Chevrolet small-block engine
After the 1967 Trans-Am campaign with the 4-Bbl induction system producing more horsepower than the competing auto makers' 8-Bbl systems, for 1968 Chevrolet developed a factory 'cross-ram' aluminum intake-manifold package using two Holley mechanical secondary carburetors for Trans-Am racing. It was available only as off-road service parts purchased over the Chevrolet dealership parts counter. With the Chevrolet '140 1st-design off-road cam, the package increased a stock 302's horsepower from to approximately . Chevrolet went so far as to carry the positive crankcase ventilation system (PCV) over to the cross-ram induction system to retain emissions compliance mandated for US-produced cars beginning in 1967, that also provided full-throttle crankcase pressure venting to the intake air to burn its vapors. Engines prepared for competition use were capable of producing with little more than the 8-Bbl induction, ported heads with higher pressure valvesprings, roller rocker arms, and the '754 2nd-design road-race cam. 1967/1968 models' cowl-induction system had an enclosed air-cleaner assembly ducted from its passenger side into the firewall cowl above the heater core. In 1969, factory Z/28's could be ordered with the ZL-1 aluminum-block 427 adaption of the 1967 L-88 427 Corvette cowl-induction 'ZL-2' hood available for both single and dual four-barrel induction systems that were sealed to the air cleaner base ensuring dense cooler, high-pressure, oxygen-laiden air from the center of the base of the windshield was supplied to the engine for combustion smoothness and maximum power production. Another popular service-parts-only component used on the 302 was the magnetic-pulse Delco transistor-ignition ball bearing distributor. Introduced in 1963 on Pontiac's drag racing engines, General Motors fitted it to the 1967 Z/28 before they used it on the L88 Corvette. It eliminated the production breaker-point ignition allowing greater spark energy and more stable ignition timing at all engine speeds including idle. This was one of the least talked about yet most transformative and comprehensive performance and durability upgrades of its time. Many of the 302s off-road service parts were the development work of racers like Roger Penske. Every part in a SCCA Trans-Am engine had to be available through local Chevrolet parts departments to encourage their use by anyone who wanted them.
Air-blast injection
Air-blast injection is a historical direct injection system for Diesel engines. Unlike modern designs, air-blast injected Diesel engines do not have an injection pump. A simple low-pressure fuel-feed-pump is used instead to supply the injection nozzle with fuel. At injection, a blast of compressed air presses the fuel into the combustion chamber, hence the name "air-blast injection". The compressed air comes from compressed-air tanks which feed the injection nozzle. A large crankshaft-driven compressor is used to re-fill these tanks; the size of the compressor and the low rotational frequency of the engine's crankshaft means that air-blast injected Diesel engines are huge in size and mass, this, combined with the problem that air-blast injection does not allow for quick load alteration makes it only suitable for stationary applications and watercraft. Before the invention of precombustion chamber injection, air-blast injection was the only way a properly working internal air fuel mixture system could be built, required for a Diesel engine. During the 1920s, air-blast injection was rendered obsolete by superior injection system designs that allowed much smaller but more powerful engines. Rudolf Diesel was granted a patent on air-blast injection in November 1893 (DRP 82 168).