Two spark plugs per cylinder...good or bad?
#11
#12
Thanks for the replies. To me this thread is very interesting.
Regarding the squish area and the turbulence it creates, does that mean the sparks should not fire until the piston at least gets to the squish area?
Regarding the 4 valves per cylinder, which came first the the 4 valve per cylinder design and then the 2 spark plugs or was the primary design for 2 spark plugs per cylinder and they needed 4 valves to make that work?
What is the reasoning behind 4 valves per cylinder? Does more air get sucked into the cylinder during the intake stroke because of it or is again, just to create turbulence?
Regarding the squish area and the turbulence it creates, does that mean the sparks should not fire until the piston at least gets to the squish area?
Regarding the 4 valves per cylinder, which came first the the 4 valve per cylinder design and then the 2 spark plugs or was the primary design for 2 spark plugs per cylinder and they needed 4 valves to make that work?
What is the reasoning behind 4 valves per cylinder? Does more air get sucked into the cylinder during the intake stroke because of it or is again, just to create turbulence?
Last edited by BobRR; 07-30-2018 at 07:40 AM.
#13
Thanks for the replies. To me this thread is very interesting.
Regarding the squish area and the turbulence it creates, does that mean the sparks should not fire until the piston at least gets to the squish area?
Regarding the 4 valves per cylinder, which came first the the 4 valve per cylinder design and then the 2 spark plugs or was the primary design for 2 spark plugs per cylinder and they needed 4 valves to make that work?
What is the reasoning behind 4 valves per cylinder? Does more air get sucked into the cylinder during the intake stroke because of it or is again, just to create turbulence?
Regarding the squish area and the turbulence it creates, does that mean the sparks should not fire until the piston at least gets to the squish area?
Regarding the 4 valves per cylinder, which came first the the 4 valve per cylinder design and then the 2 spark plugs or was the primary design for 2 spark plugs per cylinder and they needed 4 valves to make that work?
What is the reasoning behind 4 valves per cylinder? Does more air get sucked into the cylinder during the intake stroke because of it or is again, just to create turbulence?
4 valve engines have been around a long time, Ferrari even had a 5 valve engine. Its all about swirl in the cylinder. Getting a better burn on the gasses let in is where you get more power, less carbon monoxide, and a cleaner tailpipe, on a leaner mixture. Dual plugs have also been around a long time, mostly looking for more power, in the early days. Mercedes ran dual plugs from 2001 up to 2006, in all their 6 and 8 cylinder motors. While BMW doesn't run them at all. its all about that wheel now. Managing power, with a clean tailpipe, and getting mandatory fuel mileage. Notice all makers now are running turbos on almost all motors, and have decreased displacement, so they can have smaller cylinders to fill with gas, and still get the HP up. The gas most cars use today, driving at a cruise speed, wouldn't even let a 60's-70's motor even idle. Those motors would idle at anywhere between 3-6% CO, where todays motors, Idle at about .5-.75% before the cat. You can't even commit suicide by running the car in the garage anymore, you'll just get a bad headache by the time the car runs out of gas! And actually we don't even measure exhaust gases any more as a tech. We watch self adaptation, milliseconds of fuel injector opening and airflow lbs per second, going into the motor, and by that we decide on what the motor needs to be corrected. And all corrections are done in the ECU and techs have very little ability to adjust anything.
4 valves allow more air in and at more velocity, and will cause a better swirl
This is a very "readers digest" version of this subject!
Last edited by harleycharlie1992; 07-30-2018 at 09:19 AM.
#14
Regarding the 4 valves per cylinder, which came first the the 4 valve per cylinder design and then the 2 spark plugs or was the primary design for 2 spark plugs per cylinder and they needed 4 valves to make that work?
What is the reasoning behind 4 valves per cylinder? Does more air get sucked into the cylinder during the intake stroke because of it or is again, just to create turbulence?
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