Spark Plug
Road Master
Joined: Apr 2009
Posts: 1,123
Likes: 43
From: NJ
Are screamin eagle plugs iridium?
once the centre electrode has lost its square profile
Ds
Seasoned HDF Member
Joined: May 2008
Posts: 21,220
Likes: 12,811
From: South Carolina
I guess if you are using those old AC45 spark plugs you would need antiseize....
But most manufacturers put a sacrificial coating on the threads to prevent the plugs from sticking in the heads.
http://www.ngksparkplugs.com/pdf/tb-...1antisieze.pdf
But most manufacturers put a sacrificial coating on the threads to prevent the plugs from sticking in the heads.
http://www.ngksparkplugs.com/pdf/tb-...1antisieze.pdf
Seasoned HDF Member
Joined: Dec 2010
Posts: 7,736
Likes: 1,524
From: Coromandel Peninsula New Zealand
I did 120K in my Nissan Maxima and never even looked at the (iridium) plugs...also, I just took a genuine H-D brand plug out of a TC and it took the thread with it....maybe H-D don't use the sacrificial coating...I helicoiled it put NGK Iridiums in and used anti seize.
Seasoned HDF Member
Joined: May 2008
Posts: 21,220
Likes: 12,811
From: South Carolina
I`ll admit that I always used to use anti seize on plugs.
Two of my cars have 4.6 Ford engines, which have been known to spit plugs out of the head, when I did some research into it I found out that antiseize was discouraged due to the issue of over torquing the plugs.
Probably not a big issue on a HD engine, they seem to have plenty of threads, but some car manufacturers are pretty skimpy in that area (some of the early ford 4.6 engines have 4 threads
...)
Two of my cars have 4.6 Ford engines, which have been known to spit plugs out of the head, when I did some research into it I found out that antiseize was discouraged due to the issue of over torquing the plugs.
Probably not a big issue on a HD engine, they seem to have plenty of threads, but some car manufacturers are pretty skimpy in that area (some of the early ford 4.6 engines have 4 threads
...)
HD Forum Stories
The Best of Harley-Davidson for Lifelong Riders
Jason Momoa Is Turning Classic Harleys Into PHEVs
Verdad Gallardo
Harley-Davidson Fat Boy Becomes a Dark, Decepticon-Inspired Custom
Verdad Gallardo
6 Weirdest Harley-Davidsons Ever Sold to the Public
Verdad Gallardo
7 Times Harley-Davidson Chucked Tradition Out the Window
Verdad Gallardo
7 Surprising Harley-Davidson Products that Are Not Motorcycles
Verdad Gallardo
8 Best Harley-Davidson Motorcycles Ever
Pouria Savadkouei
10 Worst Harley-Davidson Motorcycles Ever
Pouria Savadkouei
Killer Custom's Jail Break Is The Breakout That Refused to Blend In
Verdad Gallardo
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?
Verdad Gallardo
Grand HDF Member
Joined: Mar 2007
Posts: 4,923
Likes: 266
From: Deep in the heart of New Jersey
When my current plugs ever need replacing I'll try the iridium plugs. At this point it may be a while.,,
Seasoned HDF Member
Joined: May 2008
Posts: 21,220
Likes: 12,811
From: South Carolina
200 bucks labor was a no brainer.
I changed the plugs in my Merc Grand Marquis at 150k, they were running fine, but I worried that 8 years was a long time for plugs to be installed in an aluminum head. Standard Motorcraft plugs looked fine, they would have lasted the life of the car I think (now at 240k).