I've always wanted a REALLY big 2-banger "popper" engine
but don't have either the space or the bucks to get one, I'm going to
sort-of replica of the engine in a Hart-Parr 30-60 tractor.In case you're unfamiliar
the original Hart-Parr 30-60
tractor, here's a YouTube video:
60 HP engine used in that tractor has a bore of 10 inches (254 mm) and
of 15" (381 mm), giving a swept volume of 2356.2 cubic inches (38611.2
cc). A nice little engine.
has a flywheel that is 57-1/2 inches (1460.5 mm) in diameter,
weighing-in at a
mere 1000 lb (453.59 kg).
The Hart-Parr 60 HP engine runs at 300
develops, natch, 60 HP.Since
my shop equipment is just a slight bit too lightweight to handle a
version, I've decided to scale it down to about 1/6th size. In
I've taken several liberties with the design, ending up with a bore of
inches (44.45 mm) and a stroke of 2.5 (63.5 mm) inches, giving 12.026
inches (197.07 cc) displacement.
make a rough guess that the horsepower of my semi-replica will be
around 3 to 4
horse at somewhere in the neighborhood of 700 RPM. An
interesting feature of the Hart-Parr engine is that it is hit and miss
cylinder designed to cut-out at a slightly lower RPM than the other,
giving it a
really weird cadence when it is at light loads.
The Hart-Parr has
hemispherical combustion chambers but mine will have "conical"
chambers due to the limitations of my shop. The valves are both
the cam through a single rocker.
As far as I can tell, the valves
one leaf spring which pivots between the valves. When one valve
the other is held shut more tightly.My
engine will use the same arrangement.
different from the Hart-Parr is the cam drive and governor
I've tried to find some 1:2 skew gears that are large enough for my
to sideshaft link and some 1:1 miter gears for my sideshaft to camshaft
link. They are VERY pricey so they are a no-show. I will
3/8" pitch 20-40 tooth and sprockets and roller chain to do the job.
Hart Parr engine uses a belt driven flyball governor and, since I can't
out a practical way to drive a governor in the space limitations I've
I've come-up with a governor that will be built into the cam sprocket
will be via a magnetic Hall-Effect transistor and two magnets.
will be one that has both secondary leads coming out (like a
Onan 2-banger coil). One plug wire will go to each plug and to
distributor. My distributor will simply ground the tower of the
not sure just when I'll start the actual cutting of metal on this
The raw materials (shafting, cast iron, bushings, bearings, etc.), so
adding-up to around $630.00 so this engine is going to be one of my
expensive endeavors. I still have other materials to purchase
shop charge for water-jet cutting out of the blanks for the rods,
my plan for displaying this engine (if it turns out good enough to do
with) is to re-power The 2009-1/2 Algore Edition Hybrid Green
tractor with it. Because I will ditch the "Hybrid Green" part, I
had to design the engine to rotate in the opposite direction of the
I can use the transaxle (out of a Sears Suburban garden tractor) to
it does turn out to run well enough, I'll make a replica of the
radiator and stack. I'm not so sure of using oil cooling, though.
awaiting the waterjet cutting, I started making parts.
One finished main bearing block, one
Both finished main bearing
you can see, I'm using thrust face bronze bushings for the main
The crankshaft diameter will be one inch. The blocks will be a
fit in the engine frame. The bushings will be secured in the
bearing set Loktite. I'm using lip seals to keep the oil inside
belongs. I designed these parts to be able to accommodate a
type of bearings if necessary. I figure if the mains don't
it won't be an earth-shaking project to re-machine the blocks for caged
bearings and use the same seals.
working on the governor and the farther I get into the governor, the
less I like
it. It's just about finished - leaving only the final touch-up
governor base is the flange of the sprocket on the cam end of the
chain. Slots milled in the sprocket hub are to fit the four
The weights have 40 degree cam faces that engage the inside of the
cover and ring.As
the engine speeds-up, the weights are thrown by centrifugal force
lower side of the governor cover and force it away from the
movement is supposed to force the latch rod into
position to latch
one of the exhaust valves open. A further slight increase in
supposed to latch the other exhaust valve open.
Governor at 400 RPM (800 RPM crankshaft speed.
the governor does work as shown above, I don't think it will provide
force to move the latch rod. I'm going to go ahead and finish it
if it doesn't work, I'll figure out something else.
I'm still waiting for the shop to schedule the waterjet cutting, I
look into getting a toolpost grinder so I can machine the
Wow! Even used, they aren't cheap.Since
I'm already over budget on this project, I figured I might as well
time to see if I could build my own toolpost grinder. Looking in
trusty junque, I found the motor out of a deceased vacuum
figured it would have enough torque to turn the wheel. Because
motors are series wound, unless you have a steady load on them, they
speed up. A LOT!Anyway,
I decided to try it and see how bad it could be.
Testing the grinder.
mounted the motor using a cut-up section of rectangular tubing.
was drilled for 1/4-20 bolts, the heads of which were ground so they
into the T-slots of the carriage. A mandrel was made to adapt the
the motor for mounting the wheel.Using
a variac (variable voltage transformer) to control the voltage going to
motor (and the speed), I chucked-up a piece of 1" shafting and, after
dressing the wheel, made some cuts. The wheel, off of a junked
grinder, is not going to be good enough. The balance is poor and
a relatively rough surface.
speed thing is a real problem. The wheel is rated at 3,600 RPM
motor really wants to go about 15,000 RPM. If I let it do it's
at low voltage, the grinding wheel would explode from the centrifugal
force. I may have to dig-up some electronics, make an encoder for
end shaft and use something like a triac to vary the phase angle of the
regulate the speed. An advantage of a speed regulator would be to
constant, safe speed for the wheel regardless of the depth of cut.Remember,
"Science is always working for you at Hoyt-Clagwell & Company".
that I've got eldensengines.com working reasonably well, I'm back in
I squared-up and sized the water jacket and ground the welding
is the second piece of 1/4" wall rectangular tube I've worked on.
first one, bought at a local steel supply house was burned off a larger
piece. I specified the exact length I needed, figuring they'd cut
it so it
would be at the ordered length after I got it sized. Wrong!
one end squared-up and flipped it in the mill. I made one flycut
just tink off the high spots then measured it. Drat! It was
1/8" short once it cleaned-up. Took it back to the steel supply
they gave no argument and replaced the piece. I think I'll order
everything a bit bigger next time. Live and learn.
semi-finished water jacket, ready for drilling the water inlet and
I cut the foot-long piece of 1.5" I.D X 2.5" O.D. steel tube to rough
liner cut to rough length.
I had to square one end up and clean up the O.D.
