Dual Spark Plugs

[raceman]

http://argent.fia.com/web/fia-public.ns ... 2-2010.pdf

U5.9U Electrical systems :
U5.9.1U Ignition is only permitted by means of a single ignition coil and single spark plug per cylinder. The use of plasma, laser or other high frequency ignition techniques is forbidden.
U5.9.2U Only conventional spark plugs that function by high tension electrical discharge across an exposed gap are permitted.
Spark plugs are not subject to the materials restrictions described in Articles U5.14 and 5.15U.

Double spark plugs are illegal!

darn, my bike has two spark plugs and the state-of-the-art F1 car can't have one..... pity, eh?

[autogyro]

Perhaps your bike would not run properly with one plug and the design is a compromise? Usualy to ensure a clean exhaust.

[alelanza]

Of all people I didn't expect Ron to chime in, though it's surprising we didn't hear more from him after seeing him in the practice sessions

Ron Dennis has cast doubts on Red Bull's claim that Sebastian Vettel suffered a spark-plug failure while leading the 2010 season opener in Bahrain last weekend. He eventually finished fourth after losing power in the later stages of the race.

Initially an exhaust problem was blamed but that was subsequently clarified by an official statement from the team.

But former McLaren boss Dennis was not convinced. "The lap times dropped so rapidly that one can imagine the electronic control unit (ECU) switching to a conservative programme to save fuel," he said.

"The problem with the Red Bull could be design. It could be the fuel tank is too small, or the fuel consumption is higher than they expected."
© ESPN EMEA Ltd.

http://en.espnf1.com/f1/motorsport/stor ... MP=OTC-RSS

[autogyro]

Nope Ron
All you have to do is look at Webbers times and his car and the small fuel tank idea is gone.
Considering McLaren make the ECU I do not think what Ron Dennis says is of much use when discusing the problem.
The "drop into lean configuration" suggestion could be a way of protecting a faulty ECU, which IMO is the only other cause of the problem if it was not a plug.

[raceman]

Perhaps your bike would not run properly with one plug and the design is a compromise? Usualy to ensure a clean exhaust.

nope, my bike will run properly with only one spark plug; but you are right about your last sentence; it is to ensure a clean exhaust and maximum ubilisation of fuel in the cumbustion chamber!

two spark plugs per cylinder = good power output + complete fuel burn

[iceracer]

I think there are significant advantage in dual plug performance!
as said early in tread old pkw alfa 164 has dual plugs and later Alfa 156!..
i remebrer late in 1980 something ,Alfa/fiat group made a commercial thing about the benefit of dual plugs!
they put Swedish/ World Rally star Björn Waldegård, or was it Stig blomquist to drive the Alfa 164 DP from stockholm to Milano with on a fuelsaving trip!
remeber Alfa 164 is a BIG car !..
result of milage was 0.39L/10km !,,, very, very good campare to those days for ex volvo 740 (b230) engines that could not run better then 0,9L /10Km

AND COUNTERWISE YOU SHOULD HAVE SIGNIFICANT hp GAIN ON SAME AMOUNT OF FUEL WHEN USING dp ENGINES!.._AND THAT SHOULD HAVE BEEN ON THE F1 CARS ,, FOR PERFORMANCE REASON!..I CANT really FIGURE OUT WHY DUAL PLUGS ARE NOT ALOWED!..

But i guess if development of this kind of engine did go right, mileage should have dropped! way below 0.3L/10Km 20 years later AND THAT DONT LIKE FUEL/GAS COMPANYS AROUND THE WORLD!,,and thats the real reason we dont have this kind of engines on every car..

[mep]

A colleague told me that you can put two plugs in a series connection to save one inductor for two cylinders that are fired on the same time. So you have one wire to the first plug then the cylinder head is used to connect to the next plug and a wire bag to the generator. But by this the current flows in one spark in opposite direction than in the other. So in one plug the spark will go from the centre electrode to the side electrode and in the other from the side to the centre. Due to whatever reason the spark plugs don’t like this so one plug has a drastically reduced millage. As they have 8 cylinder engines in F1 I can imagine they do that to reduce the amount of coils and therefore have to handle the problem.
I hope you could follow this description.
What do you think?

