1501 Banbury Court Richardson, Texas 75082
It all really began four years ago when I realized that all my
numerous past hobbies had been limited in some way by a lack of two
basic tools and the knowledge to use them. Now, I had the normal
stuff like a drill press, Dremel tool, grinder, etc., but my
retired friend Clem had a nice shop with two significant items that
I didn’t have: a small milling machine and a metal lathe. He
said a fellow could make about anything with these!
My impression was that you needed to devote a career as a
machinist to have any hope of making anything meaningful made of
metal with moving parts. However, things changed after several
engine shows with those model gas engines puffing away next to
their full size counterparts.
The rest is history with a ‘Jet’ milling machine and
13′ lathe proudly in stalled in my small workshop and three
finished model engine kits behind my belt, including Brad
Smith’s scale Maytag Upright.
Starting off slow, with simple projects which came with
instructions rather than just a confusing drawing, really helped.
When I got stuck, which was often, my friends were more than ready
and willing to offer help. I learned through experience that this
fraternity of home shop machinists have an unwritten universal code
to answer all rookie questions without the person ever realizing
that they may be meaning less or really stupid. I feel that these
great guys understand that the apprentice machinist has enough
problems living with himself.
With this as background information, my next pursuit was to
obtain a full-size upright to display at engine shows next to the
scale version. This took me to Emmett, Kansas, last year to extract
several HP uprights from the jaws of bidders undergoing a feeding
frenzy at a large antique gas engine auction. I had no idea that
Maytag collectors were that serious; an old glass gallon Maytag oil
jug went for $750. When the auctioneer finally got around to my
engines of interest, I was not hopeful of staying within my
allowance which had been pre-negotiated with the queen (my lovely,
understanding wife who is typing this article for me!).
Anyway, I escaped with just enough residual funds to pay for the
rental car at the Kansas City Airport later that day. I had flown
up from Dallas the day before with heavy-duty empty boxes,
strapping tape, and cushioning material should my mission be
successful. It was in spite of getting soaked while trying to pack
up each engine in pouring rain, time running out on making my
sold-out flight in KC, and lugging around my baggage (now over 125
pounds) through two parking lots, two airports, and two courtesy
cars (mine included).
THE RESTORATIONS BEGIN
From this rookie collector’s viewpoint, one engine was in
better shape, and on the outside each looked mostly complete. Upon
further inspection, both engines needed new con-rod bearings, main
crank bearings, new carb parts, repair of broken main bearing
housing mounting lug, cylinder fin repair on one engine, and
complete cosmetic clean-up. At the time I didn’t think too much
of it, but the engine that was in ‘better shape’ was
missing the taper pin which secures the flywheel to the crankshaft
and also the ‘ long by 1’ diameter front shoulder which is
part of the flywheel. My plan was not to worry about minor details
like this and quickly get them ready for the annual tractor and
engine show in Temple, Texas.
The engines were torn down and all parts were kept separate in
plastic tubs. Having two engines to work with gave additional
insight on what was missing, repaired, improvised, or different due
to model variations. The earlier engine (S/N 56480) had the sloped
gas tank base, and the other (S/N 56980) had the straight sides on
the base which I understand is less common. This turned out great
since it matched my scale model upright with the straight tank
sides which is pictured on the cover.
The main bearing housing is secured to the crankcase by four
bolts and is ‘sandwiched’ between the crankshaft and the
flywheel. The commutator is also trapped in the middle of this
assembly. The flywheel was separated from its crankshaft with a
little help from a dead blow hammer. I marked the larger taper pin
hole in the flywheel to insure correct reassembly later. No such
luck on the other engine (the one with no taper pin hole in the
crank). After an aggressive dead blow hammer session, I realized
what was keeping the flywheel from flying off: a massive
interference fit. There was not a safe place on the flywheel to
support some kind of arbor press, since the commutator and main
bearing bracket were in the way. I finally came up with a two jaw
bearing puller which had the jaws ground down thin to fit between
the commutator and rear flywheel hub. Photo #1 shows this set-up
and also the broken ear on the bearing housing. The puller was
rated for three tons and I bet I used most of it. When I got it off
without any explosions or breakage, I closed the shop down for the
day and mowed the lawn. Since this was my first restoration and on
top of this, on a valuable engine made 80 years ago, my
self-confidence was not where it was during the recent rewarding
model engine building activities. If something got screwed up, all
you had to do was get a fresh piece of metal, or order another
casting part from your empathetic kit supplier.
