8 plugs?

[8thTon]

Dual plugs are beneficial on engines with poor combustion chamber shape, which is most all 2 valve engines. With a 4 valve head and a centrally located plug they are not needed. It's all relative of course, as the unburned fuel didn't matter until they cleaned up the rest of the waste enough.

Yep, VW pirated the concept for the VR6 motor.

The VW VR6 was stolen from Lancia's narrow angle V4's. Then again Lancia innovated a huge number of things that are very common today.

 

[fastpakr]

The VW VR6 was stolen from Lancia's narrow angle V4's. Then again Lancia innovated a huge number of things that are very common today.

My comment was a continuation of 85's joke.

 

[RonD]

The 2.5 Lima has dual spark plugs as well. If I remember correctly, with that engine, the exhaust side was the primary is for ignition and the intake side was secondary is for emissions.

Yes, 2.5l Lima was dual plug
It was a stroked 2.3l Lima, different crank with longer connecting rods, but same engine otherwise

Both spark plugs fired at every TDC, no alternating and no reason for spark on exhaust stroke other than its easier to time and doesn't hurt anything to do it that way, not for emissions
Dual spark plugs do give better emissions, but nothing to do wth spark on exhaust stroke

On 1995 and later 2.3l/2.5l you can unplug either coil pack and engine will start and run OK, not as good as with both spark plugs firing, in fact this is a good test to see if a spark plug on that coil pack is bad, you would have a misfire that wouldn't be there if the other spark plug in that cylinder was working.

1994 and earlier 2.3l with separate ICM(ignition module) was a little different, only exhaust side coil pack was used for starting, intake side spark started when RPMs were above 400.

 

[19Walt93]

The second set of plugs was added to crutch the old head design so it would pass the newer emissions standards. We never had any trouble with them.
I've seen flatheads with dual plug heads, the factory plug sits way up by the valves so having a plug I over the piston should help I suppose.

 

[8thTon]

My '90 dual plug 2.3 was a great little engine. No it wasn't powerful but it was tractable and usable, and got quite good mileage for such a simple architecture. I'd gladly drive one again.

Interestingly I had a 91 S10 with a 2.5L 4cyl for a little while. It had a single point throttle body injector with probably a manifold pressure and temperature sensor, plus rpm and O2 sensors. It looked like maybe it had a 1bbl carb. It ran on a mapped fuel algorithm when not closed loop, and it ran OK I guess, but got crap mileage.

The Ford had dual plugs, MAFS, port injection, the works - a real engine management system. It worked too. I suspect it was because they got a lot of fleet sales and needed to make the economy numbers.

 

[sgtsandman]

Yes, 2.5l Lima was dual plug
It was a stroked 2.3l Lima, different crank with longer connecting rods, but same engine otherwise

Both spark plugs fired at every TDC, no alternating and no reason for spark on exhaust stroke other than its easier to time and doesn't hurt anything to do it that way, not for emissions
Dual spark plugs do give better emissions, but nothing to do wth spark on exhaust stroke

On 1995 and later 2.3l/2.5l you can unplug either coil pack and engine will start and run OK, not as good as with both spark plugs firing, in fact this is a good test to see if a spark plug on that coil pack is bad, you would have a misfire that wouldn't be there if the other spark plug in that cylinder was working.

1994 and earlier 2.3l with separate ICM(ignition module) was a little different, only exhaust side coil pack was used for starting, intake side spark started when RPMs were above 400.

Thanks for that. It's been 6 years since I had a '98 with the 2.5 and never had to mess with it much. Great engine for a big hunk of cast iron. Took for ever to warm up but that thing ran! I had bought it originally as a back up vehicle and something with the bed. After I got the 2011, I kept it for my daughter but she had zero interest in driving a stick. So I sold it to a buddy with a handyman business. He loves the thing and still has it to this day.

 

[falcon61]

94 2.4 dual spark 5mil odometer..I'm not walking or riding a bike

 

[rusty ol ranger]

The VW VR6 was stolen from Lancia's narrow angle V4's. Then again Lancia innovated a huge number of things that are very common today.

I wish these were still common today.... 702 CID of 12 cylinder american torque...brought to you by GMC....

 

[Dirtman]

Did you just google "worlds smokiest engine"?

 

[RonD]

109,000horse power, and diesel for best MPG

Might need a body lift, move rad support forward, and a bit of a hood scoop for clearance

https://o.aolcdn.com/images/dims3/GLOB/legacy_thumbnail/800x450/format/jpg/quality/85/http://www.blogcdn.com/www.autoblog.com/media/2011/07/largest-diesel-engine.jpg

And for sure bigger springs in the front

 

[rusty ol ranger]

Did you just google "worlds smokiest engine"?

If i died gagging on smoke from that id die happy.

I got a thing for big ass, old, gas engines from that general time period. I never heard of the V12 untill i was talkin to a guy at a tractor show who had his old GMC grain truck up there, it had the 438(?) V6 which isthe bigger V6 version of what they used for this V12.

 

[rusty ol ranger]

109,000horse power, and diesel for best MPG

Might need a body lift, move rad support forward, and a bit of a hood scoop for clearance

https://o.aolcdn.com/images/dims3/GLOB/legacy_thumbnail/800x450/format/jpg/quality/85/http://www.blogcdn.com/www.autoblog.com/media/2011/07/largest-diesel-engine.jpg

And for sure bigger springs in the front

WTF do they power with that thing?

 

[adsm08]

WTF do they power with that thing?

That is the starter for this:

 

[Dirtman]

Arlieigh burke's run gas turbines...

that thing is probably for a ferry, tanker or other massive slow ship.

 

[RonD]

LOL, Navy ships are mostly gas turbine or electric(nuclear or diesel generators)

The 109,000HP engine would be for a ship