Bad Dog Cycles
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build, page 2
Build, page 2
Crank was successfully balanced by a local machine shop, J.B.Precision, to a balance factor of 50%. The computer model of the crank and counterweights turned out to be pretty accurate because the shop didn't have to remove too much metal tobalance holes get the balance just right. The crank will be re-balanced to 60% with the larger counterweights attached. 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.

Dry Sump Diagram Still waiting for quotes for the cylinder machining so onward to sump and oil pump design! Bill Dailey at Dailey Engineering is making a pump for the motor and has been very helpful with info on dry sump oiling system layout.

Received oil pump from Dailey Engineering and it's a very beautiful piece of machining and engineering!

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!

The upper and lower case design mods are nearly finished. Most of the changes have been done to make the machining easier. The attached 3d pdf shows most of the latest design updates.

Not 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, chains, gears, guides and tensioners from a Ford 4.6l modular motor  (recent Mustangs) will be used. 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. Threading and evaluating test pieces of aluminum is underway.

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 case machining ahould be started soon.

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!

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!

Bill is concentrating on learning more about CAM programming. After talking to a number of CNC machine shops 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 the model shapes can be optimized 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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