Ford V8 spark plugs

[Hanno Spoelstra]

Next question: are the spark plugs fitted with resistors/suppressors? I'm asking because currently my truck has a mixture of 15 kOhm and 12 kOhm suppressors which is no good whichever way one looks at it. So they will be replaced along with the wiring itself and spark plugs.

In the various manuals I see either leads fitted directly to the spark plugs, and I see leads fitted to a suppressor which is fitted on top of the spark plugs.

The spare parts lists 10 kOhm suppressors - as far as I can see this was standard, correct?

parts list-suppressor.jpg

[David Dunlop]

Hanno. There is a better than likely chance any photos in the military manuals showing spark plug leads with no suppressors were simply lifted from available images in civilian manuals to save time in getting the military manuals published. The high tension systems of these vehicles would produce a lot of RF Interference that could affect wireless communications. The military went to great lengths to shield specific built wireless vehicles to avoid interference with the wireless operations contained within, but they also had to be sure any RF interference generated by passing transport vehicles of any type were also held to a minimum. 10K would seem to be the standard from what I recall, but it might be interesting to see what information could be gleaned by tracing listed replacements in the manuals over time. Each time a suppressor was replaced by a new part, were they getting more aggressive with the suppression, or backing off?

I have heard of situations where the high tension systems, of some vehicles, were spitting out so much RF Interference, the vehicles movements in the field could actually be tracked with RDF equipment. Probably another good reason to keep them as quiet as possible.


David