coil location

[houckpa]

With all of the info on coils overheating, is there any problem with locating it remotely. Say on the bulhead with the wires running to it. Does it have to be mounted on the engine to ground it.
Thanks
Brad

[Don Moyer]

Brad,

The coil does not need to be in contact with the engine to operate. In fact, the way coils fail is to short through defective internal insulation and ground out to the block. For this reason, mounting a coil remotely from the block would help a coil which may be on the verge of failing to work somewhat longer. I'll let you decide whether or not that would be an advantage.

In terms of heat build-up, the few reports that we've received from folks who have moved their coils to a bulkhead indicate that the coils do not operate much cooler.

We prepared the following technical note on the subject of coil temperature, including a few things that have historically caused coils to overheat in the Atomic 4:

1) Sometimes the Bakelite piece on the points which rubs on the rotating shaft of the distributor wears to the degree that the dwell value increases beyond the specification of 31 to 34 degrees (for late model engines). Higher dwell angles mean longer charging times for the primary circuit within the coil, and higher heat. Early model engines start out with a slightly higher dwell angle (38 degrees), so we hear of more early model engines burning up coils due to high dwell angles than late models.

2) Higher than normal heat build-up within small engine compartments. This cause factor is obviously more common in areas with high ambient temperatures.

3) Coils will operate somewhat hotter after electronic ignition systems are installed. However, we are informed by the manufacturer of the Ignitor system that any increased heat build up as a result of electronic ignition is well within the design specifications of any coil that has not been previously damaged mechanically, by losing internal oil through rust, or by prior overheating.

Mounting the coil remotely from the heat of the engine (even outside the engine compartment) is a good idea in general. However, unless you're operating in high temperature zones like Hawaii, Florida, the Islands, etc.) you shouldn't have to relocate the coil. We would therefore have some concern that if you relocate the coil as a remedial action in the aftermath of a premature coil failure, you might miss the real reason that your coil failed.

Best regards,

Don