Spark Plug Heat Range - V6 2.8L

my old 1970 SBC 350. I don't get too

wondering if the SAME is true for the 84 2.8L

car is predominately driven in highway

my old 1970 SBC 350. I don't get too

wondering if the SAME is true for the 84 2.8L

car is predominately driven in highway

For the cost of a set of plugs a little experimenting won't do any harm. A slightly hotter plug will more than likely make no difference in a commuting car.

...Ron

--

Selecting the correct heat range for the spark plug is a balancing act between the speed of erosion of the electrodes (wear) versus the accumulation of deposits (fouling). The correct range selection is based on a few factors:

1. Engine duty cycle. The percentage of time the engine spends warming up and at idle speed verses the time spent warmed up and at high speed .
2. How rich the fuel mixture is.
3. How much oil the engine consumes.
4. The engine operating coolant temperature.
5. Engine compression ratio and the octane of the gas it is burning. The spark plug only needs to be hot enough to stay clean. Any hotter only increases electrode wear and can contribute to preignition (pinging). Sometimes factors will cancel each other out. Any one of the following conditions can make a hotter plug the corrrect one for the application. Examples are:
6. More short trips opposed to more long trips.
7. Richer mixture in high performance setups as opposed to late model "clean" engines.
8. High mileage engines that use some oil opposed to newer engines that use almost none.
9. Earlier engines that use a 165` to 180` thermostat cool the sparkplugs more opposed to newer engines that use 195` thermostats.
10. Later model engines use a lower compression ratio for lower octane gas and have lower combustion temperatures opposed to earlier high compression engines. The platinum tip plug was 'borrowed" from the aircraft engine industry where even the coldest sparkplug would not last due to the constant high rpm and load of an airplane engine. It can do both jobs. It allows a very hot plug to be used in a car engine and still have very long electrode life. This means that the plug can be hot enough for a car that will be used for very short trips where the engine never reaches operating temperature or constant highway speeds that would wear out a conventional plug in short order. In short: You can use as hot a platinum plug as you want as long as the engine doesn't ping. You can use as cold a conventional plug as you want as long as the electrode doesn't collect deposits.