I bought some indexing washers so I can torque them to the correct spec and index them. I do not expect a big gain but between the magnacor wires, iridium plugs and indexing I hope to see some gains.

 

What engine is it??

If its the old DI 3.9 I would say that the exaust valve is at 11 oclock on the 2 cylinders towards the front
and at 1 oclock on the 2 cylinders towards the firewall... Looking at the Drivers Side Bank..
Opposite on the Passenger side..

Exaust valves appear to be the outermost valves..
This kind of makes sense as the plugs in front are angled towards the front, and those by the firewall
are pointed towards the firewall..

This is just from looking at the Rave manual..

Have a look yourself..
And see what you think..

http://www.landroverresource.com/

 

sorry, I should of specified that I have the DII with the 4.0. I have the RAVE manual, thanks for the tip.

 

You think Iridium Plugs work best Eh??

Ive got the Bosch +4's now..
Next time I might try them..

 

I think correctly indexed iridium plugs will be better than bosch +4s. Even if one of the 4 ground electrodes is in the sweet spot there still is only a 1 in 4 chance that is the direction the spark will travel.

 

honestly you would need a swirl pattern of the chamber comming up on compression. they thought up indexing when hp were junkies were dumping tones of fuel into engines to try for more power. carbs would not keep the fuel atomized and if they kept the open side of the plug "AWAY" from the incomming charge they were less likely to foul. with current fuel injection our mixtures stay atomized and burn near perfecto. also keep in ind that half of your plugs fire from the ground electrode to the center, and the the other fire from the center to the ground, not sure if this could have any effect on on indexing plugs in a DIS.so with the bosch 4's when there is wear the arc wil continue around the plug from the electrodes closest together. i personally had no luck with the things and run theel cheapo's.

Would be interested knowing if this coould have any real positive effect on fuel econ though..

 

Iridium plugs ROCK!

 

well I ordered the wrong indexing washers (tapered instead of flat) I went ahead and indexed the plugs with a marker. I am going to run it with the new iridiums for a while then swap out the washers. That way I will get a better idea how much indexing improves fuel mileage.
2 plugs are in a good location, 4 are in an ok location and 2 are in a bad location (ground electrode pointing towards intake valve).