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TR6 Electronic iginition for TR6
- Thread starter ichthos
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Kevin,
I strongly advise you to stick with stock ignition on your car until you are completely familiar with it's workings and can keep it on the road with ease. There are so many little nuances associated with the ignition on the TR6 and it's ability to run properly that you will lose some of this by converting. You can run the car with a variety of settings with the stock ignition and change it's character ever so slightly with each adjustment. Bottom line, it is pretty hard to screw up the car's basic performance once all things electrical are understood and set properly. I say dance with whom you brung until you learn how to waltz. Electronic ignition, IMHO, is fine if all else is done to make your car run perfectly and you have complete working knowledge of why it does so. It will not make your car run better or make an engine that has some mechanical needs improve. One small point about electronic ignition that many overlook is you cannot simply leave the ignition key on in the run position while fiddling with the car without cooking the expensive module in about 3 minutes. Spend that hundred bucks or so on some more needed part and enjoy the car the way it was meant to be. That said, electronic ignition is easy to install, easy to screw up and will not change gas mileage. Stay original and enjoy the ride.
Now, many here on the forum have run electronic ignition and swear by it. From the Pertronix and Crane all the way up the ladder to complete distributor transplants and super sophisticated modules. I have no problem with that. New points and condensor are about 6 bucks and fit nicely in the back of your cubby and install with a small screwdrive and can be set with a beer can pop top.
Bill
I strongly advise you to stick with stock ignition on your car until you are completely familiar with it's workings and can keep it on the road with ease. There are so many little nuances associated with the ignition on the TR6 and it's ability to run properly that you will lose some of this by converting. You can run the car with a variety of settings with the stock ignition and change it's character ever so slightly with each adjustment. Bottom line, it is pretty hard to screw up the car's basic performance once all things electrical are understood and set properly. I say dance with whom you brung until you learn how to waltz. Electronic ignition, IMHO, is fine if all else is done to make your car run perfectly and you have complete working knowledge of why it does so. It will not make your car run better or make an engine that has some mechanical needs improve. One small point about electronic ignition that many overlook is you cannot simply leave the ignition key on in the run position while fiddling with the car without cooking the expensive module in about 3 minutes. Spend that hundred bucks or so on some more needed part and enjoy the car the way it was meant to be. That said, electronic ignition is easy to install, easy to screw up and will not change gas mileage. Stay original and enjoy the ride.
Now, many here on the forum have run electronic ignition and swear by it. From the Pertronix and Crane all the way up the ladder to complete distributor transplants and super sophisticated modules. I have no problem with that. New points and condensor are about 6 bucks and fit nicely in the back of your cubby and install with a small screwdrive and can be set with a beer can pop top.
Bill
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DougF
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I purchased Pertronix a while back and love it. I probably won't put it on my other two cars, but for reasons unrelated to performance.
It took minutes to install. When installing, you must pay attention to your wires. I saw one installation last a minute because a wire was rubbing the distributor shaft. Cross wiring will also kill the unit. These two things are simple to avoid.
As Bill said, if you have other problems electronic ignition won't fix them. I understand his viewpoint of waiting until the car is sorted out, but the other side is that it will eliminate one more area for fixing.
Should you decide to switch over, keep your current ignition in the glove box for emergency purposes.
It took minutes to install. When installing, you must pay attention to your wires. I saw one installation last a minute because a wire was rubbing the distributor shaft. Cross wiring will also kill the unit. These two things are simple to avoid.
As Bill said, if you have other problems electronic ignition won't fix them. I understand his viewpoint of waiting until the car is sorted out, but the other side is that it will eliminate one more area for fixing.
Should you decide to switch over, keep your current ignition in the glove box for emergency purposes.
Alan_Myers
Luke Skywalker
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Hi Kevin,
First, let's narrow down what you mean by "electronic ignition". Maybe it's just me, but there seem to be a number of components that fall under that rather broad heading, and it might be written or said to mean one thing, but interpreted as another.
Many vendors offer electronic modules to replace the mechanical contact points inside a dizzy, and refer to these as "an electronic ignition". I suspect this is what you are asking about.
These modules seem to all use either magnets or LEDs with light sensors to time the firing of the ignition. But, even though the mechanical contact points are eliminated, the basic distributor function essentially remains the same.
