Ken Brown's Bearing Party
|Subject: Pouring Bearings on old
"Hit & Miss" Engines
Situation: On September 18-19, 1998 a group of old engine enthusiasts met
at our home in Northern Vermont in order to learn the process and also
repair bearing damage on a total of six engines. Most of the collectors,
who were from both Canada and the U.S., were relatively new to the hobby
and none had ever poured bearings in the past. Our instructor was an eighty
plus year old Canadian gentleman who had operated a small foundry in years
past. His handshake was like putting your hand in a steel vise and his
limited English was interpreted by our bilingual Canadian friends for the
non French speaking collectors. We all understood when he would say "you
kill yourself doing that!"
Disclaimer: After giving consideration to the litigious nature of the human
race it was decided to provide the following disclaimer concerning this
narrative: Virtually every procedure and material mentioned in this
narrative will cause immediate death, dismemberment, disability, or loss of
consortium such that massive doses of "Viagra" will provide little remedy.
By even reading this material you are agreeing to having been forewarned of
these possible consequences!
The General Process: From information gained from the Internet Stationary
engine list and from extensive explanation by our instructor it had been
determined that there were many variations of the basic process. The
variations were based on available equipment, materials, the specific
bearing application, and the machinery being repaired. It appears that the
bottom line is that "if it works" you did it the correct way. When
possible, I will mention the alternative methods in this narrative.
The Cautions: It appears that the two primary means of sustaining injury in
the process are as follows: 1. "Splatter" of the molten metal when
transporting or pouring the bearing. 2. Moisture within the mold coming
into contact with the molten metal and causing steam and resultant pressure.
This steam generated pressure can cause the molten metal to be forced out of
the inlet orifice or "pouring hole" or cause a minor explosion of the metal
as it breaches the confines of the mold.
Any contact between the molten metal and moisture will cause a "splatter"
similar to water contacting bacon frying in a hot pan. Most hazards can be
avoided by insuring that all primary and adjacent work surfaces are
completely free of moisture and that the movement of the molten metal is
Protective Clothing: Rule one is to cover as much bare skin as possible.
Try to use leather boots and that your pants legs are outside the boots as
opposed to being tucked into the boots. Open boot tops provide a nice
opening for molten metal to reside! We used an old welding mask with clear
glass substituted for tinted glass. Safety goggles would be minimum eye
protection. Welder's gloves or at least heavy gloves with the openings
taped shut around the shirt sleeve at the wrist are a must. Use a welders
bib if you have one. I used an old "Nomex" (fire-retardant) suit that had
been getting moldy in the closet since my hydroplane racing days are long
since past. While these precautions may seem "overkill" to some.it worked
for us as everyone in the group went away without pain or injury. Besides,
we didn't know what the hell we were doing!
The Task At Hand: All of the six engines ranged in size from 1 HP to 4 HP
and required the replacement of "split" bearings for the crankshaft or
piston rod. The old bearings were either smashed, missing, or severely
worn. Two engines had the flywheels still attached to the crankshaft as
removal of the flywheels presented a high probability of damage to the
components (boy! were they frozen on!).
The Equipment and Materials: The following is a list of materials and
That we used. This list may well vary depending on available resources.
Babbitt Material: The babbitt alloy material was provided by our volunteer
instructor in the form of five pound "slugs" in the shape of a bagel. The
material is available from a number of sources to include "Hit & Miss
Enterprises" in Ohio. We also used fragments of old bearings that had been
saved when the engines were dismantled.
Dam Material: The dam material used for containing the molten metal was
also provided by our volunteer instructor and was in the form of a ½ inch
square light brown and waxy material that was formed into a coil. This
pliable material had the general appearance of "oakum" used between the
planks on wooden boats. It is suspected that the specific material we used
may well have been decades old. The modern equivalent is called
"Babbitrite" and is evidently available from the Mc Master Carr company in
the U.S. Stationary engine list members indicated that they have used
everything from modeling clay to children's "Play Dough" with successful
Equipment: Crucible: We used an electric crucible similar to the type used
to melt lead used in casting bullets. I would suspect that almost any
suitable container using a controllable heat source would do the job.
Ladle: The ladle we used was a short handled cast iron ladle with a wooden
handle for heat insulation. The ladle should be of sufficient size to enable
the individual pour in one movement. Acetylene Torch Set: An acetylene
torch set was used to heat components and also provide the mold release
agent in the form of carbon black. Stationary Engine list members indicated
the use of everything from small propane torches to high heat blower guns
used in paint removal. All indicated successful results? Alignment Tools:
In each case we used the piston and piston rod inserted in the engine piston
sleeve as a means of achieving proper alignment with respect to the piston
rod and the crankshaft. An alternative would be to use a jig of some sort
to insure a 90 degree alignment between the crankshaft and the piston rod.