Next weekend, with renewed enthusiasm, I compared
crankshafts and determined that the problematic one was not
original, although it appeared to be well made. My plan was to use
an expansion reamer on the flywheel to allow a nice fit like the
other engine had, and drill the taper hole in the shaft.
I degreased all the castings and parts using Gunk and ‘The
Enforcer’ from Home Depot. ‘The Enforcer’ comes in a
red plastic hand sprayer and works better than anything I’ve
tried. Use gloves and warm water for the final rinse. It also
brightens metal, especially aluminum if you use a brush, and does a
good job in preparing material for epoxy or paint. This clean up
exposed a beautiful weld job on one crankcase. At first it
didn’t make sense to me why the mounting flange would break
where it did (Photo #2), but further investigation indicated that
the tank base and crankcase mating surfaces may not have been flat.
Cast iron, as I have learned the hard way in previous encounters
(fortunately!), can be very brittle and unforgiving. The other
engine also had a bad fit which may have been compensated for by
the thick gasket. I pulled out my trusty 2′ x 4′ plate
glass panel with course emery cloth taped on it and sanded away on
the tank base crankcase mating surfaces until nice and flat. Plate
glass is very flat and makes a great shop tool to get a flat
surface on a rough model casting to fixture for initial machining.
I use lay-out blue dye on the surface and when all the blue is
removed in one or two sanding passes, it’s ready. You’ll
have to remove the deflooder valve in the bottom of the crankcase
before sanding. This ingenious little device is a check valve to
automatically dump gas and oil back into the tank. Be sure to clean
it up and make sure it works, otherwise the engine may be hard
starting. Photo #3 shows J-B Weld used to fill in cylinder dings.
Be sure to use the long cure time type (four-six hours), and not
the five minute stuff, to insure high bond strength. To repair
large fin areas, a piece of steel or cast iron can be hacksawed out
and then J-B welded in place. The surfaces involved need to be
filed or cleaned to bright metal and degreased. I used a piece of
folded-over cardboard pushed between the fins to keep the epoxy in
place during set-up. Start with lower fins and work up to the top.
When cured, I used ah X-acto knife to eliminate the cardboard and
then a coarse file to contour the repaired areas. Ralph White, an
advertiser in GEM and an excellent authority on these engines,
helped me with this technique on fin repair. He offers many quality
reproduction parts for the upright and will go out of his way to
help you on any aspect of restoration or getting the engine to
run.
I don’t have the room or an air compressor big enough to
consider sandblasting. Also, I have been concerned about eroding
the metal being blasted and messing up bearing or mounting
surfaces. So, I called up ‘The Shop’ (another GEM
advertiser) and bought a quart of their ‘Rust Ender’
pictured in Photo #4. I was concerned about how well it would stand
up to heat and work over J-B weld, old paint, or Bondo. This stuff
works like other products on the market in that it is latex based
and turns rust black. One major difference is that it has
epoxy-like strength and seems to penetrate much more effectively
than other lower viscosity formulations. You need to wear gloves
and don’t get it on surfaces you want to keep bare; otherwise
you will need a file to get it off. I made the mistake of coating
the inside of the gas tank and had to resort to nasty solvents. I
painted over the entire engine, old paint, J-B weld, including
Bondo, and later it accepted enamel paint like it was supposed to
be a primer. After running the engine several hours in 100 degree
Texas heat, it passed my tests and I feel it could be superior to
other restoration methods which may not adequately address the rust
issue.
Next came the broken lug repair on the main bearing housing.
