Up until the end of the 1950s, when the front engined Grand Prix car predominated, it was not uncommon to find it’s transmission attached to the engine bell housing, in classic road car configuration, with the box itself almost always in-line, and often road car derived. But it was equally the norm to find the transmission in unit with the rear axle and differential, particularly in a thoroughbred racing design, in which case it was as common for it to be aligned transversally, as in-line.
When the mid-engined car began to take over Read more…
There are valvetrain tricks to making good power and obtaining durability and longevity from a Dodge Mopar USAC National Midget engine, according to engine builder Bob Wirth of Hayward, California. “We need them all.”
Race engine crankshafts are typically produced from steel billets and are gas nitrided to improve fatigue life and reduce wear.
In this and future issues we will look at one of the most critical seals in a race engine, the seal between the top of the cylinder bore and the cylinder head.
Mention the subjects of durability and wear measurement in engine development and the image immediately conjured up is one of tests lasting hundreds of hours and lots of precise measurements, both before and after the test. When it comes to the piston ring we might want to check the ring gaps both free and as installed, measure the weight as accurately as we can, take a few harness measurements and visually examine the wearing surface. Apart from that there is little extra even the well-resourced development lab can do. Of course the rings may well be returned to the supplier for more 
When engaged in building Dodge Mopar engines for use in USAC’s National Midget series, Bob Wirth of Hayward, California relies on pushrods from Smith Bros of Bend, Oregon.
Mark Smith’s PME Engines of Mooresville, North Carolina powers the NASCAR Camping World Truck Series (CWTS) entries of Ron Hornaday Jr and Matt Crafton, currently first and second in points as the campaign hits its home stretch.
Last month we looked very briefly at gear pumps, in particular, external gear pumps when two gears sit side-by-side. A particular derivation of the gear pump however, sometimes referred to as an internal gear pump or internal-external gear pump is when one external gear fits inside a rotor consisting of an internal gear. With the centres of each gear offset from one another and a differing number of teeth on each of the gears, rather like its external counterpart, the resulting cavities can be made to pump fluids. A specialised form of this design which, rather than using an involute tooth profile 
It is a fact not appreciated by many, except the specialists, but the technology of the cylinder bore surface finish has changed significantly over the years. While oil consumption was perhaps the greatest driver in the past, the push to achieve even less and less exhaust emission at higher and higher mileages, has caused OE engine manufacturers to focus even greater resources into getting the surface finish of the cylinder bore exactly right. And while, to the OEM this means emissions approval, to the racing industry this technology brings less friction and wear and with it, improved performance. 
