You all might think im crazy, but hear me out. I was watching a tape on engine performance at school and they were showing that by facing the spark plug towards the intake valves will create a better explosion thus giving you a bit more power. The guy in the tape marked where the spark plug gap is, forgot the correct term, but facing the gap towards the intake valves and the explosion becomes better. I haven't tried it but he claimed on F/I car they can gain 10hp, and on N/A car about 2-5hp. I know its not a lot but it does give a better power stroke. Here's a pic to better describe what im saying.



Also from what my teachers have said new cars like the Acura TL, have them put in this way to make more power. Tell me what you guys think...

 

Indexing. Been around since engines have been using sparkplugs. But I don't know if it benefits our engines. Remember we have 2 intake valves. Well except for the VG boys.

 

that and I've read (thus, take with a grain of salt) that most import engines and plugs are designed so that the plugs are indexed properly when they are torqued to spec... they cut the threads in the head and make the plugs so that once torqued, they're in the proper position..


dunno how much truth there is to that, but it's easy to see it happening w/ today's technology.

 

Thanks guys, I thought i was going to get flammed. I asked other teachers about this, they said its worth to do, better power stroke and the engine will be more responsive. The one guy said it might give 3+ hp in a N/A motor. I know 3hp isnt a lot but its better to say you have 200hp than 197 hp. And Thanks you guys for telling me the correct word.

 

What about indexing with the "bosch platinum 4" jk

 

gaps between the grounds

 

slightly but it's not enough to really go off, doesn't really matter with these engines though but you already knew that

 

You wont get 3hp on a dyno from these engines indexing. It's more common on old engines with distributors and points. I still do it to keep things uniform but thats more just habbit than anything. Easiest way to tell really is to just put the sparkplug in the socket, them mark the extension so you know exactly what way it is facing.

 

I have a theory on indexing in the opposite direction for Nitrous engines. Keep the electrode further away from the exhaust flow to perhaps protect them more from being melted off.

 

I can't say if Nissan attempts this on their engines but I can say, from experience, that it doesn't work out. I doubt the spark plugs are all die cut starting from the same clock.

I did however manage to end up with one batch of plugs that indexed within a 90º sweep (thats within 45º of spec for you math impaired). I only had to relocate one or two of them. And I don't use shims.

 

excuse the ignorance, but ive read the thread and i dont understand half the point og indexing, how would you know when the spark plug would be facing the intake valve? idk i think i confused the crap out of myself!

 

On a maxima motor it's very easy to locate the intake valves. Look at where the exhaust exits, towards the front and rear of the motor, the intake manifold is in the center so the intake valves are in the inner part of the motor and exhaust valves are the outer part of the motor. (lookin at it from front to back).

Well I was thinking about it again, my teacher said to mark the spark plug, but how in the world will you see it in those tiny tubes?! SO i figured place the plug on the socket then mark a line going straight up the socket indicating were the electrode is facing.

 

im gonna have to try this when i get my new ig coils in play.