Alec87CJ\'s Ignition Questions...
*Alec87CJ* Asked,
*I have a friend who just picked up a J truck with a 401 in it. It has points in it! What would be the easiest distributor to swap in, in order to have an electronic ignition?*
Depends what year the engine is. If the distributor drive gear, and lower distributor housing match the early Motorcraft distributors, (say, '79 Jeep anything with 304 or 360 CID AMC engine), and the oil pump drive are the same, then the entire upgrade is off the shelf. If you want to keep the factory quick connects, it will take some extra time to make the wiring harness, but it only adds about $30 to the cost of the project, and you can take any faulty components out and just snap new ones back in.
(See the thread you orignally posted your questions in for all of the parts needed an some pricing.)
*Alec87CJ* Asked,
*Also, I put the HEI in my 258. It already had an electronic ignition, but after hearing about how much everyone I loved theirs, I switched mine over too. I thought it was just me but the only "increase" in performance I saw was easier starting in the morning.*
*Should I just switch back and off load my HEI setup on someone else?*
What electronic ignition? Jeep went dumpster diving sometimes, and the systems they came up with didn't always do the deed, if you know what I mean...
If you had the Motorcraft distributor, all you needed was a cap and rotor upgrade, maybe a premium coil, plug wires and a set of advance springs. Around $80, total.
I'm not real familiar with that year of six banger, so I could be wrong...
I wouldn't call it 'unloading it', it's a great improvment for someone with points! I bet you could make them a heck of a deal on it if you decide to go back to what you had before...
*Alec87CJ* Asked,
*One more thing...there was mention of the HEI grouding out... would this explain why I see half a dozen burned up rotors a week?*
*(Not in my setup...just at work off of other people's GM's.)*
Of corse not YOUR jeep.... (Go look for black carbon & 'pencil' tracks on the rotor top, and red dust under the rotor, and get back to me...)
There are three things that almost all armatures do that should be taken care of...
1. Put the distributor drive gear on backwards. The chevy distributor has an odd number of teeth, so there is a front and a back to the gear. There is a dimple in the gear just below the gear teeth, and just above and offset to the roll pin hole. That dimple should line up with the rotor nose. If it doesn't, even when your engine is firing at the correct time, the rotor is 42 crank degrees away from the plug tower it's supposed to be firing.
That spark has to go somewhere, and with a cap full of ozone, and the distributor shaft closer than the plug terminal, it's either going to fire the plug tower it's closest to (detonation), or two plug towers (detonation), or to the distributor shaft (dead miss).
Combine that rotor phasing screw up with centrifugal advance movement of the rotor, and vacuum advance, and trigger errors, and cheap parts, and tolerances up to 20 times what they should be and it's a recipe for burned parts, and even engines hammered to death.
The AMC gears have an even number of teeth, (The gears used on the I-6 upgrades are AMC) so the most they will be mis-aligned is about 6 crank degrees.
(And nobody seems to know this stuff...)
2. Use those poor quality caps and rotors. Aluminum is a poor conductor of electricity compared to good brass terminals. The spark energy is going to take the path of least resistance, and to an aluminum plug terminal is not attractive to the spark.
Rotors are my pet peeve outside of aluminum terminals.
GM HEI rotors are notorious for being thin and easy for electrical charges to blow through. Aftermarket replacements form Mexico (or god knows where) are even less trustworthy. The spark energy is supposed to come down the center electrode, and if everything goes correctly, follow the rotor arm out to the plug terminals. It does just that a fare amount of the time.
It also finds the ozone, and the carbon particles in the rotor well, (rotor well, the hole the center spring fits into) and finds an easier path to go, just straight through to the distributor shaft and counter weights.
Ever see red dust inside those rotors? That's steel that has been VERY hot at one time.
The spark energy incinerates the iron in the steel, while trying to weld the weights and advance head to the distributor shaft.
(Anyone ever seen the red coating on a blast furnace? That is how hot the spark energy is.)
3. Not adjusting the rotor nose.
Most GM Style HEI rotors are generic at best. My favorite saying is 'One size fits nothing'. Those discount rotors are made to work with variations in distributor shafts, wear in distributor shafts, at least 50 different manufacturers of distributor caps, all slightly different, and no common quality control.
The good news is that the nose of most aftermarket GM HEI rotors can be bent our slightly to make them fit the cap. Just get a hold of it with a pair of needle nose pliers and bend it out a little, and put the cap on and turn the distributor gear. If it clears, bend it out a little more until it contacts one or more of the towers, then back it off until it just clears the inside of the towers.
(If you want to keep an old HEI around just to do this with, it makes a good tuning tool.)
That closes up the air gap between the rotor and the cap towers. I have seen gaps of 1/4" when the max. spec. is 0.015".
Just drop the box on end once, and the adjustment is shot, if it ever had one to begin with.
Does that answer your questions?
(You owe me one CJ Dave...)
When a fool and a wise man argue, Onlookers can't tell the difference...