Cleaning up the
After turning the seat step, boring was started.
design calls for the O.D. of the liners called for a 2.5"
Again, I was outsmarted. The rough O.D of the pipe was actually
2.480". Okay, since I hadn't started on the headers that the
slip into, I can modify the dimensions. After cleanup, the O.D.
I had to hang the liners off of the 4-jaw chuck, I couldn't turn the
O.D. in one
operation, so after turning it as far as I could, I then cleaned-up the
end. I reversed the liner in the chuck and again painstakingly
and carefully banged it parallel to the ways. Because I did the
"painstaking" part in setting the liner in the chuck, when I finished
the O.D., there is just a noticeable look in the surface where the two
meet. I think it's because the turning of the ends is in
directions. I can measure maybe a couple of tenths of a
step at the bottom of the cylinder is 1/4" deep and it is planned to be
light press fit in the crankcase-end header. The bore diameter is
note, my boring bar is home-made using the "ignorance is bliss" school
of toolmaking. I just grabbed what was hanging out in the steel
knocked it out. Surprisingly, I can take 0.010" cuts with minimal
chatter with it hanging out there six inches.Tomorrow,
I'll finish the second liner and make plans to get the steel to the
the waterjet cutting is to be done.
back at it and now have the pistons mostly done.
took all day to do the pistons so far. All that is needed to do
them is to bore the wrist pin holes and drill the four radial oil
vent holes. The top two grooves are for 3/32" compression rings
the bottom is for a 1/8" oil ring. Initially, I will only put
compression rings in the top grooves. If blow-by is excessive, I
it down and add the second compression rings.The
pistons were turned to give 0.006" of skirt clearance. In the
area, I turned the diameter down 0.020".
day today. I got the oil return holes and wrist pin bores drilled
reamed for a press fit with the wrist pins.
pins, pin bushings and bore protectors.
wrist pins are actually 3/8" hardened steel dowel pins which are
manufactured a little oversized for press fit in 3/8" bores. I
something to protect the bores in case a wrist pin decided to wander
position so the brass junkpile yielded a short length of 3/8" O.D.
pipe which I cut into 0.085" thick "plugs" that are a press fit
in the wrist pin bores.
the piston rings came in so the first thing I did today was to check
out the ring grooves and file the end gaps. The rings are now
stored securely in the bores waiting for the rods to get done so the
piston/rod assemblies can be finished.Then, I made the Cam
bearing blocks with bushings itemporarily in place.
kinda messed-up. I forgot that I had ordered a piece of 1.500"
round leadloy bar stock, so the first thing I did was to root in the
junkpile to find something that was 1" thick and big enough to whittle
into two 1.5" diameter pieces. I found enough for one and figured
I'd have to order more steel so I made the one block (shown on the
right). The piece I had wasn't quite big enough so some edges
show but this detail is not important.THEN,
after finishing the first part, I happened to glance into the box of
materials and BEHOLD! There was the foot-long hunk of leadloy.
The second bearing block (shown on the left) was a LOT easier to
Today, I decided
to go ahead and do the cams.
Cam timing diagram.
you can see, the timing's not radical. The exhaust valve opens at
165 degrees ATDC and the exhaust valve stays open for 195 degrees.
The intake valve is open for 180 degrees with compression being
another 180 degrees. The cam shape is compensated for the 0.625" diameter
of the cam followers. The followers are small ball bearings out
of the junkbox.
Profiling the cam
A finished cam
goofed with the original drawing. The original CAD had the
camshaft being 0.625" in diameter. A subsequent revision
increased the diameter to 0.750" to add some stiffness. This
caused me to have to revise the drawing and dimensions in the shop.
It all worked-out anyhow. Tomorrow I will do the
I made the
second cam a couple of days ago and today, I started on the head.
Squaring-up and sizing the blank.
Now to size.
head is going to be complicated. The combustion chambers, as you
will see later are conical (as close as I can get to hemispherical
with my machinery and skill).
Combustion chamber side partially done.
head bolts (all thirteen of 'em) are 10-32 socket head cap screws.
The two largest holes are the bores for the exhaust valve and
guide. The intake valves are canted
down at 45 degrees.The
smaller holes just above them are 1/4" diameter holes for the spark
plugs to communicate with the combustion chamber. The plugs are
to be vertical, screwed-in from the top of the head.
for the combustion chambers is to mount the head in the rotary table,
centered on the exhaust valve bore. The mill quill will be tilted
to 45 degrees and, using a 3/4" milling cutter, the table will be
turned slowly as the head is raised. This will make the conical
shape which will be centered on the exhaust valve. The diameter
of the cone at the gasket surface will be 1.75", the size of the bore
of the engine and it will taper down to slightly above the exhaust
16 January 2012:
I got more done
today than I thought I would. The combustion chambers and the
valve bores are done.
the final combustion chamber diameter.
the combustion chamber.
Reaming the intake valve bore.
location of the combustion chambers and valve bores is critical so a
lot of time was taken checking and double checking the setups before
making any swarf.
I'll have sore arms tomorrow because
I put about a million turns on the rotary table crank. To get the
milling cutter to cut clean, I had to take a lot of 0.015" cuts.
At one turn of the table to the cut and a bunch of turns of the
crank to make a turn of the table, I think it's broken-in now.
This side of the head is nearly done.
valves are only going to be a little over 0.500" in diameter so the
engine isn't gonna be a racing champ by any means. I figure it
will breathe well enough to run pretty well.
19 January 2012:
head is almost finished. The valves must be turned down, the
guides made and seated. I still have to figure out and design the
valve leaf spring perches but there's plenty of real estate there to do
plugs in place.
Plug, from combustion chamber.
the above left photo, you can see how the spark plugs work into the
design. The spark will be back in a hole but that shouldn't
affect the running.
The exhaust ports are shown on the far side of the spark plugs.
Plug, from combustion chamber.
Intake runner to be plugged.
intake ports are connected via a 1/2" runner. In the above right
photo, you can see the drill entry end of the runner. The runner
stops at the second intake port. This runner will be plugged.
The port for the mixer is shown in the above left photo.
think the hard parts are about done. The rest is simply making
the parts and assembling them. That doesn't mean there's not a
lot left to do. I figure a couple of months may be required to
have it running.
20 January 2012:
Started on the
valves and guides today.
Valve before and after re-sizing
valves down is kinda tedious because the stem is long and limber.
I've found that taking small cuts with a dead-sharp carbide bit
helps. The original stem diameters was 0.250" but, I couldn't
leave it at that if I was going to turn the valve heads down to 0.550".
I turned the stem to (0.171") and was then going to make the
and check the fit when they were reamed to 0.1719 (11/64").
