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    #1

    engine sound?

    Have been wondering about this,

    what has an effect on the sound of an engine? not accssories or the fan spinning, not what comes out of the exhaust pipes, but the rumbling under hood. Why does one small block V8 sound so much different than another? I have been in cars where the sound from the front ofthe car is louder than what's coming out the back


    My first guess would be intake/exhaust on the motor itself - would headers change the sound compared to manifolds? Bigger exhaust ports on the heads.

    Do carbs sound different than the intakes on an efi motor? Size of carb/intake or cai vs wai


    I am assuming that anything that air passes through has an impact on the sound but I'd like to learn what has the biggest impact. Empty space under there (with no accessories or intake tube or power anything) would let the sound bounce around more too I *think*.....anyway let me know if any of my assumptions are wrong and what is correct
    sigpic


    - 1990 Ford LTD Crown Victoria P72 - the street boat - 5.0 liter EFI - Ported HO intake/TB, 90 TC shroud/overflow, Aero airbox/zip tube, Cobra camshaft, 19lb injectors, dual exhaust w/ Magnaflows, Cat/Smog & AC delete, 3G alternator, MOOG chassis parts & KYB cop shocks, 215/70r/15s on 95-97 Merc rims

    - 2007 Ford Escape XLT - soccer mom lifted station wagon - 3.0 Duratec, auto, rear converter delete w/ Magnaflow dual exhaust

    - 2008 Mercury Grand Marquis Ultimate Edition - Daily driver - 4.6 2 valve Mod motor, 4R75E, 2.73s. Bone stock
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    #2
    well, the exhaust system itself has a huge amount to do with how it sounds, what sort of mufflers, converters or no, H pipe, straight pipes, single exhaust, etc.

    The compression ratio of the engine plays in as well. Higher compression tends to have louder exhaust. The cam profile affects it, the head port design affects it. My car got louder when i put the ported heads on.
    86 Lincoln Town Car (Galactica).
    5.0 HO, CompCams XE258,Scorpion 1.72 roller rockers, 3.55 K code rear, tow package, BHPerformance ported E7 heads, Tmoss Explorer intake, 65mm throttle body, Hedman 1 5/8" headers, 2.5" dual exhaust, ASP underdrive pulley

    91 Lincoln Mark VII LSC grandpa spec white and cranberry

    1984 Lincoln Continental TurboDiesel - rolls coal

    Originally posted by phayzer5
    I drive a Lincoln. I can't be bothered to shift like the peasants and rabble rousers

    Comment

      #3
      My 91's engine is loud. You can head the engine itself over the exhaust alot of the time (and it's fairly loud). Unless your standing right behind the car, all you can hear is the engine.
      2020 F250 - 7.3 4x4 CCSB STX 3.55's - BAKFlip MX4
      2005 Grand Marquis GS - Marauder sway bars, Marauder exhaust, KYB's
      2003 Marauder - Trilogy # 8, JLT, kooks, 2.5" exhaust, 4.10's/31 spline, widened rear's, metco's, addco's, ridetech's 415hp/381tq
      1987 Colony Park - 03+ frame swap, blown Gen II Coyote, 6R80, ridetechs, stainless works, absolute money pit. WIP

      Comment

        #4
        Geared timing instead of a chain is a lot louder.
        1984 CV tudor 351W, 4bbl, 5-speed best time in the 1/8 8.39 at 80 with 1.80 60ft time.
        2006 P71, 1988 Bronco II, 1986 Baby LTD(5.0 & T5 swap in progress), 1976 16' Hobie Cat, 12' AquaFinn
        http://www.cardomain.com/ride/2651997 UPDATED 20100826
        sigpic

        Comment

          #5
          yea, gear drives sound sweet! i know what you mean. i love being right beside a big block in a big boat cause you can just hear the tingy exhaust note lol

          1981 Mercury Marquis Brougham 2-Door 302/ 5-speed -special blend (GMGT)
          1987 Lincoln Mark VII 5-speed (Errand runner)
          1989 Mercury Grand Marquis (Base Runner)
          2007 Lincoln Town Car Signature Limited (Hustlyn)
          2011 Ford Crown Victoria Police Interceptor (Down with O.P.P)

          Comment

            #6
            valvetrain design also will make some noise differences. Solid lifters are noiser than hydraulic because there is slack in the valvetrain to allow for heat expansion. Solid lifters tend to shut up when the engine warms up, and get louder when cold.
            86 Lincoln Town Car (Galactica).
            5.0 HO, CompCams XE258,Scorpion 1.72 roller rockers, 3.55 K code rear, tow package, BHPerformance ported E7 heads, Tmoss Explorer intake, 65mm throttle body, Hedman 1 5/8" headers, 2.5" dual exhaust, ASP underdrive pulley

            91 Lincoln Mark VII LSC grandpa spec white and cranberry

            1984 Lincoln Continental TurboDiesel - rolls coal

            Originally posted by phayzer5
            I drive a Lincoln. I can't be bothered to shift like the peasants and rabble rousers

            Comment

              #7
              Pushrod V8's have always sounded louder and better in my opinion. I'm not a mopar guy but dodge V8's in-particular sound good, even in stock form.
              2002 Mercury Grand Marquis GS 4.6L V8, 1988 Mercury Grand Marquis GS 5.0L V8, 1979 Lincoln Mark V 6.6L V8, 1977 Lincoln Continental 7.5L V8, 1999 Chevrolet Suburban LT 5.7L V8

              Comment

                #8
                Firing order has some effect, overlap (between the exhaust and intake valves being open on a single cylinder) is what will give you the racing idle sound, though that's mostly exhaust.


                The shape of the intake has a lot of influence on this. For instance, when I took off the stock plastic intake tubing you see on 351 and CFI cars that goes from the metal air cleaner to just behind the header panel, the sound changed a lot because:
                1. the ridges and curves in the intake tubing were no longer there to vibrate from the air
                2. the noise from the carburetor had a straighter and shorter distance to get out into the open air and to the ears of people standing by the car
                3. part of the design of the intake tubing was to "silence" the air. On newer cars, it gets even more complex with all sorts of weird boxes and offshoots meant to do things to the sound of the intake through noise-cancelling and resonance based technologies. see below (from an Impreza)

                85 4 door 351 Civi Crown Victoria - Summer daily driver, sleeper in the making, and wildly inappropriate autocross machine
                160KMs 600cfm holley, shorty headers, 2.5" catted exhaust, 255/295 tires, cop shocks, cop swaybars, underdrive pulley, 2.73L gears.
                waiting for install: 3.27's, Poly bushings, boxed rear arms, 2500 stall converter, ported e7's, etc

                06 Mazda 3 hatch 2.3L 5AT (winter beater that cost more than my summer car)

                Comment

                  #9
                  some cars have big stupid silencers on them. The Mark VII has one in the fender. Most newer Panthers have this thing that looks like an inverted funnel in the bottom of the airbox that restricts air and makes it quieter. I remove those for free horsepower and cool sound.
                  86 Lincoln Town Car (Galactica).
                  5.0 HO, CompCams XE258,Scorpion 1.72 roller rockers, 3.55 K code rear, tow package, BHPerformance ported E7 heads, Tmoss Explorer intake, 65mm throttle body, Hedman 1 5/8" headers, 2.5" dual exhaust, ASP underdrive pulley

                  91 Lincoln Mark VII LSC grandpa spec white and cranberry

                  1984 Lincoln Continental TurboDiesel - rolls coal

                  Originally posted by phayzer5
                  I drive a Lincoln. I can't be bothered to shift like the peasants and rabble rousers

                  Comment

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