Hello, planning on changing my plugs this weekend and trying to sort some things out. Owners manual says 14.4 lb ft but to put some graphite grease on first. Most sites say using grease/anti-seize increases applied torque by 30% Spark plug maker, NGK, says don’t use anti-seize on any new plugs unless manufacturer says to (lots of debate about pros and cons of using anti-seize online). So, what is the consensus? 1) Do I use anti-seize and torque to 14.4 lb•ft as owner’s manual says, even though this would likely be 18.5 lb•ft due to 30% increase which is the lowest torque recommended by NGK for this plug. Or… 2) Do I use anti-seize and torque to 10 lb•ft taking into account the 30% increase in torque applied trying to get to 14.4 lb•ft of applied torque. Or… 3) Do I use no anti-seize as it’s “baked into” the plug already and torque to 14.4 lb•ft. Or… 4) Do I use no anti-seize and torque to 18.5 lb•ft Thank you for your input. Mark Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
No anti-seize finger tight and then another 1/2 to 2/3 turn with the ratchet. New plugs have a crush washer. Very simple...no need for a torque wrench...
In the tradition of providing conflicting internet advice... Many years of wrenching and I have found a fair number of sparkplugs/Aluminum heads to be partially seized. So I would recommend you follow Ferrari's instructions and use a lubricant. I use antiseize with sparkplugs/AL heads though, like Dockboy, I don't use a torque wrench, I tighten essentially per the NGK instructions. If you prefer to use a torque wrench, the difference between graphite grease (per Ferrari) and antiseize re torque setting is not enough to matter.... A general guideline that works well in the automotive world, though probably NOT for spacecraft(!) is reduce the torque by 25-30% if using any lubricant when the torque spec is for dry threads. FWIW, pretty much anything applied to threads is a lubricant when assembling - including thread locker.
Thanks for those replies. I was a bit concerned due to hearing horror stories of torquing too tight and cracking a plug, or under torquing and popping one out stripping the treads and the inevitable head repair. Wasn’t sure if I should interpret the Ferrari owners manual word for word, meaning MUST use grease and then MUST torque to 14.4 lb•ft which would actually be 18 dry. Just wanted to know what others do/would do. Thanks again.
Here is the part of the 308GT4 WSM that covers spark plugs. Image Unavailable, Please Login Sent from my iPhone using FerrariChat