If the fit was
good (not knowing exactly what my cheap reamer would give me), then I'd
do the rest of the valves.
I got started on a guide when an "AW_SHOOT!"
Dang! The cross slide leadscrew nut went and gebusted!
was turning the O.D. of the first guide when the cross slide lead
relaxed. Turning the handle did nothing. Being an astute
individual, I surmised that something was out of order.
took it apart, I found that the nut for the leadscrew had broken.
This is another of those maddening things about Chinese
machinery. Some bean counter decided that they could save a
nickel or two by using diecast parts instead of brass or steel.
You can see the result. I've epoxied the nut back together
and am going to use a slightly longer mounting screw that gets into the
thread in the body of the nut. I hope it lasts until the
replacement part arrives.
It may be a cheap lathe but there's
nothing cheap about replacement parts. That two-ounce nut runs
about $12 with about $12 shipping! If I had a left-hand 1/4-20
tap (close to the metric size of the original screw and nut, I think
I'd get some precision 1/4-20 all thread and make one outta brass.
I'll see tomorrow if the fix will work at all. If not, I'll be
taking a vacation from the project until I get the part.
21 January 2012:
"glue job" didn't work so I fell back to Plan B. Plan B consists
of re-tapping the M6-20 thread to 1/4-20 (a little bigger) as far as I
could go without interfering with the leadscrew. That gave me
about 1/4" more thread to work with. Then, I cut a brass 1/4-20
flat head screw until it ----almost---- touched the leadscrew thread.
It's now back together and, so far, is working.
The valve guides are made and have been pressed into the head.
Head with valve guides installed.
guides were reamed to 0.1719" and ended up a little oversize but, after
pressing the guides into the head, the fit was very nice.
started on the other three valves. The head diameter and the
head thickness are to size. Tomorrow, I will turn the stems and
cut them to rough length. I will hold off the final length and
the retainer grooves until I've got the cam and rockers done.
Then I can get the fit optomized.
22 January 2012:
The valves are
now resized and lapped to the head.
the valve stem.
The head with valves installed.
another fiddly job done. Tomorrow, I'll call the machine shop
once more to see if the steel parts are cut. If not, I can work
on the rocker bushing blanks and design the valve spring arrangement.
23 January 2012:
Today, I got a
couple of the little things done along with making a better
homebrew toolpost grinder.
end of intake passage.
Cam stand mounting pads.
made a steel plug for the drill access point of the intake passage.
This hole was drilled through the head and intersects both intake
valve ports. There is a hole drilled from the outside center of
the head perpendicular to the passage that intersects it. The
mixer will be mounted to this passage.
Another little job was
making the mounting pads which the cam stands are to be welded.
They are marked for positioning the stands before welding them.
24 January 2012:
I've made a new
new toolpost grinder doing a test cut.
The finished test cut.
a decent grinding wheel and motor, I think it will suffice. I
need to be careful how much I take off per pass because I've already
found that the wheel wears fastest at the leading edge (duh!). I
suppose I'll need to get to within a thousandth or so of the finished
diameter then dress the wheel flat before taking off the final amount.
worked out well because the shop called and said they'd be doing the
cutting this afternoon. After I got the full-price quote for all
of the cut pieces, I decided to only do those that I have no way of
doing in my shop. This engine is getting to be very pricey!The
flywheel was to be cut out but, because of the amount of
cutting machine time, I'll have to do it with my mill. Now THAT's
gonna take some time but the upside of it is that I'll have to purchase
some new carbide cutters and they should be good for much more work
after the flywheel's completed.
crankshaft will be blanked out as well as the rocker arms and the
connecting rods. They are the most complicated shapes that I have
to cut and are cut from the thickest steel. The crankshaft is cut
from 1.250" thick steel, the rods are cut from 0.625" steel and the
rocker arms are from 0.375" steel. The 0.250 parts include the
two cam towers which are complex shapes but since the metal's
relatively thin, I can cut them out on the bandsaw. The rest of
the parts are simple rectangles and squares with some large diameter
25 January 2012:
afternoon I picked up the parts from the shop that does the CNC
waterjet cutting. I'm going to give the shop a plug here because
they are so nice to work with. The
Machine and Laser
1010 Aberdeen Loop
Panama City, Florida 32405
(850) 248-4000 [email protected]
The owner is
David Dominik and the guy who did the cutting for me is Sam Bouldin.
does a lot of CNC machining and their water jet cutter can make
something as big as a bull gear for a Hart-Parr 30-60, or even larger.
Okay, now that I've got the shameless plug out of the way, we can get
back to our exciting adventure into metal whittling.
The crankshaft blank.
Centering the crankshaft in the 4-jaw chuck.
made the CAD files for each part, adding 0.060" to all dimensions to
account for the widening of the kerf at the bottom of the cut.
end of the crankshaft blank was carefully center punched then it was
mounted in the 4-jaw chuck and centered at the chuck end with a dial
indicator. After bumping the crankshaft until the center punch
mark was exactly centered on the live center, the center was removed
and the drill chuck was put in the tailstock. Using a drill
center, a center hole was drilled in the end of the crankshaft.
The chuck was removed and the live center was snugged-up.
the "clunkety-clunk" part.
Taking the finishing cuts.
first, I thought I'd need to grind the main bearing journals but
decided to turn them to close to finish size. The turning went so
smoothly, I just finished the journals by taking very light cuts until
the main bearings would just -barely- start onto the shaft. Using
400 grit emery paper and mineral spirits, the journals were carefully
taken down to size. In doing this step, the surface finish was
improved. The mains now have about 0.0005" clearance and I figure
that, with running, they will end-up having about 0.001" oil clearance.
Mains finished with the main bearing blocks in place.
you can see the crankshaft with the main bearing blocks in place.
The bronze bushings are a light press fit in the steel blocks
which will fit snugly into bores in the crankcase sides. I have
left the distance between the thrust surfaces on either end of the
crankshaft at a larger distance than the drawing shows. When
doing the final assembly of the engine, I can remove enough steel from
these surfaces to set the end play.
Tomorrow, I will make the offset arms and, maybe start on the throws.
26 January 2012:
was slow today. To make the offset arms for machining the crank
throws, I had to cut-up a really nasty hunk of 3/4" steel that had been
torched off of something.
offset arms with the driving pin.
on the crankshaft.
And in the lathe.
that I have the crankshaft with the offsets in the lathe, I'm trying to
figure out how to turn the throws. In the right-hand photo, I've
got a big carbide bit in the tool holder. If I end-up using it,
I'll have to mill about 1/4" off of the bottom of the bit to get it
centered vertically. I may try some oddball configurations of the
grinder also. I know it can be done with what I've got, it's just
got to come to me.
