ir3333
Well-Known Member
.how do you decide which heat range to use?
i.e. what changes would require a hotter or colder plug?
i.e. what changes would require a hotter or colder plug?
spark plugs
- Thread starter ir3333
- Start date
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What engine and combo? I rebuilt my HP 273 a couple years ago and thought I'd try some Autolites. Big mistake! It never did quite run right and I could never figure out why. A motorhead customer of mine suggested going back to Champions and trying a heat range or two hotter than the original plug. (mainly because of around town cruising and lower than stock compression) I did that and it runs like a different engine. Let us know what your'e running. tmm
ir3333
Well-Known Member
..pretty typical '70 Duster build.
340, L2316-30, X heads, XE-268,manifolds, 2 1/4 duals, LD340, 650 thunder,dynamic converter
RN9YC,thinking of going a bit hotter to RN12YC ?
340, L2316-30, X heads, XE-268,manifolds, 2 1/4 duals, LD340, 650 thunder,dynamic converter
RN9YC,thinking of going a bit hotter to RN12YC ?
Stock heat range will do it for you. Now IF you take it to the track, you could try a range cooler. Racers or more Concerned with this.
Yep! I started with the n9y's but the 12y's worked better. You can put the 9's in and take your car for a nice drive and bring it back home and read the plugs. If they are a bit black and sooty you need a range or 2 hotter. If they are grey colored you should be ok. This is the best info I've found about heat range.
[ame="http://www.youtube.com/watch?v=fiMM2S0aADM"]SPARK PLUG READING - YouTube[/ame]
Knowledge is power! tmm
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