SPARK PLUGS

[hotrodharley]

i was recomended ngk -9 plugs for my tune-up from serval different racers on some froums i go on;;;RBS has killer deal on -10 ngk's..what's everyones thoughts on going from -9's to 10's?or should i stay with the -9's?if i go to the -10's what changes think i'd need to do;;haven't made any passes on the -9's so don't have a plug reading;;i put my eng specs on the fourm's and -9's was what most suggested me to go with;;I need to buy plugs ASAP;was having plugs reached to me to reinstall in car and they dropped 2 of them on the floor so i'm affair to use them for test n tune..not sure if they got cracked when dropped and Iknow that would be bad news if cracked and try to run car with them so need to buy new plugs to be safe then sorry;;

[dreracecar]

I have been running standard B9ES for 20 years 1 set per year and leave them in all year. I Dont beleive in any "warm-up" plug nonsense

[masracingtd1167]

I have been running the 10's in mine and they have worked very well for me but I would like to try the 9's at some point this season . Mine is injected alcohol . I would be interested in what you other guy's are doing . Another thing is Timing . I run 36 degree's in mine and some people tell me that is too much . They tell me that I would be faster if I ran 28 to 30 . Bill 

[ricardo1967]

Here's a previous thread on the topic:

Best heat range spark-plugs for methanol
http://www.frontenginedragsters.org/forum/index.php?topic=670.msg4246#msg4246

[32bantam]

They will both work to make the engine run. The difference is they way they get rid of the heat. The 10 plug is colder...it dissipates heat into the head better so it may not "color up" the same as the 9 which is hotter. If you are trying to find your tune-up and are on the edge ...the plugs are your window to what is happening in the cyl. (that is a whole topic on its own!) If you have a good safe (not lean) tune up the 9's and 10's are interchangeable.
Steve

[32bantam]

I was just reading an post by Mike Canter...the guru of plug reading!....he noted that the longer center electrode will be hotter BUT the outer shell will be the same in both. So NO real difference in Alky and reading the outer shell for the tuneup.