Hi All
I was looking at a 02 Ranger last week and I thought it only had four plugs not the eight I expected? Did Ford go back to a 4 plug system at some point or was I just missing the other four?
Thanks
WB

 

The 2.3l and 2.5l Lima 4cyl engines use dual spark plugs from 1989 thru mid-2001 in Rangers, so 8 spark plugs, this added more power
The 2.3l Lima was first used in a 1974 Pinto, then in quite a few other Ford models as the "go to" 4cyl engine, it used a distributor and 4 spark plugs thru 1988
2.5l was a "stroked" 2.3l and was only used 1998-2001 in Rangers/Mazda B2500

In later part of 2001(mid-year) Ford Rangers got the 2.3l Mazda L engine, Ford renamed it a 2.3l Duratec in Rangers, it has 4 valves per cylinder so even more power, and no room in the head for dual spark plugs


Dual spark plugs have long been known to add more power to any engine, problem was distributor lay out, both spark plugs MUST FIRE at exactly the same time or no benefit, hard to do with a distributor spark system
Example of a 6 cyl dual spark plug distributor cap: https://cdn2.pelicanparts.com/catalo...53-015CW_1.jpg
Need dual Coils as well
And head space, got have room in the head for a 2nd spark plug and have to be able to get to it to change it, which is hard on V6 or V8 engines, although Dodge Hemi did have dual spark plugs for a few years

When 2.3l Lima went to Distributorless spark system in 1989 it also got the dual spark plugs because head space was available and it added a bit more power without much engineering

4 valves per cylinder added even more power and was a better use of head space

On airplane engines dual spark plugs added more power but also having TWO separate spark systems made them more reliable, usually both spark plugs are only used in take off and landing, when flying one was switched off and then alternated during a longer flight, to make sure both were working

 

Thanks for the info Ron
So if I understand it right if I can find a 2002 or later 4 cyl it should be a 2.3L Duratec with just the four plugs and one coil pack?

Thanks
WB

 

Yes, 2002-2012 Ranger used 2.3l Duratec 4cyl

But the 2002-2003 also have IMRC(intake manifold running control, Google it, lol) and heated thermostat
These were dropped in 2004-2012 models and they have more power