Ignition Coil Specifications?
Thread Starter
Racer
Joined: Sep 2019
Posts: 349
Likes: 44
From: Spokane, WA
Ignition Coil Specifications?
I have searched, as always, but have come up with a range of specifications for a breaker point coil for a 1969. Members have stated numbers on the the primary side from 1.5 - 2.0 and secondary from 3000 - 20,000. At this point, I am not sure what the true specifications might be.
My current coil, standard replacement style, is 1.8 ohms primary and 6450 secondary. Good? Bad?
Thanks
Sam
My current coil, standard replacement style, is 1.8 ohms primary and 6450 secondary. Good? Bad?
Thanks
Sam
Last edited by Sammy T; Apr 14, 2020 at 10:44 AM.
Le Mans Master
Joined: Dec 2006
Posts: 8,837
Likes: 1,028
I "think" there are two types that year.
TI Coil is like 1 ohm, and the other would be higher.
Ideal, regardless of what a book might say, The combo of coil and resister wire should be 4 amperes draw.
Without checking notes, I do NOT recall that specification of the resister wire.
TI is more complicated.
TI Coil is like 1 ohm, and the other would be higher.
Ideal, regardless of what a book might say, The combo of coil and resister wire should be 4 amperes draw.
Without checking notes, I do NOT recall that specification of the resister wire.
TI is more complicated.
Thread Starter
Racer
Joined: Sep 2019
Posts: 349
Likes: 44
From: Spokane, WA
I "think" there are two types that year.
TI Coil is like 1 ohm, and the other would be higher.
Ideal, regardless of what a book might say, The combo of coil and resister wire should be 4 amperes draw.
Without checking notes, I do NOT recall that specification of the resister wire.
TI is more complicated.
TI Coil is like 1 ohm, and the other would be higher.
Ideal, regardless of what a book might say, The combo of coil and resister wire should be 4 amperes draw.
Without checking notes, I do NOT recall that specification of the resister wire.
TI is more complicated.
You are right, there were two types and fortunately (or unfortunately depending on how you look at it) I don't have the K66 option. I have a minor miss at light throttle and am working my way through all the troubleshooting. All ignition wires are good. Plus are gapped and are correct for the engine and year. Dwell is 30. Cap/rotor are new. Just left with coil and idle circuit (which I set with a vac gauge).
Race Director
Joined: May 2006
Posts: 18,692
Likes: 2,572
The 1969 Chevrolet Chassis Service Manual in the Engine Electrical section in the back of the manual states for the original Delco coil the primary resistance is between 1.77 and 2.05 ohms.
The secondary resistance is between 3,000 and 20,000 ohms.
The secondary resistance is between 3,000 and 20,000 ohms.
Thread Starter
Racer
Joined: Sep 2019
Posts: 349
Likes: 44
From: Spokane, WA
I saw that, but Willcox had stated different values, particularly for the secondary where Ernie said that less than 11k was a problem.
Otherwise, my coil is in spec. Maybe a little weak on spark, but in spec.
Otherwise, my coil is in spec. Maybe a little weak on spark, but in spec.
Thread Starter
Racer
Joined: Sep 2019
Posts: 349
Likes: 44
From: Spokane, WA
Got a standard replacement from one of our vendors. The freakin thing was blue. Blue! Why? Website showed black. Anyway, testing that coil. Primary 1.7. Secondary 8100. Still wondering why Willcox stated 11k or less is bad.
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Thread Starter
Racer
Joined: Sep 2019
Posts: 349
Likes: 44
From: Spokane, WA