Spacer Jigs: These jigs were used to gain proper spacing between the
crankshaft surface and the base such that the bearing would be uniform in
dimension. The jigs used varied from engine to engine. When a spacing stud
was already in place on the engine base all that was required was a short
wire wrap on this stud to provide an "oiling groove"
in the finished bearing. If no such stud was present we used an adjustable
support platform placed under either the crankshaft itself or under the
flywheels if they were still attached to the crankshaft. The support
platform was made of wood with the "support" surface shaped to the contour
of the shaft or flywheel to ensure stability of the components. Fake Shims:
Temporary shims made of hardwood were used as all two piece bearings were
poured as a unit. The hardwood shim was .125 in thickness and had four
grooves cut on the surface that set against the crankshaft surface. These
grooves allowed the molten metal to flow into the lower bearing space. The
temporary wooden shims would be later replaced with metal shims when the
engine was reassembled. Heat Gun: Our instructor did use one piece of
modern equipment in his process. A hot air heat gun similar to a women's
hair dryer was used to heat the crank journals and also maintain heat on the
metal just prior to the pouring of the bearing. The hot air gun was used as
it provided uniform heating that would not alter the qualities of the crank
metal by overheating those areas.
The Actual Procedure: A 1 ½ HP Massey Harris base was placed on a perfectly
flat concrete surface. All metal surfaces in the immediate vicinity of the
bearing surfaces were cleaned of grease and moisture with great care. We
used "Acetone" as a cleaner and the hot air gun after the Acetone had
completely dispersed. Two short pieces of #10 gauge wire were twisted into
an elongated "X" to form the oiling groove in the finished bearing. This
"X" was bent to the contour of the bottom of the bearing mold such that it
laid perfectly against the surface. It was then removed, covered with
carbon black using the acetylene torch, and replaced in the bottom of the
mold. The crankshaft had carbon black applied to the journals. It was then
placed in a wooden jig that supported the shaft directly over the bottom of
the bearing mold (the engine base) at the same spacing indicated by the old
fragmented bearings. The wooden jig was situated at the very end of the
crank shaft and sat on the concrete floor. The jig had a wide base for
stability and was adjusted for height using shims between the jig and the
floor. The piston rod, which was attached to the piston located in the
sleeve, was then attached to the center journal of the crankshaft. The 90
degree alignment between the crankshaft and the piston rod as well as the
desired bearing spacing were triple checked for proper dimensions. The
wooden temporary shims were placed into position. A perfectly clean and dry
grease cup base was installed in the bearing caps after the threads were
coated with carbon black. The interior of the grease cup base and the
interior of the bearing cap were treated with carbon black prior to the unit
being loosely bolted into place on top of the crank journal and temporary
wooden shim. The moldable dam material was placed firmly around both upper
and lower openings of the "pour" space. Care was taken not to push the dam
material into the desired pour space. The metal surfaces were initially
heated with the hot air gun and this process was completed using the
acetylene torch. Care was taken not to disturb the dam. The hot air gun
was then used again to keep the metal warm until the very moment of the
metal pour. To be honest, the metal was more warm than hot, however, no
pour voids were encountered. The babbitt metal had been melted such that it
was molten and had a blue sheen to the surface. The molten metal was ladled
into the grease fitting base and eventually filled both the lower and upper
mold areas. The bearings were allowed to gradually cool over a couple of
hours and when the caps and temporary shims were removed the excess material
was either filed or shaved. The wire forming the oil grooves was removed
and the operation was complete. We eventually completed six engines over a
two day period.
Alternative Methods: Evidently some people prefer to pour only one half of
the bearing at a time. Some people like to pour the complete bearing on a
"dummy" journal and then cut the bearing from the dummy surface. I would
think that the chosen method is more dictated by the placement and type of
bearing than anything else.
Conclusion: Preparation was 95% and bearing pouring was 5% of the
Note: If I have confused you or myself with my descriptions of the bearing
pour I will be most happy to clarify any point via direct email. In spite
of our success, I tend to believe we gained only a small fraction of the
knowledge required to make a living in this profession! Thank you for your
interest. We would also appreciate any additional information you might
care to add to our knowledge base.