spark plugs

[4whler]

Just got back from parts store with plugs and wires and they gave me r43ts,always used 45ts. Are these ok with a 350 and holley pro inj. Did a search all I can find is the gap.

 

[SUBFAN]

I you have always used something else and they work fine, go back and trade them....

Learn how to read the plugs, and adjust the heat range a bit if necessary....

 

[Beast388]

The number in the AC plug designation is the heat range. An R43TS is a colder plug than a R45TS. Do as SUBFAN suggested and learn how to read the plugs. If the engine is stock, then use the factory recommended plug and go from there.

FYI....here is a definition of Heat Range

"Heat range refers to the spark plug's ability to transfer heat from the tip of the insulator into the cylinder head. In order for a spark plug to perform satisfactorily for more than a few miles, it must be of the proper heat range. If a plug is too hot, it will cause pre-ignition, and can burn the center electrode completely away. If a plug is too cold, it will have a tendancy to foul and misfire, reducing horsepower" (Small Block Chevy Performance)

My old 350 liked R43TS's but my 388 with the same heads, likes the R44TS's. /forums/images/graemlins/thumb.gif

 

[boggerless]

i had to run r46ts in my old engine because# 8 oil fouled so bad.and i would still have to swap it with the #1 cylinder every four months. /forums/images/graemlins/grin.gif /forums/images/graemlins/k5.gifto /forums/images/graemlins/truck.gif

 

[4whler]

Thanks for the FYI learn something new every year.

 

[dyeager535]

Actually, to be nitpicky, the last numner is the heat range, the first number is thread size. (4=14MM)

But for the heads we deal with typically, the 4 is a constant anyways.

(R=Resistor, 4=thread size, 5=heat range, T=tapered seat, S=Extended Tip)