EF Spark Plugs and Leads - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

RedEF6 · 08-12-2004, 22:17

Hey all,

I was looking on the NGK website for plugs for my car ('95 EF Fairmont) and noted that there are different plugs for the XR6. The plug gap is the same, but the part number is different. Does anyone know why the XR6 would have different plugs? are they a stronger spark and would this be better for a standard engine?

Also I need new leads as well, and just wondering what leads people run. I was quoted $62 for a set of Eagle 9mm leads from sprint auto's, how does this compare to other people?

Thanks

Lee

stockstandard · 08-13-2004, 00:25

xr's have different heat ratings to the standard falcon plugs (like 1 degree from memory). This has to do with the slightly different design of the engines and the changes that need to be made to the design of the spark plug to ensure it stays at the correct operating temperature. I can see any reason why changing from the factory specifications would be an advantage. There are a few web sites around that explain heat ratings, such as http://www.ngk.de/Heat_rating_and_he..._nu.657.0.html

Best thing to do with prices is to ring 3 places, if they are all around the same price you are probably not getting ripped off.

Soxx · 08-13-2004, 00:53

If the engine is standard, use standard plugs.
Make sure the leads are spiral core.

Rick.

useless · 08-13-2004, 01:35

Yep I know....the xr6 plugs are a cooler plug.They are also used in lpg cars.I used the the xr6 plugs from ford a little while ago and found they made my standard 16 intech (non vct) idle a bit rougher but felt like it had better power..If you can put a cooler plug in your car and it doesnt foul up ..there is no reason that I know of why you cant..

MustangNicko · 08-13-2004, 06:27

Quote:

Originally Posted by Soxx

If the engine is standard, use standard plugs.
Make sure the leads are spiral core.

Rick.

A little off topic here Rick... I was just wondering if advanced ignition timing (EL XR6) can fk leads up? Ive allready gone through two sets of leads and a set of plugs since ive played with the ignition timing :(

Nick

Soxx · 08-13-2004, 06:41

MustangNicko -
Advanced timing has never had that effect IME, and I can't see how it could.
What brand of plugs and leads are you using?

Rick.

MustangNicko · 08-13-2004, 07:30

I was using NGK6 plugs with top gun 8mm leads. I advanced the igition timing when i put them in. A month later the car started backfiring and missing really bad. The plugs were fouled. I bought new a set of new NGK6's and it didnt solve the problem. Then i put my old leads back in and it was running sweet. 2 weeks later (around now) the car is getting the same symptons and it runs rich as all shit.

zbenga · 08-13-2004, 08:56

i need to change my leads, i have eagles on now but at just over 110km/h it starts to shudder and miss, last time it did that i replaced the leads and it went fine, i remember pulling on side of the road and poped the bonet and started reving the car and i was amazed at the ammount of crossfireing between the leads :)

Soxx · 08-13-2004, 15:24

MustangNicko -
Are the leads rubbing on something, which may be wearing or cracking the insulation?
Are they spiral core?
Maybe grab a set of spiral core leads with a thicker insulation, say 9mm or even 10mm.

Maybe the root of the problem is the richness, chase that first.

Rick.

MustangNicko · 08-13-2004, 19:00

As far as i can see they are not rubbing on anything. They were the standard motorcraft leads (i dont know if they are spiral or not) and im not sure whether the top guns are spiral either. Yeah well, the root of the problem probably is richness. Im trying to chase up the problem, im thinking i should change the fuel reg to a standard falcon one.