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TR4/4A TR4 Spark Plug Recommendations
- Thread starter jimitro
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That Champion is the "stock" plug. You might go a bit colder, say the RL82YC, (new Champion number 814). Of course, lots of folks like NGKs and other brands, and I'm sure you'll hear from them! /ubbthreads/images/graemlins/grin.gif
trfourtune
Jedi Knight
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with headers you might go a little colder.if you have no indication on the plugs that you are too hot then leave the stock ones. if your timing and everything else is working properly and you are getting detonation then you may want to go one heat range colder and see if it's better. i like ngk plugs. with electronic ignition you should open up the plug gap to take advantage of the improved ignition. how much depends on your system and power.
others like alan myers may be able to give more specific info
rob
others like alan myers may be able to give more specific info
rob
Alan_Myers
Luke Skywalker
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Hi,
I swear by NGK plugs in most cars. Just the standard ones, not the fancy Iridium or Platinum or Multi-Tipped or whatever. However, I gotta say that some high energy electronic ignitions seem to work pretty well with Bosch Platinum.
The stock NGK plug for TR4 would be BP6HS. If you find any pre-ignition/pinging with that plug, due to increased compression and/or other performance modifications, try the next step cooler: BP7HS (note: other plug brands may use lower numbers to indicate cooler plugs). With cooler plugs, watch out for fouling, but there probably won't be any problem with an electronic ignition.
Incidentally, "hotter" and "cooler" plugs refer to the spark plug's ability to dissipate heat that it's exposed to in the combustion chamber. The plugs don't generate any heat themselves and the voltage doesn't change in any way. A "cooler" plug dissipates more heat, while a "hotter" plug dissipates less. A hotter-than-normal plug might be used if there is fouling from oil, for example, but is generally to be avoided. With a higher performance engine, higher temps are usually generated, so a cooler plug might be necessary.
Yes, because an electronic ignition typically provides a stonger spark than a points-type ignition you might be able to run .030 or .035" gap on the plugs. If it's a multi-spark electronic ignition with ultra high voltage, such as MSD or Mallory HyFire, the manufacturer of the ignition might have guidelines, but I've heard of folks using .045 to .050" gap. Basically, just watch out for any missing, especially above 3000 rpm. If the engine starts to miss, then the gap may be too large.
/ubbthreads/images/graemlins/cheers.gif
I swear by NGK plugs in most cars. Just the standard ones, not the fancy Iridium or Platinum or Multi-Tipped or whatever. However, I gotta say that some high energy electronic ignitions seem to work pretty well with Bosch Platinum.
The stock NGK plug for TR4 would be BP6HS. If you find any pre-ignition/pinging with that plug, due to increased compression and/or other performance modifications, try the next step cooler: BP7HS (note: other plug brands may use lower numbers to indicate cooler plugs). With cooler plugs, watch out for fouling, but there probably won't be any problem with an electronic ignition.
Incidentally, "hotter" and "cooler" plugs refer to the spark plug's ability to dissipate heat that it's exposed to in the combustion chamber. The plugs don't generate any heat themselves and the voltage doesn't change in any way. A "cooler" plug dissipates more heat, while a "hotter" plug dissipates less. A hotter-than-normal plug might be used if there is fouling from oil, for example, but is generally to be avoided. With a higher performance engine, higher temps are usually generated, so a cooler plug might be necessary.
Yes, because an electronic ignition typically provides a stonger spark than a points-type ignition you might be able to run .030 or .035" gap on the plugs. If it's a multi-spark electronic ignition with ultra high voltage, such as MSD or Mallory HyFire, the manufacturer of the ignition might have guidelines, but I've heard of folks using .045 to .050" gap. Basically, just watch out for any missing, especially above 3000 rpm. If the engine starts to miss, then the gap may be too large.
/ubbthreads/images/graemlins/cheers.gif