Timing, Make You or Brake You 10/1/2006
In today’s world of sophisticated machines, electronic controls and management systems makes their operation possible. Back in the day of mechanical systems, points and condensers, many of the machines running today on the streets would not survive. Ignition points system can not control spark occurrence to support higher compression or cleaner burns. The points will not consistently deliver uninterrupted power. The point systems usually operate at a much lower voltage which means cooler flame fronts with lower yields of power.
There are devices to help point systems to become more efficient called signal boosters. The other issue with mechanical systems is the mechanical advance mechanism. This device holds engine timing to low degrees for start-up ability and slings out as engine speed increases to move point cam lobe forward to increase engine timing for run operation. This mechanism also can be altered to help with better engine control. Changing spring weight to slow the amount of advance engine timing for less spark knock can cause severe engine damage.
Spark knock is pre-detonation, piston rattle, and clatter in the engine that usually occurs at low engine speed trying to accelerate in too high of gear. This can also happen in high gear cruising speed. This destructive force is burning off too early as the piston is moving up sending the shockwave down against the piston causing it to clatter violently from front to rear and can even crack the piston. This shockwave can travel down the rod and flat spot crank bearings and in some cases distort rod journals out of round.
The use of different size limiter pins can change the overall amount of degree spread the unit will be capable of. All of these methods are proven to work but few are willing to pay for the time it takes to set it up and tune them.
Dynatek has a digital ignition and coil system that works very well. The Dynatek 2000 I-P system and its 3 ohm 40,000 volt coil pack will light the fire. This system is digital and programmable. The ability to program ignition timing makes this piece of equipment useful on a multitude of applications. The Dynatek 2000 I-P has the ability to use a vacuum operated electric switch linked to the intake manifold as a throttle position sensor. This unique feature will give multiple engine timing opportunities per throttle position and engine load. This means, if set correctly, no more spark knock. The digital age has allowed higher degree of tune ability making efficient cleaner operating equipment.
S&S has brought the digital control to a much higher level with the Intelligent Spark Technology ignition system. This system uses engine position, cam position, head temperature, intake manifold, and knock sensors to track, monitor and record and makes changes on the fly. This system is state of the art control for carbureted engines.
Electronic fuel injected (EFI) machines now have a lot of control. There are two systems in this group, open and close loop. Open loop has a predetermined program to control ignition and fuel delivery. Close loop is where O2 sensors are in the exhaust pipe measuring oxygen to effect changes as needed. There are systems running closed loop for 80% of the map and open loop for wide open throttle! The open/close system is not yet fully mature and really should be converted to open loop only with a 32 bit processor for better management. The processor I am using is a Power Commander and has 72 opportunities to make fuel and ignition changes to enhance fuel efficiency. Sometimes we get problems to solve that the customer has created by their product choices and we have to maximize their map to 144 grid opportunities to make even more changes.
The quest for efficiency has just escalated to a new level with the proposal of multiple fuel blends. This will test the resourcefulness of our physicist, scientist, electronic and mechanical engineers. The task at hand for tuners is how to marry this technology to a usable product the public will accept. As you can see with these developments engine timing will be even more closely controlled for engine efficiency and product reliability.
Good Riding and God Bless,
Steve Caldwell - steve@precisionvtwins.com
877.429.0399