Re: JB Wield
you can use those rods (the trade name is "Alumiweld," available at Harbor Freight) to actually "make" threads.
i haven't tried it in an engine, but i made some fender struts out of aluminum. i wanted steel eyebolts at the end that bolts to the axle, so i drilled a hole, dropped a piece of alumiweld in, then put the eyebolt in.
heated it up and when it started to melt, pushed the eyebolt down with pliers, and the alumiweld squished out the top.
since the bolt is steel, the alumiweld doesn't stick to it, and you can thread the bolt out.