Spark plugs for 147

[bendover]

I have been looking on the NGK website for plugs. It says there is only one type of plugs needed.

The hand book says there two distinct types, why is this.

Since i had water in one of the pots, i think its time to change. I have noticed that both Denso and Champion also do plugs for Alfa,s, but they too say only one type of plug is needed.

Can anbody advise what is the best plug to use and why.

[colcol]

From what i have seen, the only type used in the twin spark and JTS is NGK, so go with them, sometimes the two types of plug will be standard, [cheap] and platium, [dearer], and the platium plugs last longer than standard plugs and are fitted to cars that are a pain to change the plugs, in the JTS and twin spark, the plugs are easy to get at, as they sit on top of the motor, and the NGK are more common and easier to get, Colin.

[bendover]

So really the only dif, is one is platinum and the other isnt, is that what i read.

Not really sure why thats done, would it make a dif to have all platinum or all none.

[colcol]

I know that with some front wheel drives with V-6's for example, the three back plugs are platium and get changed infrequently and the three front plugs are standard and are easy to get at, so they get changed more often.
Sometimes when cars have covered a lot of klms, they use a hotter plug to burn off all the oily deposits, so that they don't misfire due to a dirty plug.
Just put back whatever plug type you are using, Colin.

[Cool Jesus]

The twin spark uses two different sized plugs (4 large / 4 small) I think the smaller ones are only a 10mm diameter thread from memory. Both are a 16mm socket. Don't skimp on the plugs, they last 100K kms and from what I've read on forums, owners do notice a difference in performance (me included). Torque them to spec, 12Nm if I'm not mistaken for the larger plug and less for the smaller plug, it's not tight whatever it is. You can get them as a set of 8, but for the platinum a your looking at about $15 a plug.
Alternatively, to just get the service done on a budget the cheaper plugs could be got for half the price.

[bendover]

Thanks guys, most helpful. I dont have a torque wrench and honestly, i have never used one.

[Cool Jesus]

That's ok, wouldn't hurt to put that on a wish list though. You are dealing with alloy engines and it can mean the difference between components loosening, stripping threads or seizing threads also. Be mindful of the sump plug, it's a low torqued item and can be a major PIA if it's seized. He'll I torqued my sump plug and found the the daughter had scrapped the bottom somewhere hitting the plug. Having snapped an Allen bit, then rounding out the Allen socket I finally got it with Stinson and an extension bar. Failing that was to weld a socket head on the damn thing. Don't quote me on the torque for the plugs, but they are virtually just nipped into place. Actually I have a torque wrench that starts at 20ft/lbs and I find most of the servicing components require less than this which is basically nipped, just a bit more than nipped and a bit over that again.

[colcol]

The torque wrench settings for 33 plugs is about 25lbs, the 156 is about the same, if you are going to get a torque wrench, get one that starts at about 10lbs and goes up, its the low torque things that you tend to strip, tools these days are so cheap, compared to the olden days when i was an apprentice, Colin.