facing spark plugs towards the induction charge

[djezd]

I saw carbibles discuss this and i have a couple of questions

a) is it worth it?
b) cylinders 1,2,3 and 6 are spot on 4 and 5 are ~ 130 and -90 degrees away from where they should be, in my mind, to be facing the charge, i.e. pointing up towards the valve.
c)where do you get these 1/4 turn crush washers?

cheers

[smithy318i]

As far as i know, the plug fork should be on the oposite side to the exhaust valve.
you can tell this by the discolouration on the white insulator.

I have no idea if it makes any difference though.

[Templ8e30]

Crush washers only come on new plugs.

Might make a difference in F1 or top fuel drag racing, very doubtful it'd make one iota of difference on a road car.

Cheers,

Iain T

[djezd]

That was what i was assuming, but seen as i was putting them in thought it would be interesting to see where the 'fork ends up facing.

Looking at the valve gear diagram on realoem it appears that there are 6 pairs of valves on a 12V, which i have, rather than 12 valves in a row, so that would mean the fork when facing up does indeed get the induction charge cloud straight in the open side. However, the valve must cause massive turbulence...which presumable would mean that the charge does not necessarily directly 'blow' into the spark plug gap!

So i'll be leaving them as they are!

[Martinaston]

At a guess its totaly pointless, once the valve closes and the piston rises the mix gets compressed anyway so it surrounds the plug. You'ed be hard pressed to notice any difference especialy on an M20

[Turbo-Brown]

Think you'd need to fiddle with every set of plugs you fitted as the start of the thread isn't likely to be linked to the position of the electrode when they make them, they'd most likely just weld the electrode on arbitrarily.

[djezd]

The NGK one's i just put in where at least welded in at 60 degree intervals as they all where in line with a point on the hex nut, i did not look to see if the helix opened at the same point on each.

[Turbo-Brown]

Would probably make sense for them to hold the plug by the hex when the electrode's welded on.

Guess the other thing would be the random start position of the thread in the head.