Announcement

Collapse
No announcement yet.

spark plugs

Collapse
This is a sticky topic.
X
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • #46
    Champions tech notes on Heat Range

    This is a good read for newbies and veterans alike. From Champion spark plugs

    Heat range

    The term spark plug heat range refers to the speed with which the plug can transfer heat from the combustion chamber to the engine head. Whether the plug is to be installed in a boat, lawnmower or racecar, it has been found the optimum combustion chamber temperature for gasoline engines is between 500°C–850°C. When it is within that range it is cool enough to avoid pre-ignition and plug tip overheating (which can cause engine damage), while still hot enough to burn off combustion deposits which cause fouling.

    The spark plug can help maintain the optimum combustion chamber temperature. The primary method used to do this is by altering the internal length of the core nose, in addition, the alloy compositions in the electrodes can be changed. This means you may not be able to visually tell a difference between heat ranges. When a spark plug is referred to as a “cold plug”, it is one that transfers heat rapidly from the firing tip into the engine head, which keeps the firing tip cooler. A “hot plug” has a much slower rate of heat transfer, which keeps the firing tip hotter.

    An unaltered engine will run within the optimum operating range straight from the manufacturer, but if you make modifications such as a turbo, supercharger, increase compression, timing changes, use of alternate racing fuels, or sustained use of nitrous oxide, these can alter the plug tip temperature and may necessitate a colder plug. A rule of thumb is, one heat range colder per modification or one heat range colder for every 75–100hp you increase. In identical spark plug types, the difference from one full heat range to the next is the ability to remove 70°C to 100°C from the combustion chamber.

    The heat range numbers used by spark plug manufacturers are not universal, by that we mean, a 10 heat range in Champion is not the same as a 10 heat range in NGK nor the same in Autolite. Some manufacturers numbering systems are opposite the other, for domestic manufacturers (Champion, Autolite, Splitfire), the higher the number, the hotter the plug. For Japanese manufacturers (NGK, Denso), the higher the number, the colder the plug.

    Do not make spark plug changes at the same time as another engine modification such as injection, carburetion or timing changes as in the event of poor results, it can lead to misleading and inaccurate conclusions (an exception would be when the alternate plugs came as part of a single precalibrated upgrade kit). When making spark plug heat range changes, it is better to err on the side of too cold a plug. The worst thing that can happen from too cold a plug is a fouled spark plug, too hot a spark plug can cause severe engine damage

    Comment


    • #47
      a
      Last edited by AndrewT(Do not do business with me).; 01-14-2004, 09:26 PM.

      Comment


      • #48
        Well I canceled my order for A55V plugs! I want a surface gap plug for my car, what's out there?

        What about the A59V plug? It's a warmer then the 55, where can that be found?

        Anything? What up with the XR2CS?
        I feel that I have the HP and mods to go a couple of steps colder on a plug.

        Do not click
        At least it's German

        Comment


        • #49
          To add to this tread and based on the info from AT and Champion: I trashed my rod bearings back in May. I had no warnings - car ran great and had only 81K miles on it (only engine mod was a JC chip). I was at the track when *I think* the damage occured. I was running a 91/100 octane mix (net octane was probably around 94). I'm now in the process of rebuilding. (OUCH!) Since then, I've been trying to figure out what caused my engine damage so it won't happen to my new engine (or YOURS). The usual suspects are on the list: AFM, baro sensor, ECU, fuel pumps, injectors, harness shorts, etc. Now add plugs: I was running the NGK D7EA that day. These plugs are the NGK replacements for the stock Bosch plugs. When I took the D7EA's out, the electrodes were white on the bottom. This indicates a lean (or hot) condition. I'm now wondering if the damage was done by the plugs and their inability to reduce the heat in the cylinders and thus causing pre-ignition and in turn my rod bearing damage. According to the Champion info, this is a plausible scenario.

          I hope this post isn't considered self-serving; its just that I wouldn't wish a blown S14 'on my worst enemy'. To that end, I would not use a D7EA plug on the track (or perhaps even the stock Bosch's). Street driving (i.e. no extended high-rpm periods) would probably be OK with these plugs, or engines that are older and burning some amount of oil. Perhaps all track events should be done with the Bosch XR4CS or maybe the NGK D8EA's. At the moment, I think I'll stay away from the NGK's all together. I know many folks are using the XR4CS's in their daily drivers w/o any problems... as the Champion info suggests, its safer to run a colder plug than a hotter one... HTH

          -Dietrich

          Comment


          • #50
            Dietrich, colder wont hurt you.

