koolrayz

iTrader: (26)

I was looking at the TR7 & TR8 plugs I have at home. The TR8 are boxed as #7317 R5724-8 The TR7 are marked #3346 BR7EF.

The TR7 electrode barely extends past the base of the threads, no porcelane extends past it. On the TR-8's the tip protrudes much further out than the TR-7's?? When I hold the TR6, 7, 8 all together the 7's look to be by far the coldest plug. I thought the colder the plug the less protrusion????

Beaflag VonRathburg

iTrader: (176)

I'm no expert on plugs, but a TR8 is a colder plug than the TR7. There's been talk in the nitrous section a lot about plugs. You might want to look around in there.

XtraCajunSS

iTrader: (2)

TR8 is colder than TR7.

Shane

koolrayz

iTrader: (26)

That doesnt answer the question of why a plug with a colder number (TR8's) protrude further into the combustion chamber than the TR-7

Sales2@Texas-speed

iTrader: (5)

The longer reach into the chamber does not make it a colder/warmer plug. The reason one is longer than the other here is that they are different series (the numbers before and after the heat range dictate reach and such of the plug). The heat range is dictated by the length of the insulated nose, which you can only see very little of without cutting the plug open (see page 2 of link below)

http://www.ngksparkplugs.com/tech_su...x.asp?mode=nml

There a little info from NGK on the subject.

koolrayz

iTrader: (26)

Now I got it thanks thats a great link

Sales2@Texas-speed

iTrader: (5)

Glad to help!