Many years ago, as a young and somewhat naive apprentice, I was told by my training supervisor to go to the engineering stores and ask for ‘a long wait.’ Thinking that this was some form of specialised turning tool, I dutifully did as requested only to be told after 10 minutes at the counter “You’ve had your long wait, now clear off!” Engineers and former apprentices of a certain age might recognise my continuing embarrassment. So when the idea of the...
Historically, the relatively soft grey cast iron cylinder liner with its inclusions of graphite, correctly prepared, has made an excellent material when running against much harder chromium plated rings. However, the differences in thermal expansion between the liner and that of the aluminium alloy piston make it necessary to introduce a greater than desirable radial clearance to prevent piston scuffing and eventual seizure. As the specific performance increases along with larger diameter...
In the first RET Monitor Seals and Gaskets article, we started to examine the research which Trelleborg Sealing Solutions, a leading multi-national manufacturer of gaskets and seals, has published into the interaction of sealing compounds with biofuels. This research will cause fuel system designers to rethink material selection for sealing gaskets and O-rings. In that article we focused on water contamination of bio-diesel, something which is to an extent, almost inevitable. Water...
The process of engineering design is very much a compromise and sometimes, even with modern computerised techniques, several iterations may be required before the final, optimised product evolves. The design of a modern cylinder head can be a perfect example of this. Although four valves per cylinder with a central spark plug is ubiquitous in gasoline engines, as the included angle of the intake and exhaust valves becomes smaller, the architecture of the valve train and space for the...
You can’t talk about cylinder liners for very long without referring to the terms of either ‘wet’ or ‘dry.’ Although fairly self-explanatory, these refer to liners, which are either in direct contact with the engine coolant or those which are not. And at one time, and more years ago than I care to remember, these terms may also have referred to a certain type of Tory politician. In those recessionary times (yes, we had them back then as well!) monetary policy...