Since I've been whining about the progress of my ignition rebuild the last few days, someone mentioned aligning the sparkplug gap openings with the intake valves. Just put a mark on the socket and extension where it lines up with the gap so you know which way it's facing, and tighten accordingly. Simple, but would it make a difference? Who knows. At least not noticeable I would imagine. He claimed about 3hp, but I kinda doubt that.
Anyway, anyone ever heard of this or tried it.

 

heard of.. yes... worth the trouble... No

 

Its called indexing the spark plugs. To do it correctly you have to shim the splugs, otherwise you're likely to strip the plug or head threads, or just have a plug that you'll never be able to remove.

 

I've tried it; didn't notice anything big about it. It's actually "in the air" as to where to point the gap. Some say it should be pointed at the intake valve. Some say it should be pointed exactly between the intake and exhaust. The main idea is (supposedly) to keep all your cylinders consistant with each other. This way, every cylinder gets an equal combustion.

I used the Moroso washer shims... they came in different thicknesses, and each thickness translated into a "degree" of turn. You would take your plug, and make two marks on the insulator. One mark would be, say, red, and would lined up with the gap. The other mark would be a different color, like black, and would be opposite the "gap" mark. Then you'd use these two marks to install the plug. By the positioning of the two marks (sometimes you can only see one side of the plug, that's why there are two marks made), you'd say "Hm, if it was 30 degrees counterclockwise, it would be perfect." Then you'd grab the washer that was "equal" to 30 degrees.

It takes a while to do, and is a pain. It might be worth it if you're bored and want 1-2 extra HP, but there's some problems. One; if the washer ***** on the plug and you don't notice, you'll wind up with an improperly sealed, "loose" plug. Two, by leaving some of the threads in the head uncovered by the spark plug threads, the threads in the head will get full of carbon. This could make your "next" plug hard to thread in.

A "cut" plug is one that has it's ground electrode cut down so it does not extend past the center electrode. It supposedly exposes more of the spark kernel to the air/fuel mix, and makes for a better burn. (Exactly what a Splitfire plug is supposed to do- they never claimed the spark would split in two, but people thought that's what they meant, and then they sued- give me a break!) Anyway, cut plugs might give an extra 1-2 HP, but they'll wear the ground electrode down FAST. It's not really a "street" mod, but more of a race-only mod.