Thus far we have examined the application of titanium in the production of racing valves, and seen how the properties of this material may be tailored to the application by either specific heat treatments, or by combining materials with different mechanical properties within the same valve by the use of friction welding. We reflected on the fact that titanium, compared to steel and most of the other materials that we would traditionally use for valve manufacture, offers a lower mass valve when properly optimised. Read more…
Archive for October, 2009
POPPET VALVE MATERIALS
Monday, October 12th, 2009GOING CUSTOM FOR LONGEVITY
Monday, October 12th, 2009
The overhead cam Suzuki engine campaigned by 2007 NHRA Full Throttle Drag Racing Series Matt Smith in the Pro Stock Motorcycle category “pretty much controls the valves,” according to engine builder Steve Tartaglia. “Because we don’t run pushrods,
I think the biggest weak link we have is in the camshafts and cam chains. It’s not anything that significantly flexes; it just varies the valve timing more than we’d like.”
The solution Tartaglia has found in his valve spring composition is going from off-the-shelf componentry Read more…
SEQUENTIAL GEARBOX ORIGINS
Monday, October 12th, 2009
In previous Monitor features we have touched upon the automated gearshift of a modern race car and attempted to put it into historical context, but how many of its mechanical design features represent new thinking ?
Central to its function has been the move from a H-gate to sequential gear selection, for with this it is much easier to provide powered control of the actual selection mechanism. In the modern box this normally takes the form of a drum, with a pathway machined into it, whose axis is parallel to that of the actual gear shafts. Read more…
WHICH HARDENING METHOD IS BEST?
Monday, October 12th, 2009
Last month we looked into induction hardening of crankshafts and the inherent differences between that process and nitriding.
We saw that induction hardening carries significant potential benefits; the main one being that the crankshaft is only heated locally which means that distortion can be effectively managed.
There is also no maximum limit on case depth with Read more…
SEALING THE FUTURE
Monday, October 12th, 2009
One of the world’s leading race engine manufacturers has revealed their design philosophy regarding seals and gaskets to RET Monitor this month.
Dave Salisbury, Chief Design Engineer at Engine Developments Ltd (EDL), told RET Monitor, “It’s a simple philosophy really… we just work hard to eliminate seals and gaskets wherever we can.”
Whilst that sounds straight forward and much like common sense it is actually something which is very hard to Read more…
THE OIL CONTROL RING
Monday, October 12th, 2009
If the top compression ring has the most difficult of tasks in the engine then, at the other end of the piston ring pack, the oil control ring doesn’t have it much easier. Travelling at an average speed approaching 4000 feet per second or so, the component has to strip away any excess oil from the cylinder bore on the downward stroke and ensure just sufficient passes to lubricate the upper rings. The excess oil is then forced through the ring and drains back to the crankcase via a series of slots or holes in the piston. Read more…
ENDING THE BEND
Monday, October 12th, 2009
Although Funny Car engines get torn down from top to bottom end between 1000-foot NHRA Full Throttle Drag Racing Series passes, it’s easy to overlook pushrods “because they are that good,” according to 2008 series runner-up and 2009 Countdown to One participant Tim Wilkerson. He’s been using “nothing but Manton pushrods” in his engines for many years citing, “Terry’s got a good product and he’s quick to fix something if it’s wrong.”
The clearance difficulties inherent with a nitro-burning Read more…
IT’S ALL ABOUT CONSISTENCY
Monday, October 12th, 2009
For John Force Racing co-crew chiefs Dean ‘Guido’ Antonelli and Ron Douglas, the 2009 Funny Car season has been all about consistency. Include the selection of Venolia pistons in that mix because, as Antonelli points out, “In our current configuration, the pistons are relatively the same on all eight cylinders. They may vary from cylinder to cylinder, depending on the distribution of air coming out of the blower,” he allowed.
If the pair are getting driver Ashley Force-Hood down the track without hurting any parts, they can easily stay Read more…
VARIABLE FLOW OIL PUMPS
Monday, October 12th, 2009
The science of engine development is one of incremental steps; small but measurable increases in power over a period of time. Improvements in port flow, increasing the engine rev limit or changes in intake or exhaust system sizes will, no doubt, help. But while that is undoubtedly the high profile, glamorous part of development, as far as engine performance goes, it is only half the story. The other, perhaps less glamorous part is that of minimising the parasitic losses; the friction in all the sliding components and the power to drive all the auxiliary drive systems - which includes of course, the oil pump. Read more…
ALUMINIUM MATRIX COMPOSITES
Monday, October 12th, 2009
Although cast iron cylinder liners have always been a safe and reliable choice, the differential expansion rate between them and the aluminium pistons, as well as their shear weight, has always encouraged designers to look for better alternatives. When cylinder blocks were cast iron, engines were so heavy as to make any change in the cylinder liner material utterly futile but as demands for lighter engines made aluminium more attractive, the push towards some kind of aluminium cylinder liner was only to be expected. Read more…
