I took a look at my friends 2.3 ranger and to my surprise it 8 spark plugs, one on each side of the cylinder. I have never seen that before. Can someone tell me what the purpose is. The only thing I can think of is better fuel efficiency. Thanks.
Dan

 

I had an 82 Datsun 4 cyl with 8 plugs. It was to clean up the emmissions for U. S. sales.
The same engine in Europe had only 4 plugs.

 

yeah one set fires a little while after the other set, it is just to clean up the emissions like was said.

 

It had the little LEV sticker on the driver's side glass too. Low Emissions Vehicle. As aforementioned, it's to help complete combustion in the chamber and thus, reduce the output.

 

I just sold my 1990 ranger xlt when I bought my SCrew. It had the little 2.3L 4 cylinder with 2 plugs per cylinder. After 30,000 miles I would take it to get a tune up and the plugs (all 8) still looked brand new. So I guess it made it easy for the plugs as well as cleaned up the emissions. The down side is you had to pay for an 8 cylinder tune up.

cajun

 

My 91 Mustang was that way it added a few extra horse power when they went to the 2 plugs per cylinder as it was rated at 105 hp and the 90 4 banger Mustangs were rated at 88hp.

 

People do it to motorcycles too. I've seen a Harley with 2 plugs per cylinder

 

My Dad had a 1990 Ranger with the 4 cylinder, and it also had 8 spark plugs in it. It was great!

 

This system was referred to as a dual plug system...leading plugs, and trailing plugs..Although used mostly to reduce emissions, the extra set of plugs increased ignition dwell time--which increased power and increased mileage as well....

an increased dwell time and reduced, more controlled burn rate was some the benefits to the help increase efficentcy of the engine...