a block height of 10.725", where the piston would be about 0.020" below the deck at TDC.) This would work for you, and allow future upgrades if you want to.
                              https://www.summitracing.com/parts/srp-213455-8/overview/

                              For a cam, I would use the Hughes Engines SEH1620BL. It is 216/220 @ 0.050" duration, 0.495"/0.503" lift, 112 LSA, installed at 108 ICL.

                              I would just use a regular performer intake manifold. It is shorter than the RPM making hood clearance easier.
                              With the aluminum intake, use the Valley pan/gasket that blocks off the heat crossover. Fel-pro #1215
                              https://www.summitracing.com/parts/fel-1215/overview/

                              For the exhaust, the manifolds will be OK and not kill the budget, but I would get the 2.5" TTI dual exhaust system with their manifold adaptors. I'd go "H" pipe crossover for this for a meaner sound. The mandrel bent exhaust system will flow way better than some cheap system with crumpled up bends. The TTI system normally comes with Dynomax Super Turbo mufflers which sound OK. I think you can get the kit without mufflers too if you want to use a different type or brand of muffler.
                              If you decide to go headers in the future, the TTI headers should easily connect up to their exhaust system.
                               
                            • rumblefish360

                              rumblefish360 Well-Known Member

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                              Sorry I wasn’t clear, so I’ll be dead blunt.

                              YES!

                              The exhaust manifolds will do fine.
                               
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                              • FrnkNsteen

                                FrnkNsteen Well-Known Member

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                                Thanks 451! You hit it right on the head. Stock stroke, stock rods with new bolts. The pistons and the .040" head gasket compression you mentioned matches up well with the CR range he suggested. The cam you recommended matches up real close in duration to the Lunati Voodoo that Yatzee recommended, with a little more lift, and close to the Comp and Summit cams others recommended. I was looking at the Performer intake for that same reason (lower height), plus if I remember correctly it had a lower power band than the Performer RPM intake. I don't know that the intake will offer much improvement with stock

                                I will look into the TTI exhaust system. I looked at their headers after so many recommended them, but haven't looked into the rest of their exhaust system.

                                You were clear Rumblefish, and I appreciate it. Your suggestions lined up with others that gave specific suggestions. I was referring to others that gave the "Here we go again" type response and asking what I am going to use it for, when the original post clearly said I was looking for a nice torquey street cruiser and not a race motor.

                                Thanks to everyone for their responses. It was nice to have some reassurance that I won't be building a dog if I stick with the parts I have. I also appreciate the cam suggestions. I understand how the pieces work, but don't have enough working knowledge to piece part a good package together. Your suggestions will give me some background information for when I sit down with the engine guy, so I can either have confidence when he agrees with you guys, or question it if he doesn't.

                                Thanks again!
                                 
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