Omega Owners Forum
Chat Area => General Car Chat => Topic started by: Jimbob on 24 October 2011, 18:36:57
-
Was surprised to see an invoice for 8 spark plugs on my dads Jazz....
Quick check and yes, 2 plugs per cylinder 'to aid combustion, increase performance and reduce emissions'
Im skeptical, how does 2 plugs help?
-
It allows 2 flame fronts to be ignited inside the cylinder instead of just one, so the combustion is quicker and less ignition advance and, potentially, lower octane fuel can be used for a given performance.
.. And they can specify a silly service interval knowing that one of the plugs is bound to still be working... ::)
-
Not a new thing, either (and I don't know if Alfa were the first even): http://en.wikipedia.org/wiki/Alfa_Romeo_Twin_Spark_engine
-
Pretty much every aero engine has it. (but more for redundancy than performance). ;)
-
.. and if you switch off one of the mags on an aero engine (revert to a single spark), the RPM drops, so it is clearly slightly more efficient on twin sparks.
-
fair enough then, cheers :y
-
Pretty much every aero engine has it. (but more for redundancy than performance). ;)
Good point :)
I knew it had been around a long time - I saw a 1942 Jensen H type recently which had twin sparks on it's Inline 8 - but I didn't think they'd been around as long as 1914!
-
The 1928 Rolls Royce Phantom 2 prince of wales edition car we had as a wedding car had twin spark to......and it even adjusted the timing between the two sparks dependent on rpm to!
-
A 3 cylinder Smart Roadster has 6 spark plugs. 3 are easy to get at, the other 3 requires removal of the back of the car to gain access.
-
ISTR that Alfa had to do it to meet emissions standards :-\