27 January 2012:It
took all day but I got one of the throws turned. Doing the rods
is chatter city so I have to take small cuts and LOTS of 'em.
myself a little room for the compound.
Turning a rod journal.
thinking on it for a while, the first thing I had to do was to remove a
little of the extra metal from the radiuses of the main bearing
journals. This gives me enough room to move the compound in
enough to work on the rod journals.
To get the rod journal from
square to round, I used an old brazed carbide bit, taking small cuts
until the journal was almost round. Then I switched to a
I had a 1/2" HSS tool bit that was long enough to reach
the rod journal without the compound running into any of the twirling
hardware. Since my tool holder is set-up for 3/8" tools, I
modified the bit by grinding the cutting edge lower by 1/8"so it
was on center. I then ground it to about 0.100" wide and gave it
a round cutting end. This worked reasonably well as long as I
only took 0.010" cuts. Any more than that and it would chatter.
reversed for the second rod journal.
This shows the offset.
turned the journal to size (1.000" X 0.750" wide) then used 400 grit
emery paper to take off 0.0005" and smooth-up the bearing surface.
After the rods are done, I'll use lapping compound to seat the
rod bearings. Since the mains are non-adjustable bushings, I'm
not able to lap them.
28 January 2012:
crankshaft is done. On this throw, I tried something I've tried
before to minimize the chatter.
the second throw.
The finished crankshaft.
I did to fix the chatter problem was to wrap the crankshaft with a
length of lead solder. Since lead is a very highly dampened
metal, it absorbs the vibrations. The fact that it added mass to
the workpiece only helped.
I put it up in the mill and cut the
1/4" keyways. At this time, there's nothing planned for the power
takeoff end of the crankshaft opposite the flywheel but I cut a keyway
there, too. No telling just what kind of work I might put it to
29 January 2012:
Except for the
bronze bushings (which I forgot to order earlier), the rods are about
rod blanks and drawing.
Boring the big ends.
rods weren't really complicated to do and the pickiest part of the job
will be cutting the caps off with the bushings in place and milling the
sawed surfaces flat and to dimension. A shim pack will be made-up
to compensate for the saw kerf plus cleanup. After that is done,
the rods will again be put in the mill and the big end bearing will be
bored for a tight fit to the crankshaft. The finishing touch will be
using "Timesaver" lapping compound to fit the rod bearings to the
I've also drilled and tapped the 1/4-28 rod bolt
holes before cutting the caps off. This is to ensure the caps
will register with the rods when assembled. All I had to remember
was to drill the 1/4" clearance hole only slightly past the pre-marked
parting line. The tap drill was run the rest of the way through
the rods. I've also drilled across a the bolts for a 0.050"
safety wire to make sure that the bolts don't work loose.
wrist pin bushings will be pressed-in last then the oil holes will be
drilled. A little metal will need to be removed from the pin
bushings to get a good fit.
You will note in the center photo
above, that I've lightly pressed a 0.500" dowel pin through both small
ends. This ensures that the rods will stay in registration during
the boring of the big ends.
30 January 2012:
arms/cam followers are coming along.
The rocker arms, nearly ready to be assembled.
most tedious part of the rocker arms was the slots for the cam follower
ball bearings to fit into. The slots are 0.200" wide, 0.750 long
and are 0.400" deep. Using a carbide 1/8" milling cutter, I had
to make a whole mess of passes to get the slots made. Finishing
the rockers should be pretty easy, assembly only.
31 January 2012:
follower/rocker arms are done.
view of the follower/rockers is looking toward the head. The
cams run on the rollers. The tappets for the exhaust valves are
opposite the rollers and the tappets for the intake valves are on
the ends below the shaft. The long tails are for the
governor latch to work against.
2 February 2012:In
response to a couple of requests, I'm belatedly posting a couple of
scans of Hart-Parr documentation to try to explain the valve
arrangement of the engine.
Cutaway views of the Hart-Parr 30-60 engine.
the engine is overhead cam. The cam works directly on the single
rocker arm for each cylinder. On the high part of the cam
profile, the exhaust valve is pushed open. The rocker arm has a
relatively strong torsional "hairpin" spring that tries to force the
rocker to the intake profile of the cam. The intake valve spring
is weaker than the hairpin spring so, when the cam profile goes to the
intake portion, the hairspring overpowers the intake valve spring to
allow the valve to open.
To complicate matters, in the H-P
engine, both valve springs are flat leaf springs with a third long
spring, pivoted in the middle that operates against both valves.
This extra spring serves to increase the holding force of one valve
when the other is open.
It's sort of complicated sounding but
works on the tractors. Now, whether or not I go with the actual
three leaf spring plus hairpin spring or not is still in
question. There's plenty of room on the head for any number of
arrangements and, if at all possible, I'd like to go with the H-P
This seems like a pretty good breaking point so i'm
probably going to take a few days off the project to catch-up on some
other stuff. Stay tuned.
7 February 2012:
In the last
few days, I've gotten the rods done and pistons hung as well as a good
start on the cam stands.
marked for cutting.
Bushing being marked for cutting.
Bushing and rod cut.
Measuring for shims.
Checking diameter after shimming.
Boring bearing round and to size.
and journal after lapping.
Wrist pin bushings and
oil holes in rods.
Pistons hung on rods.
procedure I use for cutting the rods and bearings and fitting them
consists of measuring to the center of the big end bore then scribing
the cut line. The bearing is marked using a center square and is
cut in two then witness marked to the rod. The cap and rod joint
and the bearing joint are filed more or less flat. A little more
is taken from the rod and cap in order to assure the bearing will be
crushed in the rod when the bolts are tight.
The rod and bearing
are assembled and the diameter is measured perpendicular to the cap/rod
joint. This determines the thickness needed for the shim pack in
order to make the bearing more or less round and slightly smaller than
the crankpin. The rod is then assembled with the bearing and
shims and the dimension is checked to make sure it's close. At
this point, the big end of the rod is carefully centered in the mill
and the bearing is bored about 0.0005" smaller than the journal.
rod, shims and bearing are mounted to the rod with the bolts only tight
enough to allow the rod to turn on the crank. The rod/crank are
mounted in the lathe and lapping compound is applied. Rotating
the crankshaft with the lathe while holding onto the rod and
occasionally tightening the bolts removes just enough metal to assure
that the rod bearing and crankshaft are a good fit. After
disassembling, cleaning off the lapping compound and reassembling, the
fit is checked.
The wrist pin bushings are pressed into the
little ends of the rods and are reamed to fit the 0.375" wrist pins.