Photo #5 shows the finished product and it only cost me $25 to have
done at a local and sympathetic small weld shop. I gave him the
original gasket to use as a template, and hot rolled steel scrap
was used to arc weld back on the housing. One can save time and
money at the welding shop if the repair piece is made and the
mating surfaces ‘V’ beveled to provide more weld surface
area for a stronger joint. A ‘ belt sander or file is used to
profile the area and a 5/16‘
‘transfer screw’ is used to accurately locate the hole
before drilling. These are short stubby threaded inserts with a
sharp punch point that come in various thread sizes. Transfer
screws come in sets for each size and can be purchased for about
$12 each from machinery supply houses such as MSC or J &.L. Not
cheap, but invaluable in the shop. They are screwed into the
existing hole using a special tool supplied in the set. With the
point slightly protruding, the piece to be marked is gently
hammered against the point. Continuing on with lug repair, I did
not have to remachine the inner mating surface because I was lucky
on this one. After painting, you can’t tell there was a repair
job, except for smoother surface on profiled area. Please remember
that any manipulation of old cast iron needs to be done with severe
empathy.
The main bearing housing uses two identical 1′ long bearings
which are press fit into each end of the
15/16‘ housing bore. Getting the old worn
bearings out safely was a concern, so I called Ralph. He told me
about his ‘Impact Method’ using a brass rod through each
end of the housing and contacting the inside end surface of each
bearing. The housing is held in one hand and a dead blow hammer is
used on the rod as you rotate the housing after each blow. I was
able to ‘walk’ the bearings out of each end with no
problems. Replacement bearings are bronze and not the
oil-lite type. I have used oil-lite bearings in my scale Maytag and
they quickly ate up the crankshaft. At the time, I thought the
shaft material was not hard enough, but I learned that oil-lite
bearings can be abrasive and are not recommended for heavy or
‘impact’ load applications such as this.
The bearings pictured in Photos #6 and 7 are I.D.,
15/16‘ O.D. by 1′ long (Boston
bearing # M1215-12) and can be obtained from GEM advertisers or
your local bearing supplier. Before they are installed, grease
grooves need to be cut to match the old bearings to provide a
lubrication path to each end of the crankshaft. The groove only
goes about 1′ in from one end, otherwise you would lose the
crankcase seal so important for proper operation of a 2 cycle
engine. I used a ?’ wide cutting tool with a back and forth
scraping motion. When the rear bearing is pressed back in, the
groove must line up with the grease cup hole in the housing, then a
carefully drilled hole is made through the new bearing. The
‘captive’ groove and hole may be visible in Photo #6.
Also shown is a bevel on the bearing end to mate up with the
crankshaft radius to help with a good seal. Photo #7 shows a
Taiwan-made expansion reamer that I had to purchase when to my
dismay I found out that the crankshaft would not fit into the new
bearings. There is a little shrinkage in diameter depending on the
tightness of the press fit. These reamers can get expensive, but
the import model I needed was only $ 15, so I got the whole eight
piece set for $70, which can take you from
15/32‘ to 1/6‘
diameters, all in a nice mahogany box! With the housing positioned
vertically in the drill vise, it took two presses with the reamer
rotating at slow speed and one very small diameter adjustment on
the reamer. I was really happy with resultant crankshaft fit and
glad I made the investment in these new tools. Little did I know
how easy it was to create a restoration disaster with one of these
things (more on this later!).
