Nov 30, 2010 · On AC plugs, prefix and suffix letters are used to identify a specific type plus the numbers relate to thread size and heat range. R44LTS breaks out as: R = Resistor 4 = 14 mm Thread 4 = Heat Range L = Long Reach, 3/4" (19 mm) reach, (14 mm) thread fineline (which these plugs are) T = Taper Seat S = Extended Tip
Best Spark Plugs for 6.0 Chevy - Expert Review and Guide. The Chevrolet 350 is a small-block V8 engine used in standard production between 1955 and 2003. This is a performance intake manifold that will work with a vast range of applications using the 350-small block, including passenger cars...
The spark plug works as a heat exchanger by pulling unwanted thermal energy away from the combustion chamber, and transferring the heat to the engine's cooling system. The heat range is defined as a plug's ability to dissipate heat. The rate of heat transfer is determined by
As mentioned a spark plug operates in the range temperature 450 – 870°C, at 450°C carbon deposits being to burn off and if a plug may have a very black insulator nose at a lower temperature. At 870°C a spark plug will have a very white insulator nose which will blister if this temperature is exceeded and the ground electrode will melt.
However, a heat indication in one spark plug section may not produce a heat indication in another section of the spark plug. The spark plug has several sections to read to determine the engine tune-up: the porcelain, the housing ring around the porcelain, the strap or outer electrode, the center electrode shape, and the threads.
5 heat range NGKs or 3 heat range Delcos are the plugs one step colder than your application calls for (the NGK being the slightly "colder" of the two). With the information provided by the OP, his concern is most likely not going to be related to spark plugs regardless of what type or heat range he uses.
Blisters on the insulator tip, melted electrodes, or white deposits are signs of a burned spark plug that is running too hot. Causes can include the engine overheating, incorrect spark plug heat range, a loose spark plug, incorrect ignition timing or too lean of an air/fuel mixture. The spark plug should be replaced. Worn electrodes