In the previous article on the subject of maintaining the accurate locations of the two parts of a split con rod design, we looked at dowel pins and ring dowels, and the relative merits of the two methods. The subject of joint shear stiffness was raised, and it was noted that the ring dowel, having a greater cross-sectional area, provides more stiffness to the joint. A stiffer joint is more stable and less likely to suffer from joint face fretting wear. While the con rod bolt may not have...
In the previous article on the subject of adding tungsten counterweighting to crankshafts, we looked at one of the more widely adopted methods where cylinders of tungsten alloy are pressed or shrunk into specifically machined bores in the counterweights. The conclusion that many crankshaft manufacturers and design engineers have come to is that this is a reasonably effective method of adding tungsten while affording generous safety factors against failure. It is also simple from a...
Like millions of other followers of Formula One, I look forward each year to sitting in front of the TV and watching both practice and race of every single Grand Prix throughout the season. Also like many others, I have done this for probably the best part of 30 years, for as long as the sport has been covered by prime-time TV. I always enjoy some of the on-board coverage looking over the driver's shoulder. In particular, I marvel at the way that 750-plus bhp can be tamed by our heroes...
This is a follow-up to my earlier articles on cylinder head loading. Earlier, I described what is known as one of the most critical failure modes, Thermo Mechanical Fatigue, or TMF. In those articles the three main load cases were mentioned - assembly loads, (peak) firing pressure load and thermal load. For thermal load, further insight was given into the design of the cylinder head cooling jacket. The conclusion was that the jacket is mainly derived from the rest of the structural design,...
It is surprising how often people get mixed up between the prefixes 'hypo' and 'hyper'. While 'hypo' refers to a situation that is less than normal, 'hyper' relates to exactly the opposite. As an example of such confusion I have a neighbour who speaks with a highly refined tone and continually refers to her 'hyperchondriac' husband, when I am sure she means 'hypochondriac.' So too are the differences between hypoeutectic alloys of aluminium and...