captinjohn

Thanks for the bump up....it is very good data. I forgot about the "Booster Gap" search so here is a link to that. http://www.summitracing.com/search/p...pe/spark-plugs

captinjohn

Booster gap sparkplug.

<nobr>TRUCK SERVICE MANUAL</nobr> <nobr>TM 5-4210-230-14&P-1</nobr> <nobr>ELECTRICAL</nobr> <nobr>INSTALLATION</nobr> <nobr>When installing spark plugs, always be sure gasket seats and</nobr> <nobr>threads are clean.</nobr> <nobr>Using a torque wrench, tighten plugs to 2830 ft. lbs.</nobr> <nobr>BOOSTER GAP PLUG</nobr> <nobr>For the past several years auxiliary gap (Booster Gap)</nobr> <nobr>spark plugs have been used in certain IH engines,</nobr> <nobr>Fig. 19</nobr> <nobr>Prior to IH approval, the Booster Gap design was</nobr> <nobr>thoroughly tested and evaluated, at which time their anti-</nobr> <nobr>fouling characteristics were firmly established.</nobr> <nobr>What is a Booster Gap plug?</nobr> <nobr>This plug has an internal air gap between the center electrode</nobr> <nobr>and the terminal stud.</nobr> <nobr>How do they work?</nobr> <nobr>Most servicemen know that misfire will occur when a</nobr> <nobr>conventional spark plug is fouled. As the coil attempts to build</nobr> <nobr>up voltage on the "dirty" firing end, it "sees" an easier path to</nobr> <nobr>ground over the deposits. This short circuit prevents normal</nobr> <nobr>voltage buildup. The Booster Gap, however, isolates the coil</nobr> <nobr>from the fouling deposits, allowing near normal voltage build-</nobr> <nobr>up. The instant the Booster Gap sparks, sufficient voltage</nobr> <nobr>appears across the firing gap and normal ignition results.</nobr> <nobr>When you remove a plug wire from a fouled plug and let the</nobr> <nobr>spark jump from the cable to the plug terminal to make the</nobr> <nobr>plug fire, you are using this same Booster Gap principle.</nobr> <nobr>Where are Booster Gap plugs used?</nobr> <nobr>Maximum benefit from this design is obtained in</nobr> <nobr>engines that operate over a wide load and speed range. For</nobr> <nobr>example, a heat range cool enough for highway service will</nobr> <nobr>have better fouling protection during stop-start city delivery</nobr> <nobr>service with the Booster Gap.</nobr> <nobr>Furthermore, the Booster Gap has been instrumental in</nobr> <nobr>reducing the complaints of "break-in fouling" in new engines.</nobr> <nobr>In many cases misfire due to oil fouling in older</nobr> <nobr>engines can be relieved simply by using the recommended</nobr> <nobr>heat range plug incorporating a Booster Gap.</nobr> <nobr>A cure-all?</nobr> <nobr>Not </nobr><nobr>at </nobr><nobr>all. </nobr><nobr></nobr><nobr>Booster </nobr><nobr>Gap </nobr><nobr>plugs </nobr><nobr>used </nobr><nobr>where</nobr> <nobr>recommended and applicable to help solve fouling problems</nobr> <nobr>will give excellent results. However, the need for the correct</nobr> <nobr>selection of plugs in the proper heat range based on type of</nobr> <nobr>vehicle operation is important.</nobr> <nobr>Where more severe conditions of fouling as a result of</nobr> <nobr>light service application or break-in fouling on engines occurs,</nobr> <nobr>the alternate recommended hotter type plug with Booster Gap</nobr> <nobr>should be used.</nobr> <nobr>Voltage Requirements</nobr> <nobr>While nominal in amount, the Booster Gap does</nobr> <nobr>require more voltage initially than conventional spark plugs.</nobr> <nobr>This higher requirement diminishes, however, after several</nobr> <nobr>thousand miles of use.</nobr> <nobr>Most any ignition system has more than adequate</nobr> <nobr>reserve to supply the bit of extra voltage requirement; if you</nobr> <nobr>experience misfiring with Booster Gap plugs and not with</nobr> <nobr>conventional plugs, chances are the ignition system is</nobr> <nobr>marginal.</nobr> <nobr>It should also be pointed out that Booster Gap plugs</nobr> <nobr>are not resistor plugs. If radio interference is a problem on</nobr> <nobr>older vehicles having nonresistor ignition cables, it may be</nobr> <nobr>necessary to install resistance leads (cables). Booster Gap</nobr> <nobr>plugs may be used in conjunction with resistance-type ignition</nobr> <nobr>cables to obtain interference suppression and still obtain the</nobr> <nobr>added benefits of the Booster Gap. This is the combination</nobr> <nobr>that is recommended on all gasoline powered motor truck</nobr> <nobr>engines.</nobr> <nobr>CTS-2016-J Page 8</nobr> <nobr>PRINTED IN UNITED STATES OF AMERICA</nobr>

ahicks

My Feedback: (2)

Yes, make sure those plugs are torqued to 2830 ft. lbs.!

dirtybird

My Feedback: (5)

Well I disagree.
The ringing on the old point type was an important source that made the spark stronger. The capacitor in series with the coil formed a series resonate frequency unit. Each time the charged bounced back and forth between the capacitor and the coil an additional spark was generated. Thus several hundred sparks were generated and produced a fat spark.
If you doubt this try an old spark system and remove the capacitor. You will still get a spark but your engine will not run properly. The capacitor also helped prevent arcing in the points but that was the result of having the capacitor to dump the charge into instead of across the points.
I think the resistor limits the risetime of the square wave produced when the spark shorts out the pulse from the coil.
If you analyze a square wave you will come to the conclusion that the rise time creates the highest frequency produced by the wave. You limit the rise time and you limit the frequencies below that that will interfere with your system.

JeffH

My Feedback: (43)

I saw that too....My 30" torque wrench onlyh goes to 360 ft-lbs....I guess if I put a 10 foot pipe on it and stand on the other side of the driveway, I can get 2830 ft lbs!! lol

captinjohn

Idea.....place a big fan blade on that 10 foot pipe and use some of the your "Hot Air" and get even more ft pounds...maybe break the pipe!

WRK

My Feedback: (2)

In CD systems the duration of the spark is determined in large part by the leakage inductance in the ignition coil as well
as the energy stored in the capacitor, generally speaking there is little
series resonance effect between the coil primary and the capacitor
because any ringing current trying to go through the SCR backwards turns off the SCR immediately, divorcing the
capacitor from the coil (actually the coil is more properly called a pulse transformer, it is not the primary storer of energy).
There is some oscillation formed by the stray capacitance of the secondary (high voltage) winding of the pulse transformer
and it's inductance, the RF noise generation is the result of the very fast rise time of the secondary voltage of a CD system,
this rise time is on the order of + or - one microsecond and the duration of the spark on small systems like we use on our engines is
on the order of 100 micro seconds. The suppression resistors job is to reduce the rise time and damp the secondary circuit in conjunction
with the secondary stray capacitance. The suppression resistor does reduce the energy available at the spark plug which limits
how much resistance can be used.