Homemade Cylinder Ridge Reamer/Cutter

Fri Nov 21, 2008 4:26 pm

Because of no air filters on early vintage vehicles, with dusty roads, rings were changed as recommended by manufacturers, at about 10,000 miles on a new or rebored engine, & about every 5,000 - 8,000 miles on used car engines, or earlier, if one left enough blue smoke on the highway to only allow 10% visibility for the vehicle driver following in the rear.

Removing cylinder ridges for vintage vehicles was performed often, sometimes by the first vehicle mechanics, the local blacksmiths.

Making this tool by hand requires a bit of patience, dexterity, & skill; using this tool also requires a bit of patience, dexterity, & skill.

Years ago I witnessed seeing this handmade cylinder ridge tool made, and witnessed seeing cylinder ridges removed as described below.

Since that time, I made a couple of these tools until I found out that ridge reamers were for sale & could be bought.

1. Materials/Equipment Needed:
a. Buy an approximately 8" long mill file, or better yet, get a "used" approximately 8" long mill file.
b. Get a bench grinder; either hand crank, or electrically operated.
c.. Get a bucket of water for dipping the hot file often when grinding parts of the file's surfaces smooth, so as not to overheat & destroy the temper of the file.
d. Get some electrical tape or masking tape.
e. Get an oil soaked rag or paper towel.
f. Optional: Pencil & paper to draw a rectangle indicating how to prepare the four (4) sides of the tool.
2. Homemade Tool General Description:
a. This tool, made from a mill file, has two (2) approximately 1" wide file surfaces, opposite each other, which one may call Side (A) & opposite Side (B); &,
b. Also two (2) approximately 1/8" thick file surfaces, opposite each other, which one may call 1/8" Side (1) & opposite 1/8" Side (2); &,
c. This mill file tool also has a point on one (1) end which one may call the top; &,
d. Also a flat end on the opposite end which one may call the bottom.
3. Position of Tool When in Use:
a. With the engine securely fastened in place, & with the file held vertically in a cylinder, approximately 90 degrees to the crankshaft, the file pointed top end will be pointed in the direction of the top of the engine, (towards the sky), & the file bottom will be pointed towards the bottom of the engine, (i.e., towards the crankshaft).
b. Side (A), 1" wide, will rest against the cylinder wall's circumference, & Side (B), 1" wide, will be facing the center of a cylinder.
c. Side (1), 1/8" wide, will be the cutting edge when the vertical file is moved in the clockwise direction, (or counter-clockwise direction, depending which is more comfortable for a right or left handed person), & Side (2), 1/8" wide, will be the opposite side trailing edge.
d. The top half of the file, (approximately 4" in length), will remain as; e.g., no grinding of the file's surfaces; hence, wrap the top 4" half with tape for use as a tool handle.
e. The bottom half to the file, (approximately 4" in length), will be ground such that the file's "teeth" on some sides are ground smooth, as indicated below in Step 4.
4. Making & Grinding the Tool:.
a. On the file corner between the 1" wide Side (A), & the 1/8" wide Side (2) trailing edge, remove all of the file's teeth until a smooth metal surface is obtained such that it will slide on the cylinder wall without scratching it.
(Remember to dip the file in the water bucket when the file gets hot from grinding).
b. At the file corner between the same 1" wide Side (A) , & 1/8" wide Side (1) cutting edge, remove all of the file's teeth on Side (A) first until a smooth metal surface is obtained such that the 1" wide Side (A) part of the corner will slide on the cylinder wall without scratching it.
c. The 1" wide Side (B) & the 1/8" Side (2) will not be ground at all. Side (B) & Side (2) teeth can remain as is because Side (B) & Side (2) will never touch the cylinder wall when used properly.
d. On the 1/8" wide Side (1) cutting edge, remove all of the file's teeth, first at 90 degrees. Next to prepare the cutting edge, grind this 1/8" wide Side (1) cutting edge such that instead of the corner between Side (1) & Side (A) being 90 degrees, it should be about approximately 85 degrees; e.g., when finished, the untouched 1" wide Side (B) should be slightly less in width than Side (A) against the cylinder.
e. Exercise great care to provide a straight, sharp cutting edge straight for the bottom 4" length of the file.
5. Using the Tool:
a. First, turn the crankshaft such that the piston is lowered & place an oily rag on top of the piston to collect metal ridge shavings.
b. Next, while holding the tool's upper half wrapped with tape, firmly grasp the tool with both hands & hold it in the vertical direction.
c. With uniform pressure, slowly slide the lower cutting edge of the tool in the horizontal direction only, just like scraping the side of a mixing bowl with a spatula. Do not try to cut too deep at first.
d. Work slowly & carefully, removing a small amount of the ridge on about 1/4 of the circumference of the cylinder ridge at a time, until one can get the "feel" for it.
e. Be carefull not to scratch the cylinder wall below the ridge.
f. Continue to cut the cast iron ridge until the ridge is cut down smooth & level with the lower part of the cylinder.
g. It is best to leave a very small ridge the thickness of a sheet of paper than to cut the top of the cylinder ridge too deep.
h. As far as cylinder ridge thickness is concerned, the thickness can be better determined & felt with one's finger sliding upwards on the cylinder wall than by sight.
i. Good luck -- if one thinks this hand cutting of ridges requires skill, try scraping babbitt connecting rod bearings & main bearings on the poured babbitt bearings of the 1920's & 1930's engines which were made this way prior to the more modern Cub insert bearings which we still have today.

Hope this helps some day if one does not have a ridge cutter in one's tool box.

H. L. Chauvin