facing spark plugs

[markmakeitso]

i've heard of people putting spacers on spark plugs so all the plugs face the same way at the same torque, usually towards the intake manifold. anybody do this to their dsm? does it help, or not until you start worrying about how many miligrams your pistons vary.

 

[RamenPride]

it's called indexing, and a lot of people running big old domestic iron do it. but, it's not going to give you that much of a gain, it's one of those every little thing adds up deals

 

[DSMSPOON]

in the end its the tuning of the vehicle that wins races, its better to face the spark plugs toward the intake valves cause you want the air to catch the spark plug as its just entered and not as its about thru the exhaust ....it effects the temps of the spark

 

[Bohrn]

yea, but with our hemispherical combustion chambers and 2 intake valves, and with the forced induction, it will be a smaller benefit to us.

If you have the time, and want to, go ahead. On the old iron, with 8 cylinders, poorly designed heads and normal aspiration, it made more of a difference. Finding the right washers might be a challenge.

 

[markmakeitso]

i'm not planning on doing it, but how does one go about indexing? do you measure the angle you'd like to turn the plug, then put in a washer in some kind of relationship like

desired angle/360=washer thickness/TPI

that the right idea?

 

[Bohrn]

its easier than that. You just take a permanent marker and put a mark on the white part of the plug that lines up with the direction of the electrode. Then you put in thicker or thinner washers so that the plug is facing the intake valve when at proper torque spec.

 

[markmakeitso]

so math isn't necessary? good deal.

 

[Bohrn]

yea, good deal eh?