Author Topic: Ignition coil numbers  (Read 3311 times)

GaryL

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Ignition coil numbers
« on: March 23, 2009, 02:36:14 AM »
Was the only function of different numbers stamped on coils to coordinate the correct bracket required? Were a 293, 298 and 270 coil bracket all different. Obviously the 208 mounted totaaly different than the V* brackets. I realize the 270 coil bracket angles more than the 298 coil bracket. But why was the 293 different? A lot of questions here.

The Chassis Service Manual only lists 1 value for coil primary and secondary resistance so the coils must have been the same.
Gary

Lemans Blue X33. DZ, M20, manual steering. Only BU code rear end is original.

JohnZ

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Re: Ignition coil numbers
« Reply #1 on: March 24, 2009, 03:28:17 PM »
Coil part numbers in the Assembly Manual are unrelated to the coil itself - they're for the "coil assembly", which included the mounting bracket; all coils arrived at the assembly plant pre-installed in the mounting bracket, which differed depending on the application.
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69Z28-RS

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Re: Ignition coil numbers
« Reply #2 on: March 24, 2009, 06:20:58 PM »
Wlw...   that is very interesting...   and implies that the coil manufacturer also mfg'ed the bracket?  (or had it made by a vendor to GM specs to sell to chevy with the coil).... ?

I removed my original coil/bracket in the '70 when I installed the Mallory Rev Pol with Judson Electronic magneto.... I'm sure it's in the garage 'somewhere'....   *:) ..but finding it might be a whole different story!
Does anyone have PN and/or a photo of the correct coil/bracket for the '69 Z28 so at least I know what to scrounge in my garage/shop for?  :)
Gary W / 09C 69Z28-RS, 72 B 720 cowl console rosewood tint
69 Corvette convertible, silver/black 350 hp,
60 Corvette white/red, 72 Corvette coupe, '70 Mach I 
90 ZR1 red/red #246, 90 ZR1 white/gray #2466
72 El Camino, '55-'56-'57 Nomads, '55-'57 B/A Sedan

GaryL

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Re: Ignition coil numbers
« Reply #3 on: March 25, 2009, 02:15:01 AM »
Wlw...   that is very interesting...   and implies that the coil manufacturer also mfg'ed the bracket?  (or had it made by a vendor to GM specs to sell to chevy with the coil).... ?

I removed my original coil/bracket in the '70 when I installed the Mallory Rev Pol with Judson Electronic magneto.... I'm sure it's in the garage 'somewhere'....   *:) ..but finding it might be a whole different story!
Does anyone have PN and/or a photo of the correct coil/bracket for the '69 Z28 so at least I know what to scrounge in my garage/shop for?  :)

The coil for flat hood is (1115)298 and for the cowl hood is (1115)270. I was wondering about the number on the bracket itself.

I wonder if the 2 brackets have a number?
Gary

Lemans Blue X33. DZ, M20, manual steering. Only BU code rear end is original.

69Z28-RS

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Re: Ignition coil numbers
« Reply #4 on: January 29, 2013, 04:55:57 AM »
Was the only function of different numbers stamped on coils to coordinate the correct bracket required? Were a 293, 298 and 270 coil bracket all different. Obviously the 208 mounted totaaly different than the V* brackets. I realize the 270 coil bracket angles more than the 298 coil bracket. But why was the 293 different? A lot of questions here.
The Chassis Service Manual only lists 1 value for coil primary and secondary resistance so the coils must have been the same.
The fact that the resistance to dc current is the same, does not necessarily that the coil windings are the same number/ratio, or that the current capacity during fire is the same.   Increasing the wire size would reduce the resistance, while increasing the wire length (# coils) would increase the resistance and affect the step up voltage on the secondary...  so Delco Remy must have been adjusting some of the parameters to affect stronger fire, or some other parameter while holding the resistance the same?
So I've still got the same question re how do I identify the proper coil for my cowl inducted 302?

Gary W / 09C 69Z28-RS, 72 B 720 cowl console rosewood tint
69 Corvette convertible, silver/black 350 hp,
60 Corvette white/red, 72 Corvette coupe, '70 Mach I 
90 ZR1 red/red #246, 90 ZR1 white/gray #2466
72 El Camino, '55-'56-'57 Nomads, '55-'57 B/A Sedan

woodsman1172

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Re: Ignition coil numbers
« Reply #5 on: January 29, 2013, 05:18:22 AM »
The body of the coil cannister will have '270' embossed on it, the bracket has a steeper angle and a notch out of the top rear edge.

KurtS

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Re: Ignition coil numbers
« Reply #6 on: January 29, 2013, 05:06:31 PM »
I understand the bracket would be different, and thus different bracket coil assembly, but why a different coil?
Or did someone at GM get lazy and just use an already released assembly with a correct bracket and a close coil. Therefore they didn't have to release a new part.
Kurt S
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69Z28-RS

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Re: Ignition coil numbers
« Reply #7 on: January 29, 2013, 05:32:59 PM »
Thanks for the comments:
I did a little digging last night, and found some old posts (one good one by John Z) which basically said that 'cowl induction cars go the 1115270 coil (assembly).    which makes sense given the installlation requirements that the bracket would be different.  both 302, with cowl, and L48 (Z11) at least used the same 270 'assembly'.   also found references that 'high performance' cars used the 270 coil..  so there's some discrepancy, or illogic, or something that still contains some confusion, mostly re the use of the coil/bracket assembly as one PN.   Strange...  :)    so I need to make sure I have a coil with the 270 embossed on the side to put in my cowl-based bracket..  :)
Gary W / 09C 69Z28-RS, 72 B 720 cowl console rosewood tint
69 Corvette convertible, silver/black 350 hp,
60 Corvette white/red, 72 Corvette coupe, '70 Mach I 
90 ZR1 red/red #246, 90 ZR1 white/gray #2466
72 El Camino, '55-'56-'57 Nomads, '55-'57 B/A Sedan

KurtS

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Re: Ignition coil numbers
« Reply #8 on: January 31, 2013, 06:54:44 AM »
I've had the same thoughts, but never researched it to a conclusion.
Kurt S
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