Spark plugs?

[trogdor4x4]

I changed out my plugs to the stock replacements r43 delco. The truck has less pick up and go than it did before. Should I try another, if so which one? What is the difference between the r43 and the r45? /forums/images/graemlins/ears.gif

 

[big83chevy4x4]

2 heat ranges. the r means resistor plug. the 4 means the thread and the 5 means heat range. i think it is a cooler plug, i know with the ngk plugs the bigger the number the cooler the spark

 

[trogdor4x4]

what is the difference between hotter or cooler plugs, is one better performance than the other? is one better fuel efficiency?

 

[big83chevy4x4]

the hotter the plug the better the spark. its like having a weak spark, not very powerful, bad gas milage. i use it on my bike as a fine tuning of the carburation. the same for the trucks. if it is running a little rich go to the next heat range, if it is running lean, drop down a heat range.

i would put the r43 back in. i run a r45ts on my stock motor

 

[84_Chevy_K10]

Heat range has nothing to do with the strength of the spark.

Heat range has to do with how much heat the electrode tip retains.

Too hot a plug can cause preignition because the electrode stays too hot and ignites the fuel mixture before the actual spark. This can cause very serious engine damage.

Too cold of a plug will just foul out.

The reason a colder plug is recommended for people with detonation problems is pretty self explanitory with the above information. Hotter plugs are typically used if you're fouling lots of plugs. Keeping the electrode hotter helps it clean itself.

No biggie as this is a commonly misunderstood thing about spark plugs.

 

[k20]

wait a sec, i thought a higher second number was a hotter plug, not the other way around......atleast on ac delco, i have r45ts's in mine, was told thats the hottest plug they have, but they have r43ts etc. Do i have the coldest, or hottest plug? If i have coldest would probably explain why i keep fouling plugs and possibly why my engine always seems to be running rich.

 

[big83chevy4x4]

i know for a fact that the NGK plug the lower the number the hotter the plug. not sure on the ac but i would assum its the same.

 

[75-K5]

So let's get this straight, if you're running too rich, you need to get hotter plugs?

 

[k20]

from how i understand it, but for me atleast it would just be a patch, i have some otehr reason im runnin rich as a monkey.

 

[84_Chevy_K10]

[ QUOTE ]
So let's get this straight, if you're running too rich, you need to get hotter plugs?

[/ QUOTE ]

If you're running too rich, you need to lean out your fuel mixture. Hotter plugs might band-aid the situation and stay cleaner with that overly rich fuel mixture, but the tradeoff is potential preignition which could cause serious engine damage.

I'd say fixing your carb or replacing an O2 sensor is easier than fixing a piston with a hole in it.

 

[75-K5]

Yeah, I know it would be a band-aid. I just get squeamish at the concept of spending a hundred bucks or more on a carb when I can get a new one for a few bucks more.