How Do I Put LS-1 Ignition on Lt-1
06-15-2003, 09:00 AM
#16
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Join Date: Dec 1999
Location: Upstate New York,USA
Posts: 1,791
Yes, the optical portion of the Optispark is still needed since it has the important job of not only knowing;
1. Crank position
2. Which cylinder is due a spark command
3. When to fire the spark
But also tells the PCM what fuel injector needs to be fired, when it's to be fired and for how long (Injector pulsewidth) and provide a tachometer signal.
The only Electronic part of the Optispark that is disabled by the installation of the LTCC setup is the high voltage cap and rotor. The high voltage portion of the Optispark is the part that has caused MOST failures of these stock units. There are other issues that have caused optispark failures. Loose, poorly assembled rotors(most commonly reported by people that have replaced the stocker and having subsequent failure from the replacement unit).
Bad bearings has occasionally been reported as a source of failure too. By and large though, the high voltage cap and rotor have been the dominant reason for failure. All distributors of this cap/rotor design degrade over time due to the denegration of the tip of the rotor and the caps plug wire posts where the high voltage spark leaps from rotor to the posts. These metal components have a finite life and are meant to be replaced on a periodic basis. That's the way it's always been. Just because GM deemed to lay the distributor horizontally instead of vertically doesn't change this fact. It wears out. Saying the whole Optispark is crap just because it doesn't last forever is shortsighted. It's a better conventional style of distributor than anything before its design. It just happens to carry a legacy that all distributors of that design must shoulder. An expendable part.
The optical portion is fantastic. Basically an 'eye' and a light source. Like when you watch a TV show thru the blades of a running fan. Only a computer is counting how many times the fan blades pass in front of your eyes.
The Light - A bright Light Emitting Diode
The Eye - A photo transistor(changes voltages/pulses when the light it sees changes from light to dark and back)
The Fan - A thin metal disk having 360 (ie: 360 degrees of a circle) small slots around it's outter perimeter. Also has 4 slightly larger slots at 90 degrees apart to tell the PCM when a cylinder/injector is to be fired/injected
The disk is driven by the camshaft and spins in a small airspace between the LED and the Eye/phototransistor. The PCM counts the outter ring pulses to keep track of where the crank is in it's revolution and knows from the 90 degree spaced slots when and what cylinder/injector to service.
1. Crank position
2. Which cylinder is due a spark command
3. When to fire the spark
But also tells the PCM what fuel injector needs to be fired, when it's to be fired and for how long (Injector pulsewidth) and provide a tachometer signal.
The only Electronic part of the Optispark that is disabled by the installation of the LTCC setup is the high voltage cap and rotor. The high voltage portion of the Optispark is the part that has caused MOST failures of these stock units. There are other issues that have caused optispark failures. Loose, poorly assembled rotors(most commonly reported by people that have replaced the stocker and having subsequent failure from the replacement unit).
Bad bearings has occasionally been reported as a source of failure too. By and large though, the high voltage cap and rotor have been the dominant reason for failure. All distributors of this cap/rotor design degrade over time due to the denegration of the tip of the rotor and the caps plug wire posts where the high voltage spark leaps from rotor to the posts. These metal components have a finite life and are meant to be replaced on a periodic basis. That's the way it's always been. Just because GM deemed to lay the distributor horizontally instead of vertically doesn't change this fact. It wears out. Saying the whole Optispark is crap just because it doesn't last forever is shortsighted. It's a better conventional style of distributor than anything before its design. It just happens to carry a legacy that all distributors of that design must shoulder. An expendable part.
The optical portion is fantastic. Basically an 'eye' and a light source. Like when you watch a TV show thru the blades of a running fan. Only a computer is counting how many times the fan blades pass in front of your eyes.
The Light - A bright Light Emitting Diode
The Eye - A photo transistor(changes voltages/pulses when the light it sees changes from light to dark and back)
The Fan - A thin metal disk having 360 (ie: 360 degrees of a circle) small slots around it's outter perimeter. Also has 4 slightly larger slots at 90 degrees apart to tell the PCM when a cylinder/injector is to be fired/injected
The disk is driven by the camshaft and spins in a small airspace between the LED and the Eye/phototransistor. The PCM counts the outter ring pulses to keep track of where the crank is in it's revolution and knows from the 90 degree spaced slots when and what cylinder/injector to service.
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