B
Bullitt
Guest
I ran into this website of engine building Q&A. Granted, this guy is running a buisness and is giving his opinion based on his background, but I like his no-nonsense attitude. For example:
Here's the link to his site: BA Tech Tips.
--Bullitt
Q: Do those fancy split tip sparkplugs really work?
A: No. Electricity follows the path of least resistance. It has nothing to do with a split tip or a fancy U groove! The sparkplug does one thing only. It acts as the grounding source for the ignition and that's it, period, end of story. The only difference with a sparkplug is that there is a gap in the current path. The size of the spark is dictated by the voltage and amperage output of your coil and the output of your coil is dictated by the saturation (dwell) time of your ignition system. You'll hear claims like, "it made more horsepower" or "I got better gas mileage". Well of course they did! Their engine needed a tune-up or they wouldn't have tried the new plugs in the first place! Any engine would get better gas mileage and more horsepower after a tune-up!
What split tipped plugs can do is promote pre-ignition and/or detonation. How? Try this, take a hanger and try to heat it up with a cigarette lighter. Oh yeah, it gets hot, but not hot enough to glow cherry red. Now take a paper clip and heat it up with the same lighter. It gets hotter faster and glows cherry red! It's simple, it takes less heat to heat-up smaller objects. What do you think those tiny little pieces of split tip electrodes are doing in your engine? Now add more compression and heat (a race engine) and they act like a dog gone glow plug... detonation... ka-boom! Just about in that order.
Solid lifter cams are always a good choice for a hot street or race engine. They usually have faster ramps (lobes) than hydraulic cams but not as fast as roller cams. They also usually need a stouter spring than a hydraulic cam but not nearly as stiff as a roller cam. They're kind of the middle of the road between the two. Forget about those lame wives tales about solid lifters always going out of adjustment! That's just not true! The ONLY way the adjustment (lash) can change is if something is either wearing out or going bad, period! If a rocker stud starts pulling out, the lash will increase. If the tip of the valve is getting hammered or mushroomed, the lash will increase. That's what lash caps are made for. If the tip or the cup of the rocker arm starts to wear out, the lash will increase. If a push rod bends or wears out one (or both) of the tips, the lash will increase. If the lifter is getting cupped or the cam is going flat, the lash will increase. If a valve seat "sinks" or recesses, then the valve is actually lifting or sitting higher, the lash will decrease. No matter how you slice it, if a solid lifter cam keeps going out of adjustment, something is seriously wrong! Most of the time it was just a wives tale being spread by someone who's probably never even ran a solid lifter cam or had a piece of junk engine that was falling apart.
Here's the link to his site: BA Tech Tips.
--Bullitt