MAY 2010 Crank successfully balanced by a local
machine shop, J.B.Precision, to a Balance Factor of 50%. Our computer
model of the crank and counterweights turned out to be pretty accurate
because the shop didn't have to remove too much metal to
get the balance just right. We'll return the crank with the larger counterweights
attached and get it balanced to 60%. This will make it easy to evaluate
two different balance factors when the motor is ready to run. Counterweights
can be unbolted and removed through the sump without any other motor disassembly.
JUN 2010 Still waiting for quotes for the cylinder machining so we are
working on sump and oil pump design. Bill Dailey at Dailey Engineering
is making a pump for us and has been very helpful with info on dry sump
oiling system layout.
JULY 2010 Received oil pump
from Dailey Engineering and it's a very beautiful piece of machining
and engineering!
OCT 2010 Finally made a decision on the cylinder machining! Foreman
CNC is going to make two front and two rear cylinders. There aren't
too many local machine shops that can turn something this big on their
CNC lathes. Here are a few images
of the first machining operations for the cylinders.
A
test rig for evaluating trigger wheels and sensors is finished. The
sensor signal can be viewed on an oscilloscope at different crank speeds
and wheel-to-sensor air gaps. It is important to have a good, sharp
series of pulses at cranking speed and at maximum RPM. Here are some
images of traces recorded at
several different motor speeds.
Once the crank trigger wheel and sensor are sorted
out we will be ready to see about getting some cases made!
NOV 2010 The upper and lower case design mods are nearly
finished. Most of the changes have been done to make the machining easier,
although a 5-axis mill will probably still be required. The attached
3d pdf shows most of the latest part design updates (best viewed with
Adobe Reader 9).
APRIL 2011 We haven't made much progress over the last
few months. Still fiddling with final details on the case designs. Changes
were required to incorporate the chosen cam gears and chains. For the
prototypes, we will use chains, gears, guides and tensioners from a
Ford 4.6l modular motor, as used in recent Mustangs. The chains should
be strong enough for our application and after-market accessories like
adjustable cam sprockets are easily found.
Spiralock taps will be used to cut all the fastener threads
in the cases. These taps have a special shape that helps to keep the
studs and fasteners from loosening with vibration and thermal cycling.
We are still in the process of threading and evaluating test pieces
of aluminum.
All the fastener lengths and sizes are sorted out. ARP
studs, nuts and bolts will be used.
The front lower cam drive is shown in the picture, featuring
both an adjustable cam sprocket and crank sprocket. The upper cam drive
details are still not nailed down but we should be able to go ahead
with the case machining very soon.
JULY 2011 All the cam drive sprockets, link-belts and
roller chains have been finalized and sourced from Cloyes Gear and Products.
Their tech services department was helpful in finding chains with the
right pitch and number of links. Thanks Mike! We are waiting for quotes
for the machining of two pairs of cases.
New models of the cylinder head are almost completed.
The first version would have been very difficult to machine. The current
version has a number of changes to simplify machining, plus two more
parts. Updated 3D pdf to come soon!
JANUARY 2012 I'm concentrating on learning more about
CAM programming. After talking to a number of CNC machining firms over
the summer it seems like a good idea to re-do the CAD models of the
upper and lower cases to make them easier and less expensive to machine.
By working out the actual toolpaths and times required to make the parts
I can optimize the model shapes so that it might be possible to machine
them more quickly and to use a 4-axis Vertical Machining Centre instead
of a 5-axis VMC.
Meanwhile, Foreman CNC has been able to find some time
to move ahead with the cylinder machining!
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