IMHO this is really only the first small step toward an electronic ignition and Bill is quite correct: There is limited value to the relatively minor change. It might make for slightly easier starting in some circumstances and perhaps a little smoother running, but mostly just eliminates having to fiddle with point adjusments and replace a worn set occasionally. I doubt you'll see very much change in gas mileage. And, on the downside, electronic trigger modules can be a lot more sensitive to incorrect voltage or electrical system spikes. Changing to a well-matched coil might be a good idea at the same time the module is installed. (I suspect some or most premature module failures may happen when they're used with a high output "sport" coil. But this is just a guess based on very limited observation. Nothing scientific about it.)
When points get old and start wearing, the car will gradually run poorer, but typically giving you a bit of warning. With electronic ignition modules the car sometimes either runs... or not, nothing in between and little or no warning given. It seems to me an awful lot of folks who have made the change to an electronic module continue to carry a good old point set around in the glove box.... "just in case".
Next up is the distributor itself. The original Lucas are actually pretty good, but there might be some good reasons for changing: It's badly worn, other modifications to the car require a change, etc.
AFAIK, there is now only one manufacturer of replacement dizzies that will easily fit TR6: Mallory offers a Unilite model that will work and is fully electronic. There's a choice of this model: With or without vacuum advance (mechanical/centrifugal advance only).
One issue with the Mallory replacement in a TR6 specifically is that this dizzy has no tachometer drive gear (like the original Lucas dizzy does). So, installing the Mallory also means changing to an electronic tachometer (either install a replacement like a 5" indash AutoMeter or Stewart Warner, or have the stock tach converted to electronic innards for a stock look).
So, having the original Lucas dizzy rebuilt can be pretty attractive in some respects, whether sticking with points or installing some sort of electronic module inside it.
The choice of vacuum advance or non-vacuum advance is an important one, too. Non-vacuum advance is primarily for racing, such as when certain performance carbs require doing away with any vac advance.
Vacuum advance is more of a street car design, offering a bit smoother running in low- to mid-range rpm, with another key purpose of helping conserve fuel. The original Lucas dizzies all have vacuum advance (actually, with some TR6 I think it's both vacuum advance and vacuum retard, or vacuum retard only. But, generally speaking... the idea is still the same... use engine vacuum to adjust ignition timing). It's possible to convert a Lucas from vac advance to non-vac advance - i.e., to strictly mechanical/centrifugal advance - if that's wanted for some reason. However, that's not something I'd recommend to anyone seeking a street-mannered car and better fuel mileage.
Back in the good old days, an upgrade to a higher output "sport" coil with maybe 20 or 30% higher voltage and a re-curved/modified stock distributor, or possibly a Dual-Point Mallory dizzy (two sets of points to carry higher voltage than a single set), were about the extent of our choices. In some case, such as certain vintage competition classes, we still might be limited to this sort of setup.
Next step up the evolutionary ladder today is a capacitive discharge (CD) box, which ain't just for racin'. This is an additional piece of equipment and is where some real performance improvements from an electronic ignition system begin to be noticible. CD boxes often not only put out substantially stronger spark voltage, some also have "multi-spark" modes, at least up to 3000 rpm or so. These fire the plug in a cylinder several times during each combustion stroke. This makes for a more complete burn of all the fuel in the cylinder, which in turn means more horsepower and so either less fuel is used to achieve the same power output, or more power is gotten with the same fuel quantity... however you want to look at it.
In most cases, the voltage supplied to the plugs by a CD box is much higher too... ISTR about 40X increase (read that as fourty *times*, not 40%!) in the case of a stock TR4 vs. a Mallory 6AL box (probably similar with TR6 and other brands/models of CD boxes).
The much higher voltage can be used safely because the CD box sends it to the plugs, not through the dizzy where the voltage would quickly burn up points or delicate electronics. Since the dizzy is now acting only to carry and send a smaller trigger voltage, either points or the electronic triggering module can be expected to last a long time. They are protected from higher voltage wear and tear. Even standard points will often last 10X longer, but by this level of modification it just makes sense to convert to full electronic triggering, too. (Mechanical points will typically have a much lower max rpm limitation than electronic triggering, thanks to its greater accuracy).
Other things to consider; A cooler spark plug might be used with a high voltage CD system, thanks to the stronger spark. This in turn helps the engine run cooler, very beneficial for high performance engines, but useful on most any TR. Also, the spark plug gap might be increased to produce a larger and stronger spark, again helping the engine fire more efficiently. Spark plugs themselves often last a lot longer, due to a "cleaner" spark and more complete combustion. And, some CD ignitions have built-in programmable rev limiters, a few even have remotely adjustable advance timing.
