'Sorry, this question is for a Model A engine, but is also applicable to Model T's. We cannot find 0.120" over-sized rings to fit the older aluminum pistons in my friend's engine. He was too cheap to bore up to 0.125" and simply buy that size ring set. So, guess who gets to solve this problem!!! Rich at Antique Engine Rebuilding in Skokie, Illinois, recommends simply hand-filing 0.125" over-sized rings to attain the proper end gap using a vertically-oriented file locked in a vise. It must be a small file, such as an ignition points file. That may be too small, though. Is there a special file I should look for to accomplish this time-consuming task? An ordinary hardware store metal file? Coarse or fine grit?
Thanks in advance.
You can do it with an ordinary hardware store metal file. The rings I've filed were cast iron and was rather soft to file - be careful and measure often. Not very time consuming since you won't need to file all that much - the .125 oversize rings are just .005x3.14= 0.0157" oversized compared to what your friend needs.
Just be carefull not to break the rings,they cant spread out but so far.But I do believe you can use something a bit bigger than a point file as that would take forever!
Would grinding be better?? Bud.
Clamp a file in a vise, on edge, horizontal. Hold the ring by it end gap, stradle the file, and pull the ring to file the ends. You will be filing both ends at the same time. Push on the ends toward the file as you pull. It only takes a few strokes. Insert the ring in the cylinder bore to check the ring gap.