            On a stock engine, the stock X5DTC plug is more than
            adequate regardless of what track you run or how long
            you run at high rpm.

            Surely you dont believe that euro M3 have not been run
            for hours on end at sustained 6000-7200 rpm?

            Many years ago I used to make a 400 km trip (each way)
            about twice a month. I would wait until the evening
            hours around 21:00 for the traffic to thin out.
            Then Id get in the M3 and drive it pedal to floor
            the entire way, only braking for the someone holding me
            up in left lane or stoping to get gas.

            On one easter sunday some years ago, I drove from Naples
            Italy over to the Adriatic coast, and then took the Autostrada
            up to Rimini. It was almost empty. I drove the car top
            speed the entire time, I got gas about ever 45-50 minutes.

            I put well over 10000 km on a stock S14 at the Nuerburgring,
            just lapping.

            Driven numerous tanks of gas out at nonstop top speed, 7000+ rpm.
            Im sure many european owners have done similar. Nowadays,
            Autobahns are jam packed, you have to look for ones that are free
            to get long times at top speed. Back in the early 90s, you could
            do top speed almost everywhere and for long durations.
            If you lived here, youd have done the same.

            The engine never grenaded and it used X5DTC plugs.

            John

            Comment


            • #51
              Originally posted by John
              On one easter sunday some years ago, I drove from Naples
              Italy over to the Adriatic coast, and then took the Autostrada
              up to Rimini. It was almost empty. I drove the car top
              speed the entire time, I got gas about ever 45-50 minutes.
              Ah, Rimini. I haven't been there since 1990. Tents setup on the beach with "bars" inside. Scantily clad Swedish girls trying to lure you into one night club or another (speaking English in Italy!).

              I, too, drove there with my foot on the floor, but it was in a Fiat Uno Fire 1000 (aka "Formula Uno") company car (the Fire line was completely assembled by robots -- no human hands. The clearances were *huge*....).

              Ah, Rimini....
              Jefrem Iwaniw

              Comment


              • #52
                Originally posted by John
                Dietrich, colder wont hurt you.

                On a stock engine, the stock X5DTC plug is more than
                adequate regardless of what track you run or how long
                you run at high rpm.
                Those are NOT our stock plugs, we get the X5DC. You get the nice 2 electrode plug, we get a generic plug.

                I have tried to get the X5DTC but no one can get them.

                Do not click
                At least it's German

                Comment


                • #53
                  John - Perhaps I should narrow my opinion to just the NGK D7EA's. Maybe they aren't quite up to the task like the X5DC are??? (Mike's right - these are single electrode.)

                  Jefrem - Jefrem! [slap] Snap out of it Man!!! You're in Texas now!!! ;^)

                  -Dietrich

                  Comment


                  • #54
                    Mike, you meant they are 3 electrode plugs...

                    How many sets do you want? They are easy to get here.

                    Dietrich, sorry to go off on tangent and story tell a little
                    Spark plugs can actually get boring after a while

                    Jefrem, yeah lots of parties and girls down there. Funny
                    when you fly to Creta, its similar: blond swede girls trying to
                    invite you into bars

                    That area is also referred to as the "Teutonic Grill" for
                    obvious reasons.

                    John

                    Comment


                    • #55
                      Originally posted by John
                      Mike, you meant they are 3 electrode plugs...

                      How many sets do you want? They are easy to get here.

                      Dietrich, sorry to go off on tangent and story tell a little
                      Spark plugs can actually get boring after a while

                      Jefrem, yeah lots of parties and girls down there. Funny
                      when you fly to Creta, its similar: blond swede girls trying to
                      invite you into bars

                      That area is also referred to as the "Teutonic Grill" for
                      obvious reasons.

                      John
                      Na, I just got a Denso Iridium racing plug IXU01-24 it's a surface gap plug about the same heat range as the XR2CS. There $35 a piece, but what the hell, they also have the QA55V for $5.45 a piece!!

                      Do not click
                      At least it's German

                      Comment

                      Working...
                      X