Edit: Notice I was basicly not speaking about 2 plugs in one cylinder but about 2 cylinders firing at the same time with one coil.

[autogyro]

I think dual plugs are very difficult to justify.
There are many variables not least the size and shape of the combustion chamber.
In an F1 engine there is little if any area left to place an extra plug anyway.

[WhiteBlue]

I think they would probably rather use laser ignition instead of spark plugs if the rules are liberated.

[Formula None]

I think dual plugs are very difficult to justify.
There are many variables not least the size and shape of the combustion chamber.
In an F1 engine there is little if any area left to place an extra plug anyway.

What's the main limitation with a spark plug's OD? Can they not be made significantly thinner?

[Giblet]

Insulation.

While riding my 80cc 2 stroke mountain bike, the plug wire came lose, so reached down and pushed it back on.

The burn on my hand was enough incentive to remember to stop if it ever happened again.

[Formula None]

Found this on another forum. F1 plug on the left (for reference, a US quarter is 24.26 mm (0.955 in) in Dia, so looks like maybe an M10 thread):



From the NGK website:

This spark plug has a smaller heat exposed isolator surface exposed and is a super- old spark plug; therefore, it gets dirtyy easily. To overcome dirty, a capacitor discharge system is used which reaches rapidly the required voltage to produce the sparks.
It is used in engines of high performance like the engines of Formula 1.

Some more F1 plugs:



This guy is attempting to make plugs with an M2.5 thread for his 1/4 scale F1 model (M3 thread version shown below):

http://www.f1-2000.co.uk/index.php?f=ignition_system

[Caito]

A colleague told me that you can put two plugs in a series connection to save one inductor for two cylinders that are fired on the same time...

It's used in many of current production engines, it's called the wasted spark.
http://en.wikipedia.org/wiki/Wasted_spark

The cylinder in compression offers much more resistance, so there's a bigger voltage drop in the cylinder which is in compression. The wasted spark in the other(exhausting) cylinder reduces emissions.

[aleks_ader]

That pic...



is there on that article of visit of Champion factory and F1 facility departmend...

http://www.caranddriver.com/columns/tec ... -in-toledo

Nice article from december 2005 descriptions of sparkplugs from year 2000 (Ferrari F2000)...


Dimentions at that time:

Dia: 7.7 mm
Long: 38 mm
Mass 10.7g

"Since we came out with that plug in 1999, they haven't asked us for any more weight reductions"

[olefud]

I think there are significant advantage in dual plug performance!
as said early in tread old pkw alfa 164 has dual plugs and later Alfa 156!..
i remebrer late in 1980 something ,Alfa/fiat group made a commercial thing about the benefit of dual plugs!
they put Swedish/ World Rally star Björn Waldegård, or was it Stig blomquist to drive the Alfa 164 DP from stockholm to Milano with on a fuelsaving trip!
remeber Alfa 164 is a BIG car !..
result of milage was 0.39L/10km !,,, very, very good campare to those days for ex volvo 740 (b230) engines that could not run better then 0,9L /10Km

AND COUNTERWISE YOU SHOULD HAVE SIGNIFICANT hp GAIN ON SAME AMOUNT OF FUEL WHEN USING dp ENGINES!.._AND THAT SHOULD HAVE BEEN ON THE F1 CARS ,, FOR PERFORMANCE REASON!..I CANT really FIGURE OUT WHY DUAL PLUGS ARE NOT ALOWED!..

But i guess if development of this kind of engine did go right, mileage should have dropped! way below 0.3L/10Km 20 years later AND THAT DONT LIKE FUEL/GAS COMPANYS AROUND THE WORLD!,,and thats the real reason we dont have this kind of engines on every car..

Duel plugs, other than avoiding failure through redundancy, are at best a band aid. A proper head/piston design greatly enhances flame travel through squish, swirl and tumble. These convection mechanisms augment flame travel by double digit factors.

Alfa is a poor source for supporting duel ignition. They were wedded to the hemi combustion chamber which has poor squish and intake charge characteristics. Similarly, hemi combustion chambers were common in aircraft engines, though they needed redundant ignition by regulation.