You'll see CD systems from Mallory, MSD, Crane, Jacobs, Accell and others (p.s. Mallory, Jacobs and Accell are actually all owned by the same parent company).
Heavier duty spark plug wiring is usually necessary with higher energy ignition systems, to carry the higher voltage and keep it contained. Often a matched coil needs to be provided, too. And, there are power supply filters available to protect the electronics of the ignition components from any charging system voltage spikes.
Personally I prefer to keep all ignition components a single brand as much as possible when making these sorts of changes. IMHO everything will be more likely to be compatible and play well together, if it all comes from the same manufacturer.
The ultimate electronic ignition is part of a full engine management system. That's found in most modern cars, centered around at least one onboard computer that's hooked to lots of sensors and, among other things, provides a mapped ignition curve to maintain highly accurate timing that's "tuned" to a variety of engine/driving conditions. In fact, if you take a look at the advance "curve" of regular distributors - whether triggered by points or electronics, and even when a CD box used - you actually won't see a "curve" at all, but more of a straight line that represents the change in advance timing over the rpm range. Only full engine management "maps" a true ignition advance curve, which can be alot more accurate. An engnine management computer also can dial in previously unheard of levels of advance when appropriate. This can take efficiency and performance to whole new levels, but necessarily adds a lot of complex wiring and electronic components in the engine compartment, and, of course, significant extra cost.
There are sophisticated aftermarket engine management systems available for TR6, just expect to spend a lot! Some of these actually continue to use a distributor, but now just as one of the "sensor", referencing where the engine is in it's cycle. Others do away with the distributor entirely, replacing it with a cogged wheel that's mounted directly to the crankshaft giving even more accurate timing capabilities.
Hope this helps!
/ubbthreads/images/graemlins/cheers.gif
First, let's narrow down what you mean by "electronic ignition". Maybe it's just me, but there seem to be a number of components that fall under that rather broad heading, and it might be written or said to mean one thing, but interpreted as another.
Many vendors offer electronic modules to replace the mechanical contact points inside a dizzy, and refer to these as "an electronic ignition". I suspect this is what you are asking about.
These modules seem to all use either magnets or LEDs with light sensors to time the firing of the ignition. But, even though the mechanical contact points are eliminated, the basic distributor function essentially remains the same.
IMHO this is really only the first small step toward an electronic ignition and Bill is quite correct: There is limited value to the relatively minor change. It might make for slightly easier starting in some circumstances and perhaps a little smoother running, but mostly just eliminates having to fiddle with point adjusments and replace a worn set occasionally. I doubt you'll see very much change in gas mileage. And, on the downside, electronic trigger modules can be a lot more sensitive to incorrect voltage or electrical system spikes. Changing to a well-matched coil might be a good idea at the same time the module is installed. (I suspect some or most premature module failures may happen when they're used with a high output "sport" coil. But this is just a guess based on very limited observation. Nothing scientific about it.)
When points get old and start wearing, the car will gradually run poorer, but typically giving you a bit of warning. With electronic ignition modules the car sometimes either runs... or not, nothing in between and little or no warning given. It seems to me an awful lot of folks who have made the change to an electronic module continue to carry a good old point set around in the glove box.... "just in case".
Next up is the distributor itself. The original Lucas are actually pretty good, but there might be some good reasons for changing: It's badly worn, other modifications to the car require a change, etc.
AFAIK, there is now only one manufacturer of replacement dizzies that will easily fit TR6: Mallory offers a Unilite model that will work and is fully electronic. There's a choice of this model: With or without vacuum advance (mechanical/centrifugal advance only).
One issue with the Mallory replacement in a TR6 specifically is that this dizzy has no tachometer drive gear (like the original Lucas dizzy does). So, installing the Mallory also means changing to an electronic tachometer (either install a replacement like a 5" indash AutoMeter or Stewart Warner, or have the stock tach converted to electronic innards for a stock look).
So, having the original Lucas dizzy rebuilt can be pretty attractive in some respects, whether sticking with points or installing some sort of electronic module inside it.
The choice of vacuum advance or non-vacuum advance is an important one, too. Non-vacuum advance is primarily for racing, such as when certain performance carbs require doing away with any vac advance.
Vacuum advance is more of a street car design, offering a bit smoother running in low- to mid-range rpm, with another key purpose of helping conserve fuel. The original Lucas dizzies all have vacuum advance (actually, with some TR6 I think it's both vacuum advance and vacuum retard, or vacuum retard only. But, generally speaking... the idea is still the same... use engine vacuum to adjust ignition timing). It's possible to convert a Lucas from vac advance to non-vac advance - i.e., to strictly mechanical/centrifugal advance - if that's wanted for some reason. However, that's not something I'd recommend to anyone seeking a street-mannered car and better fuel mileage.