Moving right along to the con-rod, I measured about 27
thousands (mils) wear in the big end bearing from front to rear and
15 mils wear on the top surface. The other rod had less wear but in
the same proportions as the first. This is a lot of wear and
explains the ‘clunking’ sound when turning over each
engine. I was concerned, however, that the crankshaft pin or
bearing housing alignment to the crankcase was really messed up
with the large amount of front to rear con-rod wear. I set up both
crankshafts on V blocks and could not detect any problems here
using a ‘last word’ dial test indicator, nor was any
crankshaft bearing misalignment observed. The mystery and concern
here thickened because I would have major binding with every
revolution of the engine if simply a new sleeve bearing was
installed using the existing hole centerline in the con-rod. The
small end bearing in the bronze con-rod surprisingly did not have
the same bell shaped wear, which added to my (normally) confused
state of mind. Anyway, Photo #8 shows one way to set up a con-rod
in a vertical milling machine. The large end is supported securely
and precisely vertical by using a stub expansion arbor held
vertically by a V block. The stub arbor through the small wrist pin
hole ensures that the other end about to be bored out is in exact
alignment. I located the boring head over the existing worn out
hole the best I could to ensure that enough remain material was
left to hold the new sleeve. After several plunge cuts with the
boring head (a really fun activity), it became clearly evident that
I was making a hole with a new centerline! Could the original rod
have been incorrectly machined 80 years ago and is this mystery
solved? Both rods turned out with ‘wappy-jawed’ centerlines
and my hope for success and fun were on the rise. I got carried
away on the second con-rod and made the hole too big. Woe is me
again, but never fear with loctite cylindrical retaining adhesive
near, which will fill diametral gaps up (high tech phrase for
sloppy fits) from 5 to 20 mils! There are several versions
available like #609 or the 450 degree high temperature #620 used
for cylinder sleeve installation. These products work very well and
their tech support people (on an 800 toll free number) are very
helpful. Your local bearing shops usually stock these.
Photo #9 shows the completed rod along with the oil groove
positioned in the middle of the top and bottom wear areas. I used a
Boston bearing #M1012-8 which is 5/8′ I.D., ‘ O.D. x 1′
long in bronze. The 1’ length is the closest size, but still
needs to be cut down to match the original con-rod width. I
installed a repro wrist pin in one engine which fit perfectly, and
had two new piston ring sets but didn’t use them since both
engines had excellent compression. Anyone need a set of rings?
The next challenge was to put a #5 tapered hole through the
crankshaft as mentioned earlier which must line up precisely with
the #5 taper holes already in the flywheel. This hole and taper pin
does three things: establishes crankshaft endplay, sets up proper
moving point-to-commutator positioning,and keeps the flywheel from
flying off (perhaps that was how the flywheel got its name). I knew
nothing about taper pins or making tapered holes, but I did know
that a bad fit or any slop could lead to breakage of the pin,
shaft, or the flywheel. With help from the Machinists’
Handbook, taper pin section, I bought a #5 taper reamer and set up
the flywheel on my larger V-block secured to the mill table. This
set-up was done to establish flywheel positioning which could be
accurately repeated later with the crankshaft installed for
drilling and reaming. Photo #10 shows the initial set-up with the
taper reamer through the flywheel holes just to establish
alignment. Perhaps you can make out in this photo that the original
holes were drilled off center! More confident than ever now, I
grabbed the mahogany expansion reamer box and enlarged the flywheel
hole diameter so the shaft had a firm fit. I only had to take off
just a little material so I quickly reamed it by hand, using an
open end wrench. The flywheel with the larger taper hole on top
installed on the crankshaft with main bearing housing sandwiched in
the middle, I repositioned the flywheel back to where it was in the
V-block set-up on the mill. Photo #11 shows this set-up with the
crank pin in the top dead center position. Since this hole
establishes crank shaft endplay, a five- thousandths feeler gauge
was used between the rear crank and main bearing housing to set
this gap and then everything was bolted down. Using a pilot point
‘center drill’ first to ensure that the drilling of the new
crank hole would be started ‘on course,’ I then went to a
letter ‘A’ size drill and completed the hole. I switched to
a ‘ drill and drilled about 1/3 way
though the shaft. This was done to help out the reaming job. Now
with the reamer chucked up, I rotated the mill spindle by hand and
completed the job while also cutting fresh iron in the flywheel to
ensure a tight taper pin fit.
Next came fitting of the pin. Photo #12 shows the helical flute
reamer and a hard to find 5′ long #5 pin next to the newly
fitted 2′ long pin. Ralph recommended the 5′ length since
the original hole or newly reamed one would fit a #5 taper pin on
the larger diameter side so I bought one from him. He was right as
I had to cut off each end to achieve solid seated fit and still be
about flush with the O.D. of the flywheel hub.