Then the pistons are assembled to the rods by pressing the pins
through the skirts. With the rings installed, the piston/rod assemblies
are done. Note that I'm only using two rings (one compression and
one oil control). If there are blowby problems, I can always
install a second compression ring in the empty groove.
out cam stands.
Partially finished cam
stands were cut to approximate shape from 1/4" steel plate using the
bandsaw. The rocker shaft and cam bearing bores were done.
Left to do is drilling the governor latch rod holes then pressing
the bearing blocks into the stands then welding the stands to the
8 February 2012:
train is beginning to come together.
Cam, rocker arms, latch shaft and speed adjuster in place to
went fine until I got out the wire welder to attach the camstands to
the bases. DRAT! The last time I used the welder, I forgot
and left the tank turned on. Although it's not empty, I sure
un-used about three fourths of it! Then, when I went to do the
welds, the welder wouldn't feed wire. I took a look and found out
that one of the flanges on the 10 lb. reel of wire I just got had
broken loose and the wire was starting to fall off. I rigged a
temporary reel on the lathe and spooled all the wire off of the broken
reel, fixed the reel then re-spooled the wire back. That took
about two hours. Some not-so polite words were spoken during that
After getting the welding done, I pre-assembled the parts
to check the fit. I will have to make a few changes because I've
decided to run the engine in the opposite direction from the original.
This is because I've already got the alternator mounted on the
tractor and it needs to be turning clockwise facing it. One of
the changes is to remove some of the cam hubs so I can put them on the
shaft the other way around. I'll use small setscrews on the
abbreviated hubs to get the timing set then drill and ream
for taper pins.
was one of those "fiddly" days. Getting the valve springs figured
out so they worked was a challenge and I'm not sure I have them to the
point where they'll operate correctly.
springs and pivot.
Spring to be modified for rockers.
Rocker return spring.
spring in position.
leaf springs are made from a piece of steel strapping. I
think they're going to be springy enough to do the job. They are
a point that makes the exhaust side stronger than the intake side.
With both valves closed, the springs just have enough force to
valves shut. Because of the pivot, when the exhaust valves are
open, the intake valve springs are stronger and the same goes for when
the intake valves are open. This
also applies increased closing force to the intake valves when
thecylinders are latched-up and coasting.
Intake valve open.
the lack of a better term, I'll call the wire springs the "override"
springs. Their purpose is to supply enough force to overcome the
intake valve spring force when the cam is at it's lowest point
(intake). Without these springs, a much more complicated cam and
a second follower would be necessary in order for both valves to
The first override spring I've made is made from
the pop-up spring taken from a dead lawn sprinkler head. After
straightening, it was bent so it hooks under the exhaust end extension
of the rocker arm, bends around the rocker at the bearing then is
anchored using a method I haven't exactly gotten worked out.
Although the spring works as desired, I'm thinking of modifying
it so it doesn't look quite so "lumpy". Also, I'm using a scribe
as a temporary holding device and am considering simply using a piece
of large wire that lays against the exhaust valve guides, held in place
by the hooked ends of the springs.
11 February 2012:
I think I've
got the override springs worked out.
Valve arrangement about done.
re-did the override springs and added a bar to hold the head ends of
them. I think this will work but I'm going to have to modify the
holdback bar where the red mark is. This is an interference point
with one of the head bolts. What Ipll probably do is to cut the
bar and weld in a square piece of 1/4" stock, drilled for the head
bolt. This will actually be an advantage as it will keep the bar
from moving around.
Next, I'm going to do the cylinder block, consisting of the two
headers, the jacket and the liners.
12 February 2012:
The header blanks are sized and the crankcase end header is well along.
Cylinder bores for crankcase header.
How cylinder liners fit into
my mill isn't big enough, I have problems squaring-up pieces that are
over about 5". I used the flycutter to do two edges of each piece
but I could not do the other two edges with the
flycutter because I couldn't get the knee down far enough. I did
the other two edges of the head-end header in the mill vise using an
end mill but ran out
of travel as you can see in the photo. That necessitated flipping
the piece over and sneaking-up on the surface from doing the previous
end of it. The header ended-up being within +/- 0.004" of true
The crankcase end header had to have it's other two edges squared-up
after clamping it to the table.
I then removed the mill vise and clamped the crankcase-end header
blank to the table, shimmed-up 1/4" from the table. After
squaring it up with the table, I located and spot drilled the through
bolt holes. There are other holes in the edge of the piece that
I'll spot and drill later.
I used a 1-3/4" hole saw to
start the cylinder liner holes then used the boring head to bore
them out to 2.250" diameter to accept the liners. Next, I'll put
the header in the drill press and finish the already spotted eight
clearance holes and the six edge holes. After that, I'll do the
15 February 2012:
block is now a cylinder block, not just parts.
Block parts laid together.
Block welded, cleanup progressing.
my usual welding skills, I'm milling, filing and generally hiding the
welding boogers. I still have some cleanup to do then I have to
tap the headbolt holes (10-32) and mill the deck flat. I probably
won't do any milling on the other end header unless it's warped in such
a way as to make the alignment poor.
And, yes. After welding, the liners still fit, although a bit
tighter, which is good.
17 February 2012:
I'm getting tired of fighting surface rust on all the unpainted steel
and iron in my engines, I'm changing my policy and painting the
block/crankcase and maybe the head. Of course, I'll use the
official Hoyt-Clagwell company color, Rustoleum dark Hunter Green.
Today, I got the side plates finished and the top and back plates sized.
plates stacked together and marked.
Side plates and
bearing clamps finished.
goofed a little in finishing the bores for the main bearing blocks.
They are a slip fit. I intended them to be almost a
press fit. I don't think that will be a problem though. If
to, I can always use thread locking Loctite to keep them from moving
around in the 0.0005" clearance. The clamping pieces are made of
0.625" bar stock with a step to hold the bearing blocks against the
All that's left to do is to drill and tap the holes
in the side, top, bottom and back plates, install the crankshaft and
set the end clearance and install the liners, pistons, head and work
out the timing chain tensioner, the ignition and the mixer. After
that, I can tackle the flywheel which promises to be challenging.
The end is in sight.
19 February 2012:I've got the
crankcase and base far enough along to be able to "stick' them together
to check alignment and fit.
of bottom plate showing milled mounting surfaces and nut/shims.
of bottom plate, flycut flat.
bottom plate, which is 1/2" thick, was sheared from stock by the outfit
I bought it from. Their shear must have either been out of
adjustment or very, very dull. The piece was more "chomped" off
than sheared. Aside from having a couple of really nasty cut
edges, the plate was bent in the process. I spent a while with
the press, trying to straighten it and got about half of the bend out
of it but ended up putting the plate in the mill and milling four
"pads" of equal depth. As you can see, the upper left pad just
I then used 1/2-13 nuts to make equal height
shims to mount the engine. Flipping the plate over and using the
shims to level it on the mill bed, it was then flycut flat for mounting
of the engine frame parts.
