Found something interesting about AC Delco Iridium Plugs

[EZ-E]

I just happened to be doing a freinds Gran Prix, changing out the old plugs and wires for new and well low and behold they are Iridium plugs.

 

The real kicker of it all is that those plugs are made my NGK!!

 

I was wondering though, they are the same size, thread and all, but, they are a tapered end and not a gasket style end.

 

Would these work with the Datsun L6? or would it have to be a gasket style plug?

 

Found it interesting to say the least that Delco plugs were made by NGK, and the cost is only 5.99 compared to 12 plus.

[Tony D]

Taper Seat Plugs are a no-no on an aluminum head meant for crush gaskets.

Deformation of the seal area, and the first thread in the head is almost assured.

 

They will probably seal, but chances are they will damage the head...

[EZ-E]

Well there goes a cheap alternative to the NGK iridiums, maybe they have a iridium type with the crush gasket.

 

Thanks for the reply Tony

[Cody 82 ZXT]

Well there goes a cheap alternative to the NGK iridiums' date=' maybe they have a iridium type with the crush gasket.

 

Thanks for the reply Tony[/quote']

 

 

Ngk makes Iridiums. I've bought them for my Z before. 5.99 or 6.99 can't remember which.

[blueovalz]

I've interchanged between flat and tapered plugs, and yes, the tapered ones slightly deform the seat (and adjacent first thread), but once you remove the plug, the last thread is returned to normal. You don't want to cinch down hard on the tapered plug, just snug.

[zredbaron]

five years later... BUMP! haha.

 

it's my understanding that iridium plugs / platinum / fancy coating x is more for longevity than ultimate performance.

 

that is to say, that you would get more miles out of an iridium plug, but right out of the box, a "simple" plug such as the bosch super plus would perform the best (until xxxx miles, after which point the iridium plug would outperform). this is because they are more resistant to corrosion / carbon buildup, but straight copper conducts better. unfortunately copper loves corrosion... just look at pennies or the statue of liberty.

 

similarly, cheap break pads will stop you in a shorter distance and are less prone to locking up than carbon / fancy material x pads (assuming NOT from high speed and NOT repeated braking, both of which will find heat fade with a quickness).

 

not what you might think!

[jasper]

Spark plugs......lots of how and whys...start reading........

First and foremost....Fit

 

Correct thread, seat, and length. If it doesn't fit right, you fail.

 

Second.......HEAT RANGE!!!!! If it's wrong, it runs like ****, or you break/burn something, can be very BAD ( holes in pistons, etc).THE most primary concern , after fit.

 

Copper, Iridium, paladium , etc, etc. Mostly longevity related. (NOTHING TO DO WITH CORROSION). RATE OF WEAR OF ELECTRODES, (not very important).

 

Start with the book/manual suggestion, then alter ( heat range) to suit ( learn how to read plugs)

Good Luck.........ART & SCIENCE

Edited April 4, 2010 by jasper

[vantage]

Iridium/paladium/platin plugs are so called "fine tip" plugs, and help considerably with lowering the spark voltage for the initial spark due to the finer tip.

Longevity is a feature you get with the precious metals used, but the main point to use fine tip plugs is that they help a lot with cold and warm start, even when running considerably lean or rich. They don't add performance even if marketing would like you to believe you this.

 

I recommend NGK BPR6EIX if your 240Z has points or a transistor based ignition (280Z/E12-80, HEI, Pertronix etc), the difference in starting or running cold is noticable.

Do not use fine tip plugs with an MSD or Crane box, the additional power of the CDI box just eats up the fine tips and with a CDI ignition you don't need fine tip plugs anyway.