SPARK PLUG WIRE ROUTING - MOTOR

1 SPARK PLUG WIREIf you look at a road map, it s obvious that there s usu-ally more than one way to drive from point A topoint B. The same applies to ROUTING an engine sspark plug wires. Granted, for a run-of-the-mill pro-duction vehicle, you ll likely always duplicate thefactory-original path. However, for custom engineapplications (street performance, street rods, show cars,etc.), the only rules to follow relate to obtaining solid con-nections and avoiding abrasion and direct contact with high-heat sources, and avoiding wire interference with movingobjects, such as throttle linkage or , it s up for grabs. In addition to function,a customized engine bay can be visually enhanced by cre-ativerouting and mounting of the SPARK plug wires. Herewe ll discuss a few alternative ROUTING approaches, using ex-amples from our engine-building plug wires are allowed to flop around, or are routed sotightly they make constant contact with a sharp object, abra-sion wear may eventually take its toll.

2 Typical high-perfor-mance wires feature fairly thick silicone outer jackets (8mmor more), but constant rubbing over a sharp edge can onlydo harm. Wires are available with braided composite shield-ing that helps protect the outer jacket, which should defi-nitely be considered if you simply can t avoid locationswhere rubbing is a want to avoid extreme heat contact as well, so itshould be obvious to prevent any plug wire from directlycontacting a high-heat source such as an exhaust manifold ortubular header pipes. In cases where you re concernedabout abrasion or heat, protective sleeves and booties areavailable from the performance aftermarket. Design Engi-neering (DEI) offers great stuff for street performance andracing applications. I recently built a 632 , 1115-hpdrag engine where I routed the plug wires directly under thecylinder heads behind the headers.

3 I installed DEI s bootsleeves (a woven Kevlar sleeve that protects the boots andwires). On wires you re trimming to length, install the bootsleeves before attaching the distributor vs. OE RoutingIf the vehicle in question has been restoredto original(where the owner requires every aspect of the build to repli-cate what the factory did when the vehicle was first built),you may have no choice but to use OE-appearing SPARK plugwires (in terms of color, diameter and length), routed exactlyas original, using whatever looms and brackets that , if the vehicle is modified or of a custom nature,the owner will likely not care about original wire design orrouting. Instead, he ll want to create a neat, tidy appearance,with wires that are larger in diameter and of a color thatcompliments the engine and surrounding engine used custom ROUTING usually requires an off-20 October 2011 BYJIMGIBSONROUTI NGIn the underhood area of a performance vehicle, appearancecan benearly as important as function.

4 Creativity can be combined with a widerange of performance ignition products to satisfy both custom en-gine features7mm SPARK plugwires routedthrough 3 8-in. polished attentionto detail duringtube bending resulted in a uniform : Jim Gibsonthe-shelf bracket/loom/separator sys-tem readily available from the perfor-mance aftermarket. Examples includeplastic or aluminum brackets that areinstalled to the outer valve cover fasten-ers, and that run parallel to the valvecovers. wire stand-offs or separatorsmount to the long brackets and serve toorganize the wires. Billet aluminumwire organizers that mount in a similarmanner also are available,but feature a base and topcover that traps the wires, es-sentially hiding them, exceptfor where the wires run fromthe distributor to the orga-nizers, and from the organiz-ers to the SPARK regard to any piecesthat are made from alu-minum, the performance in-dustry always refers to com-ponents as billet, which im-plies that they were CNC-machined from solid billetstock.

5 In reality, many itemsare actually cast aluminumthat are then finish-ma-chined. From a marketingstandpoint, billetis a catchallterm that s popular for any-thing constructed of alu-minum, whether it s true billet or looms/separators are availablefor either horizontal (wires runningalongside each other) or vertical orien-tation (wires stacked), with materialconstruction that includes chromesteel, aluminum and/or a variety ofcomposite a typical V8 or V6 engine thatfeatures a distributor, there are two ba-sic ROUTING paths from which to choose:Run the wires over the valve covers, orrun them along the outboard side ofthe valve covers. In most cases, thechoice will be based on the customer spreference in terms of old school approach is to use tallstand-off brackets that mount to thevalve cover fasteners.