Partial assembly to check fits.
will have to mill the bottom surface edges of the cylinder block due to
warpage from welding. The amount is minimal, probably less than
0.015" will clean it up.
Note that I've only drilled and tapped
one hole in the side and end plates. This is so I can bolt it
together to check fit. The remaining clearance holes are drilled
to the tap drill size and, after assembling the parts and getting the
alignment correct, I will drill through the tap size clearance holes
with a tap drill. After drilling the tap holes, the clearance
holes will be redrilled to clearance size. This will assure
everything stays aligned. I'm not planning on welding this one
together unless I notice that the parts are "working" when the engine
has been run. In that case, I will have to disassemble the
engine, weld the frame together then strip and re-paint.
Note that the cylinder block is the color the rest of the major parts
of the engine will be.
24 February 2012:
After a pause,
I'm back at it. The rest of the frame hole threading is done and
a starting crank has been made.
Starting crank in place.
Motoring to take
stiffness out of main bearings.
main bearings are a really close fit so I decided to motor the
crankshaft for a few hours to insure against galling the journals when
the engine is first run. If the stiffness persists, I can always
mix a little extra-fine TimeSaver brand lapping compound in oil and
mineral spirits and apply the mixture to the oil holes. Since
TimeSaver lapping compound does not embed in the bearings or shaft and
because it grinds itself finer and finer as it works, it's good for
bearing fitting. Per the instructions, it doesn't even need to be
cleaned out of the bearing after lapping because oil flow will remove
what's left of it.
25 February 2012:
The head gasket
is made, the head is on and the pistons are in.
Motoring with head and pistons installed.
Relief for bore clearance on rods.
was interference between the cylinders and the rods. I had the
sneaking suspicion that this would be the case but all it took was
milling about 0.070" off the rods. I made the oil scoops and they
Everything seems to fit pretty well and I intend to
motor it for a couple of hours to start seating the rings and bearings.
Once I get the top-end assembled and the timing chain and
tensioner on and timed, I can see if the valves are sealing well.
26 February 2012:
starting to look like an engine!
with head, cam, etc. working.
see if oil is moving. It is!
took a bit of wrestling to get the cam, rockers, timing chain,
tensioner, etc. done. The cam timing's set to about optimum
with the exhaust opening a little before BDC and the "overlap" (where
the exhaust closes and intake opens). The dang thing's looking
like an engine now.
The timing chain tension idler is made of
three pieces of some kind of self-lubricating nylon made into a flanged
roller. It runs on a brass shaft that has the mounting bolt
drilled off-center to provide for adjustment. Since it doesn't
have a flywheel, I can't put the plugs in because if I stick my finger
in a plug hole, the compression will cause the drive belt to slip.
In any case, it's throwing a lot of oil out the plug holes and
exhaust ports so I know the cylinders are oiling. I ran it with
what I think is the proper amount of oil in the crankcase and it's
getting everything nicely sloppy when motoring at about 550 RPM.
governor action is almost non-existent at 550 RPM. It just slowly
comes out with almost no force. I'm hoping it will respond better
when the engine's running at what I think will be a good speed, about
I'll be taking about a week off from the project and will restart
sometime after the first week of March.
6 March 2012:
After a pause, I've
gotten back to the project. Today, I made the "distributor".
ignition is "distributed" using a 2-cylinder coil and grounding the
plug that is not to fire. It sounds kinda odd but I did the same
thing with the Edwards ignition and it works fine.
There is a
Hall-Effect transistor mounted on the phenolic piece with the handle.
This is the "fixed' portion of the system, which is rotatable
through about 25 degrees of crankshaft rotation to allow for timing
adjustments. The white circular object is the rotor, which is
made out of a piece of copper-clad 1/16" thick fiberglass printed
circuit material. The rotor has two magnets glued to it,
separated by 90 degrees which pass the Hall Effect transistor to
trigger the coil. The rotor also has copper foil to ground the
"unfiring" plug. You can see the copper cladding through the
The coil/plug leads are located on the "fixed" part, one at six o'clock
and the other at 9 o'clock. The rotor turns
counterclockwise as seen. One
end of the coil secondary goes to the 9 o'clock lug and to the number
one spark plug. The other secondary lead the coil goes to the 6
o'clock lug and on to the number two spark plug. When #1 fires,
#2 is grounded through the screw and the foil on the rotor. The
#1 screw is located over the insulated part of the rotor. The
opposite occurs when the rotor has turned to the #2 position.
7 March 2012:I
set the ignition in time and discovered that I had to move the #2
cylinder magnet in order to have both cylinders fire at the same point
in their cycles.
Rotor with adjustable #2 magnet.
was done by gluing the magnets to screws. The #1 magnet was fixed
in place. I filed a slot for the #2 magnet so I could change the
angle in relation to the #1 magnet. This resulted in both
cylinders firing within a degree or two of each other.
Governor latch follower and rod in place.
next order of business was to make the governor latch follower.
In the photo above, you can see the roller (a small ball
bearing), it's mount, the guide rod and the latch rod (the long one).
the adjustment nut on the right end of the latch rod is a spring which
works against the governor to set the engine latch-out speed.
Turning the screw toward the governor raises the speed and
turning it away lowers the speed.
I may have to re-visit the
governor when I get the engine running because I don't think it will
make enough force at the speeds I intend to run the engine. If
need be, I will disassemble the whole camshaft and governor assembly
and make some additional weight plates to attach to the present weights.
12 March 2012:
much has been done for the last week or so. I came down with the
Redneck Riviera Crud and haven't been spending a lot of time in the
shop. About all I've gotten done since the last entry is to make
the governor latches.
Governor rocker latches in place.
the photo above, the roller on the left of the cross shaft contacts the
governor sleeve. When the engine speeds-up the sleeve will move
to the right as seen in the photo. That motion will cause first,
the left-hand latch to ride over the end of the rocker of the #1
cylinder when the exhaust valve is open. The latch on the right
is adjusted to hook the rocker of #2 slightly later so, if the engine
speed is great enough, both valves will be latched open. The
setup for this test will have to be changed once the governor is
modified and everything is re-assembled.
I hope to be able to give enough time to the engine within the
next week or so. Thanks for your patience!
14 March 2012:
felt pretty good today so went out to the shop and actually got
something done. I'm pretty well along with the added weights for
shaft slots in governor hub.
