4cyl/8 spark plugs

[ati190]

hello all

I'm not sure if I'm posting this in the correct section, if not can a mod please move it? Ok for my question. I had an 89 Ford Ranger (first truck at 16), and it baffled me by having 8 spark plugs. What were the reasons for the double plug block? Isn't it the same concept as having double leads on a spark plug without actually having 8 spark plugs or am I wrong? From my understanding, the design wasn't to increase power, but to reduce emissions? Which is what is believed to happen when you add leads on a spark plug..

ati190

 

[Mark_88]

Hmmm...I thought there was also a slight delay in their firing so that it would help burn off excess gas...can't remember where I read that...but probably on a discussion here...

 

[Bryan22]

kind of a different question on the same subject, which side fires when cranking?

 

[shadetree]

Ok, for the umpteenth time. Ford went to dis, and edis with dual plugs for one reason, emissions. With two plugs the fuel mixture is ignited with two flame fronts. This gives a more complete burn of the fuel mixture thus reducing emissions. It also gives a slight increase in power and fuel mileage, tho hard to detect.

4 plugs fire at the same time. Two at the end of the compression stroke of one cylinder, and two on the exhaust stroke of another cylinder. The plugs firing on the exhaust stroke is called "waste spark" as it has no purpose other than allowing a path to complete the firing circuit. Some think it is to burn remaining unburned gases from combustion, but that is not the case. Any remaining fuel has no oxygen for ignition, plus the waste spark doesn't see enough resistance to generate a high voltage.

The drivers side plugs do not fire during engine start. There is a "spark inhibit" circuit to control this. This is done to provide more electrical energy during startup. This sometimes makes for a pain in the ass diagnostic as the engine will still run fine with only one bank of plugs firing. And, if there is a problem with the passenger side not firing,the truck won't start as the drivers side is inhibited.

This is not a new process. This design is found on many other vehicles of different mfgr.shady

 

[Mutant Pony]

My '73 Artic cat, El 'tigre (Kawasaki) has dual plugs. It is a 2cyl with 4 plugs. As Shady said: "it is not new". It is the first and only (that I know of) american engine to use them.

 

[Touring23]

Hi guys. New (old) guy here, just stopping by. Here are some other dual-plug engines:
Nissan Z20 series in the 200sx & 720 pickup
Nissan Z18ET & CA20E
Toyota 3T&4T-GTE won the WRC Group B
Porsche 911
Porsche 356
Ferrari 275GTB Daytona
Ferrari 500
Honda's recent i-DSL (staggered spark)
Dodge New Hemi
Mercedes 3-valve V8 M112, ie. SL500
Maserati A6G54
Maserati 3500GT
Alfa Romeo 75 & 105
Aston Martin DB4 GT
Lycomings in airplanes, for example the O-200, -240, & -320
Rotax (BMW f650 motorcycle)
Classic VW (mod)
Ducati 2-valvers
Harley (mod)
Moto Guzzi 900/1000ss
2006 Kawasaki Vulcan 1600
Suzuki Marine 225HP 2.7L V6 outboard
Mercury Marine
Ford Flathead (mod)

Dual plugs are where it's at, Baby!
(Happy New Year everyone)

 

[Mutant Pony]

Oh, they have been using them in top fuel dragsters for quite a few years now too.

 

[Touring23]

Yup, all though they're burning some pretty exotic stuff.

 

[shadetree]

Ford Flathead (mod)
Dual plugs are where it's at, Baby!
(Happy New Year everyone)

Haven't heard of this one. Mod by whom??????????shady

 

[Touring23]

This is all I have on flatheads: http://www.angelfire.com/co/flatheads/cylhead.html
Unfortunately, it seems the flatheadsforever site has retired or moved.

*edit* A quick Google search turned up:
http://www.flatfire.com/flatfire2.htm
http://www.flatfire.com/enginedev.htm
http://www.flatheadpower.com/tech/viewtopic.php?f=5&t=7523

Seems to be a small bit of info out there...?

 

[feellnfroggy]

kind of a different question on the same subject, which side fires when cranking?

Both sides fire on cranking, but the drivers side is the primary spark. The pass side is the waste spark. Like someone said slight delay to burn off excess exhaust gasses. Right thought stupid idea. On Ford's behalf I mean.

 

[shadetree]

Both sides fire on cranking, but the drivers side is the primary spark. The pass side is the waste spark. Like someone said slight delay to burn off excess exhaust gasses. Right thought stupid idea. On Ford's behalf I mean.

You don't have a clue as to what you are talking about.shady

 

[Bryan22]

now im confused, i thought only one side fired while cranking.... passenger side? or both?

 

[Bryan22]

The drivers side plugs do not fire during engine start. There is a "spark inhibit" circuit to control this. This is done to provide more electrical energy during startup. This sometimes makes for a pain in the ass diagnostic as the engine will still run fine with only one bank of plugs firing.
shady

there it is!

 

[feellnfroggy]

You don't have a clue as to what you are talking about.shady

Who the hell are you? Ive been working on my ignition for the last three months. I had 2 dead points in the waste spark coil of my 92 2.3l. I've swapped wires swapped coils run plugs checks on each of them at least a hundred times. I get fire from all points whether starting running in open cycle or after the engine in warmed up. My primary spark is my driver side plugs. And dont be so Fuggin rude with your reponses. A simple I think you might be mistaken would have worked just fine.

Edit:: I just saw the post about the spark inhibit. I have never experienced this before. However my dual spark 2.3 mustang ('93) and this ranger I have now('92) were both over 100k by alot, Its possible my system has a problem.