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4 Cylinder ranger

My friend’s ranger has four cylinders and eight (8) spark plugs. I’ve never seen this before. What’s the purpose of the “extra” plugs. And, wouldn’t this thing be a problem to set the timing??

To burn gas completly.
Cars,trucks,motorcycles,snowmobiles have been doing this for years

My Honda V-twin motorcycle has two plugs per cylinder. The point is to have two ignition points to more completely burn the fuel. Timing isn’t an issue because both plugs within the same cylinder fire at the same time. I believe many engine designs could benefit from having two plugs per cylinder, but because of the shape of the engine, it isn’t practical.

Dual plugs allow the dealership to charge you twice as much for a tune-up.


The purpose of 2 plugs per cylinder is to help completely burn all the fuel mixture, but I never could figure how you could ignite a fire that was already burning. Maybe the fire at the same time but I once had a car that the 2nd plug fired about 10 degrees after the first. Never made sense to me.

IMO, the extra plugs are a substitute for a poorly designed motor trying to keep up with modern expectations…maybe the case with Ranger still using up the Pinto based 4 cyls for years after their demise.

No one ever “accused” the Ranger of cutting edge technology that I can recall.

I remember back in the early 1960’s seeing a fire engine that had two spark plugs per cylinder. The engine had 6 cylinders, but probably had a large displacement. I suppose that the dual spark plugs insured complete combustion–very important when the engine is under load running the pump–and also provides a back-up if a plug fails.

There are lots of V-twin motorcycles with two plugs per cylinder, including several current models from Honda. Would you call them “poorly designed motors?”

Are you putting the Ranger 4 cyl engineering in the same league as a Honda motorcyle ? I should have said “the extra plugs in this situation IMO” and if Honda supplied V twins to Ranger for their motors, I WOULD expect 2 plugs per cyl.
Poor designed does NOT mean poor engineering. Engineers use techniques to extend existing motor lines to save $$$$ and short term profit over long term function. The Ranger is a perfect example of this “engineering” mentality as extending competitive life of the Pinto based motor was their goal…not maximizing performance and longevity as Honda did with motorcycles. Besides, the higher RPM of Cycle engines present different ignition problems then a Ranger PU. Not a valid comparison IMO. Look at the number of superior 4 cyl motors in other w/o two plugs per cylinder that out perform a Ranger. It’s always a $$$$$ decision.

I just thought I would ask. Thanks for clarifying.

I remember back in the 60s when fire trucks had 2 plugs per cylinder. I thot they had a backup ignition system, is case one failed.

“Timing isn’t an issue because both plugs within the same cylinder fire at the same time.”

Hey, Whitey old buddy, you are probably more up to date about 2 plugs per cylinder than I am but the only car I ever had with 2 per cylinder fired one 10 degrees after the other. BUT that was several years ago.