One original weight in place.
One extra weight in place.
final plan was to add the weight to the other side of the
sprocket/governor instead of trying to put the extra weights on the
side with the originals. I figured that I could get more weight
on the other side. More is better, eh? AND, if I need even
more weight, I can replace the present extra weights without
disassembling the cams, distributor, etc.
weight on left. Added weight on right.
Two of four
extra weights added.
weight to the governor will do two things. First, it will allow
it to be effective at lower speeds and it will increase the force of
20 March 2012:
After a "pause",
I'm starting back with it. The governor's reassembled and the
camshaft and all are re-assembled.
All back together.
that I've got it back together, I find that we have a problem with the
latching arrangement. Since I've never been able to get up close
and personal with a real 30-60, I have to guess what some of the
mechanisms look like. In operation (at present) all's well until
after the first cylinder (on the left) latches and the second cylinder
(on the right) latches. Then, since both exhaust valves will
never be open at the same time, the cam will never be able to relieve
the pressure of both of the rockers against the latches at the same
time. This will keep thge latch rod from moving to the left and
the engine will stay latched-up.
I think I've got a fix for this
condition and that's to put a swinging element on the #1 latch so, when
the engine speed reduces from both cylinders being latched-out, the
swing element will keep the pressure of engagement from the #1 rocker
from keeping the latch from moving away. As soon as the second
(right-hand cylinder) unlatches, the left-hand cylinder latch is free
to move when its' cam is in the exhaust position. Easier to do
than explain, I'll photograph my "fix" as I make it.
Just for the heck of it, I may motor the engine to see if I may be
wrong and the swinging element isn't needed.
21 March 2012:
was a bust! I belted-up the engine to check out the governor
operation and found the design to be a failure because of the
orientation of the weights and cam surfaces. There is just too
much binding in the whole system. Because of that, I've scrapped
that idea and will design a flyball governor that is belt driven from
the power take-off side of the crankshaft. I plan to run it at
about twice crankshaft speed (as opposed to half crankshaft speed per
the other design).
Sometimes things work out and sometimes you need to just back-off and
start over. This is one case. A minor setback.
also been thinking of the procedure for machining the flywheel and have
decided to go ahead and get the spokes cut using water jet. I can
do the turning all right but the spokes would require a LOT of machine
time and many setups - that process is just too prone to a major
24 March 2012:
the governor to a standard flyball type.
The new governor.
that I haven't removed any hidden lines. This makes the drawing a
little harder to read but I think you can figure out what I've got in
The governor will be belt driven from the side ooopsite
the flywheel using a 1/4" round leather belt. Both positions of
the governor are shown.
With the engine at rest, the weights are
against the shaft and the shafts and linkage are as shown. When
the engine speeds-up, the weights move out. Since the lower ends
of the links is vertically fixed, the top end of the links moves down.
The shaft goes through the drive-shaft and to the "cup" and
thrust bearing. When the shaft moves down, the linkage is
pulled down, rotating the latch
shaft clockwise and causes the latches to
engage the rocker arms, holding the exhaust valves open.
Speed is adjusted by turning the vertical bolt that changes the spring
pressure holding the shaft up.
25 March 2012:I've got a good
start on the new governor.
The mainshaft and pushrod.
thinking about it, I was a bit reluctant to drill and ream a 1/4" hole
through the mainshaft. Without perfect drill bit geometry,
there's no telling where the hole will end-up after going over 5
inches. Taking a peek in my pipe bin, I found a piece of schedule
80 (thick wall) 1/8 pipe. The I.D. was too small but it could
easily be reamed out. The O.D. was also too small by about 0.100"
but that could be remedied with a couple of bushings.
After reaming out the pipe, the fit to the 1/4" pushrod was too snug so
I lapped it to fit. And a nice fit it is!
The governor so far.
frame for the governor is made of 1/4" steel plate with a couple of
3/8" hunks for the bearing mounts. At the left (in the photo
above)| you can see the speed adjust bolt. This will change the
spring pressure working against the pushrod to vary the engine speed.
bearings are on order as well as a length of 1/4" round leather belting
and some clips. They should be here on Tuesday, just in time.
doesn't look like much has been done but I got the lower spring mount,
the upper spring mount/thrust bearing, the pulleys and the mounting
holes finished. All that's left to do is the weights (2 each),
the weight arms (8 each, waiting for the metal) with bushings, the
linkage to the latch shaft (waiting for metal), the bearings (2 each,
waiting), the drive belt (waiting) and some fiddly bits. Ever
27 March 2012:
Well, the parts
came yesterday (a day early) after I'd posted progress to date.
Today, I made significant progress.
Making the weight arms.
Finished weight arms.
order for the weight arms and the weights to line-up properly, the 1/8"
thick arms had to be milled to 1/16" at one end so they could overlap.
I've decided to not bother with making the 1/4" bushings for the
weight arms and simply drilled the arms for clearance of 8-32 machine
Governor and linkaga minus weights and weight arms.
also got the governor bearings installed and assembled the governor
minus the weights and weight arms. There is a 1/2" diameter
barstock link to align the arms from the latch shaft and the governor.
I applied something I saw on my '50 Chevrolet front suspension.
On the knuckles and upper and lower arms, GM for years simply
threaded the arms and made nuts that fit into the "A" frames. As
long as you kept them greased, they did fine. In the right-hand
photo, on the latch arm end of the link, I threaded the link and
the arm 8-32 then
tightened a brass screw into the arm. The link was then screwed
onto the screw, leaving it about a quarter turn loose. The
governor arm was then screwed tightly to the link. The motion is
Tomorrow, I'll make the weights and assemble the rest of the governor.
28 March 2012:
only thing left to do is to work out the valve latches. I'll take
a couple of days to think this one out while doing some "honeydo"
with engine at rest.
Governor with engine at 450 RPM.
visit to my friendly local hardware store could be in order. In
all my boxes of springs, I can find none that allow the governor to
operate at somewhere around 500-600 RPM. I have the one shown
that maxes out the governor at somewhere over 450 RPM and another one
that just gets the governor off rest at about 600 RPM. This
governor will be plenty powerful to operate the latches so I'm pleased
The other alternative is to re-make the pulley on the
governor so it runs a little slower. It's presently running at
about 1-1/2 times crankshaft speed. Within the space I've got, I
can most likely get the ratio down to about 1-1/4 times crank
speed. This would probably make the spring that's on it now work
all right at about 500-550 RPM. As I say, I've gotta think on it.
31 March 2012:
me some new springs and found a pair that will work. One of them
is on the rotating part of the governor below the top swivel (you can see it in the left-hand photo below) and
the other one is in the normal place. The top spring compensates
for the weight of the assembly at rest and the bottom spring adjusts
At #1 (farthest) latchout speed.
