The fuel injector is an electromagnetically controlled device designed to meter fuel to the engine, and at the same time offer it in a form such that it can be readily combusted. Presented in this way, the task of the injector would therefore seem to be fairly straightforward, and over the years a number of designs have been offered. Pintle-type injectors, ball-and-seat designs through to simple disc derivatives – each new design has been slightly more tolerant to the build-up of...
A race engine is effectively an air pump and, in theory at least, the greater amount of air it passes then the greater amount of power produced. However, the introduction of the inlet (or exhaust) valve to control the flow into (or out of) the combustion chamber brings with it a number of practical limitations, one of which is the potential for restricting or biasing the flow around the valve seat when at partial lift. Engineers have grappled with this problem for many years, and while the...
All engines suffer from a degree of ‘blow-by’, where combustion gas escapes past the piston rings into the crank case. While the movement of pistons and other reciprocating components contributes to crank case pressure, the biggest single culprit is blow-by, and the resulting pressurisation needs to be vented from the engine. If this pressure isn’t relived, it can cause oil to be pushed past the various crank case seals, notably the main crank seal; it will also impact the...
As discussed in previous RET-Monitor articles and in the pages of Race Engine Technology magazine, reducing the mass of a piston assembly is especially valuable because it then allows design engineers to reduce mass of all of the downstream components. The piston pin is a significant mass, and any reduction here allows weight to be removed from an optimised con rod and crankshaft. The temptation is to make piston pins smaller in every dimension – that is, outside diameter, inside...
The carburising process has found very wide use in motorsport as well as the wider engineering industry. It provides a hard surface on a tough core, and puts the surface of the component into a state of residual compressive stress, which we know have a positive effect on component life. The number of applications for carburising is growing, owing to the adoption by many companies of low-pressure carburising (also referred to as vacuum carburising), and we covered this subject briefly in a...