? About TR6 spark plugs

[01Saleen-465]

I went to change out my original spark plugs today with some NGK TR6 plugs, but the threads on the TR6's are twice as long as the originals. I am S/C and I read that the TR6's are the plugs to get. Is anyone using these plugs and ran into the same problem? Are there any clearance issues with the pistons because the plugs are an extra 1/2" into the cylinders?

 

[CJK44t]

I don't think plugs protruding much more than stock is good.

However, I am willing to bet you have later model fully threaded plugs instead of the old "straight section" style.

Put old & new side by side and compare the distance of the end of the plug and the tapered seat. I bet both are in the same location and the extra threads on the new plug fall in the straight section zone.

So both plugs should be the same overall length. Starting from the gap end, the old plug has a short section of threads, then a straight section, then a tapered seat, then the hex and insulator.

The new plug, starting from the gap end should have much longer threaded area then right to a tapered seat (no straight section), then the hex yada yada.

Better yet. Got a camera? Take a pic of both plugs side by side and post it.

 

[Kilgore Trout]

This is normal, Ford changed the recommended spark plug from AWSF (short threads) to AGSF (long threads). Some say that this is to prevent spark plug blowout.

I would not consider installing short thread plugs and I think you got the best ones for your car.

Here is a pic of the old and new recommended thread styles side by side:

 

[01Saleen-465]

Nice find on the pic. The ones on the left are the exact same plugs I pulled out of my car. So you are saying it is okay to install the longer thread style without having any problems?

 

[Kilgore Trout]

Yes, the longer thread style is now the recommended type according to Ford.

 

[01Saleen-465]

Great, thanks for your help and quick response!

 

[03ghoststang]

This is normal, Ford changed the recommended spark plug from AWSF (short threads) to AGSF (long threads). Some say that this is to prevent spark plug blowout.

I would not consider installing short thread plugs and I think you got the best ones for your car.

Here is a pic of the old and new recommended thread styles side by side:

my NGK's look like that longer thread

 

[urban96]

nice post MT, good info

 

[Dope 97GT]

yeah just replaced mine with the long thread and the guy at the autoparts store told me my piston was gonna hit the plug ...what a tool.