E-etc Spark Plugs

mdt · 06 April 2007, 16:18

Q: Dose it matter which angle you put in spark plugs into an e-tec motor?

Have just got these plugs to put in and was told they have to have the black (felt-tip pen) marks lined up. I did ask the parts guy, but alas he did not know as he only did parts and the workshop guys where not in.

I can’t for the life of me see how it could matter but….. can any one shed some light on the apparent dark art of e-tec spark plug fitting?

jyasaki · 06 April 2007, 16:23

That's a process called "indexing".

Basically, it means putting the spark gap opening pointing towards a certain point of the combustion chamber (or rather, putting the part of the spark shielded by the electrode pointing the other way.)

Don't know if it actually makes a difference or not; the manual should say if it's necessary for your particular motor.

jky

mdt · 06 April 2007, 16:28

Quote:

Originally Posted by jyasaki

Basically, it means putting the spark gap opening pointing towards a certain point of the combustion chamber (or rather, putting the part of the spark shielded by the electrode pointing the other way.)

makes some sence. I take it then that the electrode is to point to the wall? will take the old ones out and count the turns and see what one can do about putting the new ones in the same.

Quote:

Originally Posted by jyasaki

Don't know if it actually makes a difference or not; the manual should say if it's necessary for your particular motor.

I know what you are saying as I really can't see how it could make that much (if any difference)

thanks for the supper quick reply and info.

jyasaki · 06 April 2007, 16:31

Quote:

Originally Posted by mdt

makes some sence. I take it then that the electrode is to point to the wall?

Don't really know. If the plug is centered in the cylinder, I'd guess the opening should point towards the intake valve. If the plug is off-center, I'd guess point the opening towards the bulk of the chamber.

Wild-ass guesses, though.

Quote:

thanks for the supper quick reply and info.

No problem. It was the first unread post when I logged on.

jky

mdt · 06 April 2007, 16:34

Quote:

Originally Posted by jyasaki

Wild-ass guesses, though.

That is about as good as one can exspect. will go with this

The Jackeens · 06 April 2007, 16:53

yo,

heres an extract and link which describes whats needed .

"E-TEC engines require the open gap of a sparkplug to face or to be within about 90° on either side of the injector tip for best drivability.
The following link shows which plugs to use and how to identify 1998-99 FICHT heads, and the second part shows the tools needed and the indexing procedure.

Even though the E-TEC is not mentioned in the article, the indexing is performed the same way."

and the link is
HERE

there also a load of other info on the main "setup site"

hope it helps

118118 · 06 April 2007, 21:25

the electrode is ment to go towards the the injector, deflecting the petrol as it is injected......

but
not all plugs will fit evey hole, tightening in the right place..... kinda lucky dip.

Chris Murray · 07 April 2007, 19:00

I understand that if the plug gap does not fall within the 90% zone, then you should use a different plug.

I have yet to change the plugs in my "250" but this is what the engineers told me.

Chris.

MarkM · 07 April 2007, 20:25

Put all 6 plugs in, handtight. See how you get on with the positions. Change the plugs if necessary. When they all are in the correct position, start with the wrench. There is no way back if you turn them to far.
The picture below is very important.

TIM · 09 April 2007, 20:57

Indexing makes a huge difference...... recommended...... it makes about 200rpm difference on a engine in my experience, and try to line them exactly.