At #2 (nearest) latchout speed.
dunno if you can see how the latches operate in the photos. The
latch for #1 cylinder (farthest away in photos) has a hinged plate on
it. This is to allow the governor to unlatch the #2 cylinder
(nearest in photos). Because, when both latches are engaged, and
since there's always pressure on one or the other of them, the friction
between the latch tips and the rockers is enough to keep either of them
from moving toward the unlatched position. The little plate
allows the governor shaft to rotate enough to release the #2 latch when
the speed is reduced. It took a bit of fiddling to get it to work
right but I think it'll do until I get the engine running and am down
to the "fiddly bits" of tweaking it to run well.
it, I've noticed that it's throwing a lot of oil out of the ports and
spark plug holes. I hope this isn't a hint that this might be a
smoky beast. It seems to me that, when the flywheel is done and I
can run it with the plugs in, compression should tend to shove the oil
back toward the crankcase.
1 April 2012:
was one of those "two steps forward, one step back" days. The
step back was when I was motoring the engine while working on the mixer
and exhaust, when I heard a snap. I took a look and found that
half of one of the "hairpin" springs had broken off. Since
the intake valve was still opening all right, I decided to leave it
that way and, if it continued to work all right, I'd just cut off one
end of the other spring. Shortly afterward, though, while
motoring, I heard another snap. The other end of the spring had
broken off and the intake valve wasn't opening. Gotta re-think
At least the exhaust stubs are done and I've got a start on the mixer.
Beginnings of the mixer.
exhaust stacks are some 3/4" EMT tubing I had around. The mixer,
since it will be located below the gas tank, will have a float chamber.
The aluminum float chamber is part of a scrapped "aw-shoot"
piston. I plan to make the float out of 0.0015" thick brass shim
stock. The brass tube above the float chamber will go through the
float and will guide the float by fitting over the stud mounted on the
drain plug. On the upper part of the tube, I'll use a
viton-tipped float valve off of something.
I'm going to bore out
the throat of the mixer to somewhere over 0.500" which is the size of
the port. I will then press in an insert with an I.D. of about
3/8" to act as a venturi. Necessarily, the fuel mixture needle
valve will be somewhat hard to access because of the shallow height of
the cylinder block. If it poses a problem, I'll make a flexible
shaft to bring the adjustment wheel to an easier access point.
to figure out is how to mount the float chamber to the throat and get
the fuel to the jet. It'll probably include drilling vertically
down the 1/4" thickness of the float chamber wall then intersecting
this hole with another horizontal hole close to the bottom of the float
bowl. At about the level of the fuel or slightly higher, another
intersecting hole will be drilled that will go to the jet. The
top of the vertical passage will be tapped and a screw will be
bottomed-out in short threads to seal it. I think I can manage
mounting the float chamber by using the horizontal holes. We'll
Another one of those good and bad days. I thought I
was finished with the mixer but the float valve doesn't want to work.
Parts of the mixer.
the left-hand photo, you can see at the bottom of the float, the screw
that connects it to the mixer throat. Right above that is a hole
that goes through the float chamber. This hole intersects with a
vertical passage from the top of the chamber and through the venturi
hole. The outside of the lower hole through the chamber is sealed
by the gasket that goes between the float chamber and the mixer throat.
The top of the vertical passage is partially tapped 4-40 and a
small setscrew is screwed tight into the incomplete threads to seal it.
haven't necked down the throat but have used the horizontal lead from
the float chamber fuel passage to make a sort-of venturi. This is
a 1/4" thick steel bar, drilled 0.150" at a right angle, roughly
centered in the mixer throat. The venturi is drilled and tapped
10-32 for the needle valve to the perpendicular hole, then 0.040" from
the other side of the perpendicular hole to the fuel passage. The
needle valve seats into the 0.040" hole.
I think I'm going to
have to make a new float that floats better. This one does float
but won't push the valve closed enough to not leak.
new torsion springs to replace the "hairpin" springs that have failed.
I took a guess at what torque the springs need to produce and
will see, probably tomorrow. I also ordered a governor spring
that has about twice the compression pressure as the ones I've tried
before. I'll remove the spring I put between the top weight arm
and the shaft because I think that is contributing to a sort of
7 April 2012:
The new float
is done using as raw material, cork lab stoppers.
material for float.
Grinding to size.
Drilling for needle/guide.
thinkin' on it for a while, I decided to get some cork and make the
float out of it. The material that seems to be right is
simply........corks. The problem of how to accurately and neatly
shape the cork into a float was done by using the Dremel in the lathe
as a little-bitty toolpost grinder. It was kind of messy but got
the job done. Before cutting the float off of the workpiece, a
hole was drilled for a snug fit of the needle/guide.
needle was made from a piece of small drill rod. The point was
made with the Dremel toolpost grinder. After finishing the float
and checking for fit, I dug out some clear epoxy I got at a swap meet
and mixed-up enough to test against gasoline. A piece of PC board
material was coated with the epoxy and, after using the heat gun to
accelarate the hardening process, it was dipped into gasoline.
After an hour there was no softening of the epoxy so I deemed it
fit for the float. It's probably going to take 24 hours or so for
it to cure enough for me to assemble the mixer and test the float valve.
for "hairpin" springs.
New springs in place.
thing I'd ordered was a couple of hefty torsion springs to replace the
home-made "hairpin" springs. These are made of 0.125" diameter
music wire. After trimminmg the ends of the springs, the rocker
arm shaft had to be disassembled to install them. I like the way
they work and, since they are barely stressed at all, they should work
The flywheel blank goes to the machine shop for the
waterjet cutting on Monday. The wheel will be in the shop for up
to a week so I'll work on the mounting, cooling, etc. The plan is
to remove the McVickerish engine from the 2009-1/2 Algore Edition
Hybrid Hoyt-Clagwell and replace it with the 30-60. The base
plate of the new engine has the mounting holes drilled for the chassis
of the tractor but, since the plate is shorter than the plate on the
McVickerish, I'll have to drill a couple of new holes. The
alternator on the tractor will drive off of the flywheel, the same as
with the McVickerish.
(upside down) with choke closed.
(upside down) with choke open.
Mixer in place for test fit.
epoxy hardened nicely despite it's age. The test strip soaked in
gasoline overnight and was not affected so I think we're ready to go.
I assembled the mixer and made a choke for it. I haven't
tried hooking up the fuel line to check operation of the float because
I want to allow a few days for the epoxy to fully cure.
In the next part, I will finish the engine, get it mounted and see if
it will run.