Back in the good old days, an upgrade to a higher output "sport" coil with maybe 20 or 30% higher voltage and a re-curved/modified stock distributor, or possibly a Dual-Point Mallory dizzy (two sets of points to carry higher voltage than a single set), were about the extent of our choices. In some case, such as certain vintage competition classes, we still might be limited to this sort of setup.
Next step up the evolutionary ladder today is a capacitive discharge (CD) box, which ain't just for racin'. This is an additional piece of equipment and is where some real performance improvements from an electronic ignition system begin to be noticible. CD boxes often not only put out substantially stronger spark voltage, some also have "multi-spark" modes, at least up to 3000 rpm or so. These fire the plug in a cylinder several times during each combustion stroke. This makes for a more complete burn of all the fuel in the cylinder, which in turn means more horsepower and so either less fuel is used to achieve the same power output, or more power is gotten with the same fuel quantity... however you want to look at it.
In most cases, the voltage supplied to the plugs by a CD box is much higher too... ISTR about 40X increase (read that as fourty *times*, not 40%!) in the case of a stock TR4 vs. a Mallory 6AL box (probably similar with TR6 and other brands/models of CD boxes).
The much higher voltage can be used safely because the CD box sends it to the plugs, not through the dizzy where the voltage would quickly burn up points or delicate electronics. Since the dizzy is now acting only to carry and send a smaller trigger voltage, either points or the electronic triggering module can be expected to last a long time. They are protected from higher voltage wear and tear. Even standard points will often last 10X longer, but by this level of modification it just makes sense to convert to full electronic triggering, too. (Mechanical points will typically have a much lower max rpm limitation than electronic triggering, thanks to its greater accuracy).
Other things to consider; A cooler spark plug might be used with a high voltage CD system, thanks to the stronger spark. This in turn helps the engine run cooler, very beneficial for high performance engines, but useful on most any TR. Also, the spark plug gap might be increased to produce a larger and stronger spark, again helping the engine fire more efficiently. Spark plugs themselves often last a lot longer, due to a "cleaner" spark and more complete combustion. And, some CD ignitions have built-in programmable rev limiters, a few even have remotely adjustable advance timing.
You'll see CD systems from Mallory, MSD, Crane, Jacobs, Accell and others (p.s. Mallory, Jacobs and Accell are actually all owned by the same parent company).
Heavier duty spark plug wiring is usually necessary with higher energy ignition systems, to carry the higher voltage and keep it contained. Often a matched coil needs to be provided, too. And, there are power supply filters available to protect the electronics of the ignition components from any charging system voltage spikes.
Personally I prefer to keep all ignition components a single brand as much as possible when making these sorts of changes. IMHO everything will be more likely to be compatible and play well together, if it all comes from the same manufacturer.
The ultimate electronic ignition is part of a full engine management system. That's found in most modern cars, centered around at least one onboard computer that's hooked to lots of sensors and, among other things, provides a mapped ignition curve to maintain highly accurate timing that's "tuned" to a variety of engine/driving conditions. In fact, if you take a look at the advance "curve" of regular distributors - whether triggered by points or electronics, and even when a CD box used - you actually won't see a "curve" at all, but more of a straight line that represents the change in advance timing over the rpm range. Only full engine management "maps" a true ignition advance curve, which can be alot more accurate. An engnine management computer also can dial in previously unheard of levels of advance when appropriate. This can take efficiency and performance to whole new levels, but necessarily adds a lot of complex wiring and electronic components in the engine compartment, and, of course, significant extra cost.
There are sophisticated aftermarket engine management systems available for TR6, just expect to spend a lot! Some of these actually continue to use a distributor, but now just as one of the "sensor", referencing where the engine is in it's cycle. Others do away with the distributor entirely, replacing it with a cogged wheel that's mounted directly to the crankshaft giving even more accurate timing capabilities.
Hope this helps!
/ubbthreads/images/graemlins/cheers.gif
Brosky
Great Pumpkin
Offline
Kevin, all of the advice given above is sound and worth consideration before you make a move. Here is a pictorial of my electronic upgrade. The only change that I would make if I could would be to install the newer Petronix Igniter II, which safeguards against burnout from leaving the key on with the car not running.
https://www.74tr6.com/distributor.htm
Good luck........
https://www.74tr6.com/distributor.htm
Good luck........