If a valve spring for a race engine is to survive a service life of 1400 race miles or 1600 absolute miles then it needs to be robust and reliable. In the Indy Racing League’s IZOD IndyCar Series, where the Honda Indy V8 is the sole motive power, Honda Performance Development (HPD) has gone with a steel, flat-top, double-valve spring without insert, to achieve the balance needed on road courses, street circuits, short ovals, speedways and superspeedways. Read more…
Archive for May, 2010
Selecting for robustness and reliability
Thursday, May 13th, 2010Transmitting power
Thursday, May 13th, 2010
With the adoption of independent, or de Dion rear suspension by racing car constructors during the 1930s, some means of transmitting the torque from the transmission into the wheel hubs had to be devised that accommodated the vertical motion of the wheel.
When using a swing axle, this was usually achieved by using a ball-and-socket arrangement integrated into the differential output shafts, while fully independent and de Dion systems required some form of universal joint at each end of the driveshaft. Read more…
Anodising
Thursday, May 13th, 2010
Aluminium offers many benefits to mechanical engineering designers, and racing engine designers have long been keen to exploit its low density and good strength. There are now aluminium alloys commercially available with tensile strengths well above 700 MPa (>100 ksi) and the development of alloys for specific properties has accelerated in recent years.
One disadvantage with aluminium, however, is its propensity to oxidise - anyone who has left their Read more…
Crank seal revolutions
Thursday, May 13th, 2010
If you thought it was only race engine manufacturers who are paranoid about friction at the crankshaft seal, think again. The inexorable push towards ever lower CO2 emissions - better fuel economy to you and me - is making many an original equipment (OE) engine component supplier look much more closely at its products.
Chief among these is Federal-Mogul, which has just introduced a ‘new approach’ to lip seal technology, Read more…
Revolutions in Rings
Thursday, May 13th, 2010
For as long as I can remember, it has been considered best practice to position the ring gaps equidistant around the piston. The theory is that in doing so, gas leakage will be minimised so that it stays within the confines of the combustion chamber, expands and generates more shaft power. For some reason - and I no longer understand why - it just made common sense and was never really challenged. Read more…
Solving pushrod fitment challenges
Thursday, May 13th, 2010
While pushrods may not have a place in (relatively) unrestricted, top-flight racing engines any more, they are still a part of the racing landscape in many forms of racing, whether by regulation or through financial expediency.
NASCAR, of course, mandates the use of a pushrod engine in all its racing series, along with a single block-mounted camshaft and a controlled height above the crankshaft. Like almost every part of a racing engine, pushrod design is the subject of a Read more…
Longevity and performance
Thursday, May 13th, 2010
When Honda Performance Development (HPD) began plans to enter the Indy Racing League in 2003 with the Honda Indy V8, it built an engine that would have a service life of 600 miles, made to last from Carburetion Day at the Indianapolis Motor Speedway through the Indianapolis 500.
Much has changed since then, as HPD became sole engine supplier in the 2006 IndyCar Series season. Now the engines have a service life of 1400 race miles or 1600 absolute miles, as Roger Griffiths, Read more…
Dry sumps - the alternative
Thursday, May 13th, 2010
We live in a world of choice, or so our politicians would have us believe. But when it comes to engine oil systems for racing, is there anything other than a dry sump that can do the job? I would argue not, but despite that there are still authorising bodies or rule setters out there who insist on banning the systems, even though the alternatives are far inferior and these days probably no cheaper. Read more…
Liner Distortion
Thursday, May 13th, 2010
Spare a thought for the poor cylinder liner. As well as expecting it to be perfectly round from the outset, we then go on to expect it to remain so throughout the rest of its life, and under the most arduous conditions.
But are we making it as round as it could be? Take for instance the typical case of a replacement dry liner. We’ll measure its external diameter in at least three positions around its axis, and then again in another three places up and down the bore. Read more…
KERS spreads its wings
Thursday, May 13th, 2010
So far, KERS systems have received a mixed response in Formula One. Initially the technology was eagerly tested by the teams but during its first full season in Formula One (2009), it was regularly used by only a few.
In truth, Formula One KERS still have some way to go before their advantages sufficiently outweigh the disadvantages, so it is perhaps in their wider application in motorsport that they will be fine-tuned and their advantages eventually fully exploited. Read more…
