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Coil question
- Thread starter jerrybny
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Jerry, I am pretty sure the 73 is a ballasted system. My 73 had an actual big ugly white ballast mounted on the block. I stripped all that off, bypassed the ballast wire in the new harness and went with an internally ballasted Sport Coil.
Bill
Bill
Brosky
Great Pumpkin
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I thought that the 74-76 used the ballast wire in the harness.
This is from a recent thread of mine asking about the Lucas Sport Coil:
The 74 & later TR6 may already have a different coil such as the Lucas 15C6 & ignition system. This coil is made to be used with an external ballast. A "sport" coil might be substituted by bypassing the existing ballast. It's not likely that the conversion would produce noticeable gains on the later systems.
For use with points, a "sport" coil such as the Lucas DLB105 which is internally ballasted, has a primary resistance of around 2.6 ohms. The standard internally ballasted standard coil such as the Lucas HA12 has a primary resistance of about 3.1 ohms. The exact numbers will vary with the particular models of coils being compared.
The sport coil would draw about 18% more current through the points, give about 6% increase in available voltage & around 18% increase in spark energy. Many folks feel that the increased output offsets the somewhat shortened point life. There may be a slight benefit from opening the plug gaps .005" to .010".
https://www.britishcarforum.com/ubbthread...p;page=2#229057
This is from a recent thread of mine asking about the Lucas Sport Coil:
The 74 & later TR6 may already have a different coil such as the Lucas 15C6 & ignition system. This coil is made to be used with an external ballast. A "sport" coil might be substituted by bypassing the existing ballast. It's not likely that the conversion would produce noticeable gains on the later systems.
For use with points, a "sport" coil such as the Lucas DLB105 which is internally ballasted, has a primary resistance of around 2.6 ohms. The standard internally ballasted standard coil such as the Lucas HA12 has a primary resistance of about 3.1 ohms. The exact numbers will vary with the particular models of coils being compared.
The sport coil would draw about 18% more current through the points, give about 6% increase in available voltage & around 18% increase in spark energy. Many folks feel that the increased output offsets the somewhat shortened point life. There may be a slight benefit from opening the plug gaps .005" to .010".
https://www.britishcarforum.com/ubbthread...p;page=2#229057
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jerrybny
Jedi Knight
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I measured the resistance of the wire that goes from the fuse box to the + terminal of the coil. On the 200ohm scale I got .3 I found a wiring diagram for a 73 TR6 and it showed that a 73 had a resister wire. So I am assuming that the previous owner must have replaced the original wire. So I guess I can get the Lucas Sports Coil. Everyone agree? Thanks /ubbthreads/images/graemlins/cheers.gif