98 RANGER

I have a 1998 ford ranger and i would like to know if anyone can tell me why i have 8 spark plugs. I know it cant be 2 plugs per cylinder. I have a 2.5 liter 4 cylinder engine. Please can somone tell me why. is this odd or normal? Thank You

thefonz

4 cylinders- 2 plugs per cylinder, 1 each for intake side 1 each for exhaust side. Screwy huh!

98 RANGER

Thanks. It Is Pretty Screwy

Johnny Mullet

Yeah, one of Ford's better ideas.

Brandon77

Yeah, especially when some mechanics dont even know it..i once asked for spark plugs and was given 4, and at the time did not know that there was 8...pretty disappointed when i popped the hood lol.

mre_power

i had a nissan pickup that had sparkplug setup.

frtendtim

Anyone know why Ford went with that setup? I know a buddy of mine had that on his Ranger, he was surprised when I told him he needed 8 plugs.

Mort

4 for the cylinders and 4 for the starter

Johnny Mullet

They were actually designed to spark right after each other for burning all fuel from the combustion chamber.

Pinhead

It helps to completely burn the fuel, and since the flame front starts on both sides and converges in the middle, it'll burn in half the time of a normal 1-plug chamber. A fast burn is good.

Compare a cross-bow with a compound bow, each with the same pull weight. The compound bow will out shoot the cross-bow every time, since it exerts 99% of it's power in the first three inches or so of the throw. An engine works the same way. You want peak cylinder pressure to be developed at around 14-15 degrees BTDC. Also, the less ignition advance you can get while still putting the peak pressure at the right spot, the less the piston has to fight the expanding air before top dead center, thus making the engine more efficient.