*Alec87CJ* Asked,
*I have a friend who just picked up a J truck with a 401 in it. It has points in it! What would be the easiest distributor to swap in, in order to have an electronic ignition?*
Depends what year the engine is. If the distributor drive gear, and lower distributor housing match the early Motorcraft distributors, (say, '79 Jeep anything with 304 or 360 CID AMC engine), and the oil pump drive are the same, then the entire upgrade is off the shelf. If you want to keep the factory quick connects, it will take some extra time to make the wiring harness, but it only adds about $30 to the cost of the project, and you can take any faulty components out and just snap new ones back in.
(See the thread you orignally posted your questions in for all of the parts needed an some pricing.)
*Alec87CJ* Asked,
*Also, I put the HEI in my 258. It already had an electronic ignition, but after hearing about how much everyone I loved theirs, I switched mine over too. I thought it was just me but the only "increase" in performance I saw was easier starting in the morning.*
*Should I just switch back and off load my HEI setup on someone else?*
What electronic ignition? Jeep went dumpster diving sometimes, and the systems they came up with didn't always do the deed, if you know what I mean...
If you had the Motorcraft distributor, all you needed was a cap and rotor upgrade, maybe a premium coil, plug wires and a set of advance springs. Around $80, total.
I'm not real familiar with that year of six banger, so I could be wrong...
I wouldn't call it 'unloading it', it's a great improvment for someone with points! I bet you could make them a heck of a deal on it if you decide to go back to what you had before...
*Alec87CJ* Asked,
*One more thing...there was mention of the HEI grouding out... would this explain why I see half a dozen burned up rotors a week?*
*(Not in my setup...just at work off of other people's GM's.)*
Of corse not YOUR jeep.... (Go look for black carbon & 'pencil' tracks on the rotor top, and red dust under the rotor, and get back to me...)
There are three things that almost all armatures do that should be taken care of...
1. Put the distributor drive gear on backwards. The chevy distributor has an odd number of teeth, so there is a front and a back to the gear. There is a dimple in the gear just below the gear teeth, and just above and offset to the roll pin hole. That dimple should line up with the rotor nose. If it doesn't, even when your engine is firing at the correct time, the rotor is 42 crank degrees away from the plug tower it's supposed to be firing.
That spark has to go somewhere, and with a cap full of ozone, and the distributor shaft closer than the plug terminal, it's either going to fire the plug tower it's closest to (detonation), or two plug towers (detonation), or to the distributor shaft (dead miss).
Combine that rotor phasing screw up with centrifugal advance movement of the rotor, and vacuum advance, and trigger errors, and cheap parts, and tolerances up to 20 times what they should be and it's a recipe for burned parts, and even engines hammered to death.
The AMC gears have an even number of teeth, (The gears used on the I-6 upgrades are AMC) so the most they will be mis-aligned is about 6 crank degrees.
(And nobody seems to know this stuff...)
2. Use those poor quality caps and rotors. Aluminum is a poor conductor of electricity compared to good brass terminals. The spark energy is going to take the path of least resistance, and to an aluminum plug terminal is not attractive to the spark.
Rotors are my pet peeve outside of aluminum terminals.
GM HEI rotors are notorious for being thin and easy for electrical charges to blow through. Aftermarket replacements form Mexico (or god knows where) are even less trustworthy. The spark energy is supposed to come down the center electrode, and if everything goes correctly, follow the rotor arm out to the plug terminals. It does just that a fare amount of the time.
It also finds the ozone, and the carbon particles in the rotor well, (rotor well, the hole the center spring fits into) and finds an easier path to go, just straight through to the distributor shaft and counter weights.
Ever see red dust inside those rotors? That's steel that has been VERY hot at one time.
The spark energy incinerates the iron in the steel, while trying to weld the weights and advance head to the distributor shaft.
(Anyone ever seen the red coating on a blast furnace? That is how hot the spark energy is.)
3. Not adjusting the rotor nose.
Most GM Style HEI rotors are generic at best. My favorite saying is 'One size fits nothing'. Those discount rotors are made to work with variations in distributor shafts, wear in distributor shafts, at least 50 different manufacturers of distributor caps, all slightly different, and no common quality control.
The good news is that the nose of most aftermarket GM HEI rotors can be bent our slightly to make them fit the cap. Just get a hold of it with a pair of needle nose pliers and bend it out a little, and put the cap on and turn the distributor gear. If it clears, bend it out a little more until it contacts one or more of the towers, then back it off until it just clears the inside of the towers.
(If you want to keep an old HEI around just to do this with, it makes a good tuning tool.)
That closes up the air gap between the rotor and the cap towers. I have seen gaps of 1/4" when the max. spec. is 0.015".
Just drop the box on end once, and the adjustment is shot, if it ever had one to begin with.
Does that answer your questions?
(You owe me one CJ Dave...)
When a fool and a wise man argue, Onlookers can't tell the difference...