6 Atop these metalstand-off brackets are two-, three- orfour- wire looms that capture the indi-vidual wires. With this approach, thewires run from the distributor to theselooms, then drape over the valve coverson their way to the SPARK plugs . This isthe most common (and least expensive)approach. However, with the currentavailability of a variety of wire organizerstyles, you can get a bit more creativeto achieve a neater and more customappearance while improving wire pro-tection at the same even more creative approach is toview the wire ROUTING as a so-calledclean sheet of paper. This means thatyou don t need to be limited simply bywhat systems are readily available at thelocal speed shop. For example, de-pending on the time/expense factor,you can fabricate custom mounts thatwill accept off-the-shelf wire separatorsand create a ROUTING that s more to theliking of the individual MountingHardwareThe terms used relating to SPARK plugwire mounting may be slightly con-fusing, but we ll try to sort them outfor can refer to anybracket that allows anchoring ormounting wires from a nearby attach-ment point, such as valve cover fasten-22 October 2011 The tubes terminate under the rear dual-quadair cleaner base.

7 The rear air cleaner and fab-ricated aluminum cover tube essen-tially hide the MSD distributor. The aluminumtubes are fitted with 6 hose ends and are se-cured to 1 4-in. NPT/-6 fittings which arethreaded into the base of the rear air RE ON YOUR WAY WITH ANY ACDelco PRODUCT EARNING YOUR earnPOWER POINTS TODAY!Use this QR code for more promotional , intake manifold fasteners, etc. Astand-off features wire separators, al-lowing you to position the loom/separa-tors in a vertical or horizontal term is often misused,and can refer to just about any itemthat secures or groups plug wires. Inaddition, the term loomcan also referto wire covers, such as split corrugatedplastic tube-looms or spiral plastic wirecovering basically any piece that dealswith mounting or speaking, awire separator is aone- or two-piece unitthat separates wiresfrom each are available intwo- to four- wire ver-sions.

8 They re installedalong the wire pathwherever wires needto be grouped plug wiremounting systems areavailable in both verti-cal and horizontalstyles. This means that,when using a systemthat runs the wiresalongside the valve covers a verticalsystem the wire group can bestacked vertically ( wire runs arestacked one atop another). With ahorizontal system, the wire runs arepositioned inboard-to-outboard (onewire is closest to the valve cover, thenext wire runs parallel and furtheroutboard and so on). Depending onclearance issues and desired appear-ance, this provides a example of very custom sparkplug wire ROUTING can be seen on anengine I recently built. I didn t wantto conform to run-of-the-mill wirerouting, and preferred to createsomething more built a custom small-block Chevyengine specifically for a street rod ap-plication.

9 I refer to the engine as asmall-block Chevy due to the basiclong-block design. In fact, this enginewas built using 100% performance af-termarket components (there s not asingle GM part in the build!).For plug wire ROUTING , the approachinvolved using a cut-to-length set of7mm MSD plug wires, routed through3 8-in. aluminum tubing. The tubing washand-bent to completely hide the en-tire length of each wire . After lightlycoating each plug wire with white lithi-um grease, they actually slid throughthe tubing without too much hide the wires at the distributorend, I chose a dual-carb aluminum aircleaner assembly from K&N. The frontair cleaner mounts in the normal fash-ion to the Holley carb. The rear aircleaner mounts to the MSD distributor,using a custom-fabricated mountingadapter. Each aluminum tube was fit-ted with a 6 tube nut and female hoseend, then flared to capture the hose24 October 2011 The wire tubes were formed to provide good clear-ance with the exhaust header tubes.

10 The SPARK plugboot end of each tube is fitted with a tube nut and 6 hose end, which is epoxy-glued in place, simplyto dress the end of the Plug wire & Hardware Engineering (DEI) Performance For You Performance SPARK plugs Distributors ( ) Performance Performance Performance 2011end. The bottom rear area of the rearair cleaner was drilled and tapped with1 4-in. NPT holes and fitted with 6 to 1 4-in. NPT fitting adapters. The tubesthen attached to the fittings ( 6 hoseends threaded onto the 6 fittings).Inside the rear air cleaner, the plugwires were then free to connect tothe distributor cap. At the SPARK plugend of each aluminum tube, I also in-stalled tube nuts and 6 hose endsthat mate flush to the SPARK plugboots (the hose ends were securedusing epoxy adhesive, giving them theappearance of being attached to theboots).