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Recent content by EHudson

  1. EHudson

    Material selection - Cylinder sleeves

    Cast iron is a good bet for most piston and ring combinations. As for steel, aircraft cylinders are nitrided for wear and chrome rings work against that material. Regular steels are not so good for cylinders. If your cylinder is rigid enough on its own you can have it plated with...
  2. EHudson

    Magnetos

    The Magneto Ignition System by John Schwaner, Aircraft Technical Book Co., www.ACtechbooks.com
  3. EHudson

    Differential crown gear

    Working on the assumption that your "convex" and "concave" refer to the spiral direction in the spiral bevel gear I offer this conjecture: Gears develop a separating force that is a function of the tooth pressure angle. In a bevel set this separating force generates thrust on the gear set away...
  4. EHudson

    Some of the worse designed engines?

    As I understand it, the unbalanced firing in racing motorcycles is done to help the rider feel when the rear tire is slipping during the power pulses and give a brief interval for the tire to regain a bit of traction before the next series of power pulses. This is in contrast to some F1 engines...
  5. EHudson

    Flexplate design: misalignment and fatigue

    In my opinion, an example of an under designed flex plate was a unit on some 60's Chrysler products like the 273 powered Barracuda and others. This flex plate bolted to the crank with six bolts if memory serves and had two steel arms that bolted to the torque converter near the starter ring...
  6. EHudson

    Carbon fiber fuel tank

    There are emission requirements for fuel systems. Lots of tanks are blow molded with multiple layers containing different resins that are resistant to hydrocarbons, alcohols and other components. It is not a simple stamping any more.
  7. EHudson

    internal combustion gas or diesel engine clean sheet designing

    The net effect is a weight savings by allowing a shorter pin with a larger I.D. to carry the loads piston loads. Diesel allowable pin bore pressures have more than doubled in the last 60 - 70 years from perhaps 60 ksi to 140 ksi. Fit, finish and some design tricks account for much of the...
  8. EHudson

    internal combustion gas or diesel engine clean sheet designing

    TugboatEng - Nice picture illustrating the teepee shaped small end of the connecting rod. The lower half of the pin bearing bore has more area for combustion gas loading compared to the inertia loading on the top half. The piston bosses are moved in at the top for additional bearing area and...
  9. EHudson

    internal combustion gas or diesel engine clean sheet designing

    Those floating bearings were the width of two connecting rod big ends on the V8 Ford crank. The components (rods and bearings)were also used in a refrigeration compressor at least through the 70's. Floating bearings are not dead. Today you will find floating bearings on turbocharger shafts...
  10. EHudson

    internal combustion gas or diesel engine clean sheet designing

    I was challenged to design a four stroke engine that would fit under the cowl of an existing two stroke. The design was done on paper but I used a calculator not a slide rule. (yes, I have them). The crank, block, head, piston, rod, flywheel, cam and valve gear were clean sheet. First line to...
  11. EHudson

    internal combustion gas or diesel engine clean sheet designing

    Greg is correct. Rotating and piston assemblies first. Have the packaging requirements in mind. Engine design is all about packaging once you have in depth knowledge of the individual components (no small thing). Pick a reasonable BMEP not something over the moon. Pick a reasonable piston...
  12. EHudson

    Dynamic torque signature

    A classic text on the subject has recently been reprinted: https://www.amazon.com/Handbook-Torsional-Vibration-J-Nestorides/dp/052120352X Missing from the reprint is a fold out detailing formulas for various dampers which is attached as a .pdf, for educational purposes, with a small change...
  13. EHudson

    F1 engine, deck ridges ?

    I have used the 'c' shaped cross section seals with internal springs as head gaskets. see page 21 of TugboatEng's reference. The volume was relatively small and emissions weren't an issue. First saw them mentioned for head gasket use in a book on diesels if memory serves. Mercury Marine...
  14. EHudson

    F1 engine, deck ridges ?

    The bore seals may be of the 'U' or 'C' shaped cross section copper rings. These have the opening towards the combustion chamber and are energized by combustion chamber pressure and sometimes an internal coil spring. There may also be a coil spring inside. Because gas pressure inside the ring...

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