The suspense by now was too great; I just had to find out
whether everything would go back together and at least be able to
turn over the cranks. Each engine was reassembled and to my
surprise no binding and no clunking and each with just a little
endplay like you want, except for one thing, the flywheel which I
reamed out now had about a 15 mils wobble whereas before you could
not detect any. Normally a total indicator readout of less than two
or three mils front to rear at the periphery of a flywheel is
undetectable but 15 is really bad. The previous reaming I did by
hand with a wrench caused this; now a lesson learned the hard
way.
The restoration continued with making 24 new bolts (12 per
engine) replicating the original thick hex heads using free
machining ‘C12L14’ leaded steel in ‘ hex stock. This
stuff machines effortlessly to a chrome-like finish. The threads
were cut using a die and holder in the lathe’s tail stock. The
first bolt took me 35 minutes and my best time got down to 4.7
minutes (taking 70 mil cuts). I also discovered that the cylinder
head bolts need to be a little shorter than the rest and may need
to have their head diameter reduced slightly to clear that tight
space. Photo #13 shows the finished bolt and the brilliant finish
you can achieve. I ordered some carb parts and several commutators
from the Maytag man in Rochester. The commutators are a thing of
beauty (Photo #14). A tip he had to prevent the locking-screw from
burring the phenolic was to make a small rounded brass foot to
thread on the end of the screw. Trips to several paint stores found
the recommended Rust-Oleum brand ‘Royal Blue’ #7727 and
‘Regal Red’ #7765 enamel paint. I bought a 12 oz. spray can
and 8 oz. can (for brushing) of each color which was more than
enough for both engines. This paint went on very well over the
‘Rust Ender’ and dries to a high gloss, really tough
finish. New gaskets were cut and both engines were assembled side
by side using ‘RTV Blue’ sealer. I was warned not to over
tighten the main bearing housing bolts since its bolt lugs were
unsupported and do not seat against the crankcase. I haven’t
scrutinized any other engines armed with this knowledge, but I bet
there is a high percentage of remaining uprights with either broken
or repaired lugs.
The scale upright has a walnut skid with electronic ignition
hidden inside which I designed. I scaled up this same skid design
for the full size version so it would match.
The one upright fired up and ran like a top along with its scale
look-alike putting away at the Texas show. The other upright
remained home with a bad wobble and missing that shoulder on the
flywheel. I finally decided to call Ralph and found out that this
protrusion was easily broken so it normally ended up ground off
flat with the end of the main flywheel hub like mine was. This
shoulder, I understood, was cast into the flywheel to increase its
contact area with the crankshaft which is not very much to begin
with. He said it was pretty straightforward to make a sleeve and
enlarge the existing ‘ flywheel hole for a press fit of this
new sleeve.
This was GREAT news, as I could remedy my concern for both the
missing shoulder and correct the wobble I caused. The flywheel was
mounted in the lathe and centered in the four jaw chuck with the
jaws reversed. (And boy was I glad that Clem talked me into getting
a 13′ lathe!) I bored out the flywheel hole to 1.25′ and
then made up a new sleeve with 5/8‘ I.D.
bore and loose hand fit in the flywheel (Photo #15). Good old
Loctite #609 was used, permitting easy hand positioning and then
let set-up for a couple of hours. Photo #16 shows the flywheel back
in the lathe ready to be accurately bored out to produce a tight
sliding fit on its mating crank -shaft. Ten minutes later I was
happier than a clam with the flywheel re-pinned back on the engine
with a new shoulder and devoid of any wobble!
The final product is pictured in Photo #17 next to the
‘Detroit Coil’ which was originally used to power these
engines. I made two coils which was a research and development
project in itself. The system uses four AA nicads and will run the
upright for about 20 hours before needing a change. Photo #18 shows
the Detroit Coil just before final assembly. The finger joints in
the 3/8 thick light oak were a lot of fun and
easy to make using a 3/16‘ diameter end
mill with all four sides sandwiched together in the mill’s
vise.
I realize this article was long, but I felt it was necessary to
pass on some of these techniques and knowledge before they are
forgotten or lost. Special thanks to Carl, Ralph, Brad , and
Clem.
WARNING: If you decide to get involved with a machine shop,, it
can be extremely contagious and can easily change a current course
of collecting things to making things.
