When I rebuilt my motor, I safety wired the appropriate bolts the way the aviation guys do it. Whoever had it apart before had just looped some copper wire through the bolt heads, which I don't think was doing any good at all. I've seen it done a number of different ways, but I think the way below is the only way you'll really stop the bolts from turning.
How was it done at the Ford factory? What is really "correct"?
None of the above that I have ever see. On the production line I don't think there would have been enough time to get too fancy. It was just a single wire run from bolt to bolt. The rear ends I have pulled down had heavy wire locking groups of bolts together rather then one continues wire (they may have been apart at some time). Model A's were done the same way except the rear end dify wire ran all the way around.
So you need to make Z's, not S's.
I safety-wired the little spigot plug on the bottom of my carburetor bowl and, as I didn't want to strip the threads on my oil plug (again) by over-tightening, I very carefully drilled the hex on the plug and safety-wired that too.
I was taught that safety wiring was done to stop bolts backing out rather than keeping tension on the heads. With a leverage of half the width of the bolt head, not much tension could be applied or maintained. The neat twisting done in aviation circles will reduce the amount of backing out a loose bolt can do.
Allan from down under.
My original, never been out of the car engine just had one length of what looked like copper wire looped through all the flywheel bolts. Nothing fancy. I remember it well because I took up the main bearings with the engine in the car, and that entailed removing one flywheel bolt to get the 3rd main out.
Interesting. So the single copper wire that I thought was sloppy work was probably factory correct.
Copper wire may have been more expensive then, the same as it is today.
Henry would not have used a more expensive copper wire, unless he had a lot of wire surplus from some other use.
Maybe Henry owned one of the copper mines in the U.P. of Michigan...that way his copper would be cheap!
Safety wire pliers make quick work of the job.
Just opened up the rear end on a 25 touring that I am pretty sure has never been worked on and found the safety wiring as Mark described. Not copper but steel.
Recently, I had to go to three auto parts stores to find some safety wire, and it was made in China! I don't know how Ford did it, but I do it like Chris posted above.
The one flywheel that I had that had safety wire on the 16 magnet bolts had brass wire, looped all the way around, through all the bolt heads then twisted together, It was neatly done.
I read somewhere that Ford used brass rather than steel wire on internal components.
Ford used brass wire on internal components because it would be less prone to do any damage if it did get loose (meaning it wouldn't do any damage if it went thru the gears).
I have always used safety wire as shown in the picture at the beginning of this thread. I think Ford just strung wire more or less straight thru for a couple reasons. 1) It was quick. 2) I don't think the Ford safety wire was there to keep fasteners from getting loose. It was there to keep fasteners in place if they did get loose.
Most all the fasteners in a Model T that have safety wire should never come loose in service so long as they are properly torqued. The safety wire was probably more about saving money on costly repairs if someone on the production line occasionally didn't properly tighten a fastener here or there.
(The big exception is the studs on the front wishbone ball cap which absolutely require safety wire by their design)
Single strand safety wire is ok in this instance as the bolts are fairly close together. You should be able to get them all with less than two foot of wire. The wire should be routed in such a manner that pulling on any strand would apply tightening pressure to both bolts.
Those safety wire pliers are made in China now too and sold for about $12.95 at Harbor Freight.
They are an exact copy, but not quite as good.