This very special 429 Smallblock Ford is the culmination of months of contemplation and calculation. No detail was too small as every aspect of the engine contributed to the greater good – reducing frictional losses.
Leon from A1 Hi Performance, in Myaree, has wanted to build this engine for years. His last engine, ‘Cat Killer’ was ahead of its time for an EFI Ford but Leon knew that his latest engine would eclipse that performance due to a continuous programme of study and development that centred around looking at an engine holistically to examine how each component and system inter-relates and to maximise the potential of each of these areas.
This philosophy recognises that the whole is definitely greater than the sum of its individual parts, synergy can be created in the world of engines but not without an intimate understanding of how each facet contributes to power production and – just as importantly – how it contributes to minimising parasitic losses. In Leon’s own words this engine is over the top in this respect but it puts into practise the theories and current state of play in the upper echelons of the engine building world, focussing on areas that free-up hidden power to the flywheel.
In a nutshell, these areas include airflow into and out of the engine, intake and exhaust valve timing events, positive and negative cylinder pressures, frictional losses and optimal ignition timing. It may sound simple but there is a long list of variables under each category and they are all affected by each other to some degree.
Everything is done for a reason in this motor and it starts with the bore, rod and stroke ratio. Essentially, large bores provide greater valve unshrouding and short strokes create lower relative piston speeds that enable higher rev limits to be achieved. Higher rev limits permit higher horsepower figures to be generated as horsepower is a function of torque and rpm. The rod to stroke ratio also determines at exactly how many degrees past top-dead-centre (TDC) maximum piston speed will be reached and this is around the point where maximum cylinder filling occurs. Once you know this, then you can select an appropriate camshaft with the correct opening and closing events but not until you consider the flow characteristics of the cylinder heads. Valve seat angles and the point where the intake valve reaches maximum lift are critical factors in this equation. Then there is the impact of the intake manifold to be considered. These factors are also influenced by the static compression ratio as this effectively determines the length of the power stroke when viewed in conjunction with valve timing events. Choosing parts from catalogues can get you close to an efficient combination, once you understand each concept, but the object of this engine was to push the boundaries much further and develop a truly custom engine capable of achieving nearly 1.9hp per cubic inch on unleaded fuel.
Pursuit of Parasites.
What may be harder to pick up in the photographs is the diameter of the big-end journals. These have been ground to a miniscule 1.850-inch – smaller than the popular Honda journal at 1.880- inch and far smaller than a standard Cleveland at 2.311-inch. Once more, the smaller pin requires a smaller big-end on the conrod which will naturally be lighter as a result. But consider also that the smaller pin requires a smaller bearing circumference and that results in less rotational friction at any given rpm than a larger conventional bearing diameter. Incidentally, those bearings are actually individually chosen from different sets to achieve the most accurate and consistent clearances possible. If the pistons were a work of wonder then consider the rings. Over 50% of an engine’s internal friction is generated by the rings traversing the bores. A conventional performance ring pack will have .062, .062 and .185 (1/16, 1/16 and 3/16-inch) top, second and oil rings. These new pistons have .037-inch top rings, .043-inch second rings and .080-inch oil scraper rings. That means a reduction of 48% in surface contact area, resulting in only 8.25lbs/ft of torque required to rotate the assembled short motor and only 25lbs/ft needed to rotate the fully assembled engine – with 850lbsplus valve springs!
|CHI canted valve Cleveland heads were selected for this engine – custom ported with 290cc intake runners to suit the 429 CID. A1 have fitted non-standard valve seats to both inlets and exhausts (not 45°) to reduce reversion during camshaft overlap periods.A1 fabricated the custom 2-inch primary pipe headers that feature a four-into-one design and merge collectors.This intake manifold has been completely cut, shut and fabricated to suit this unique engine. It is one of three that will be tested when the engine hits the dynamometer.A side profile of the fabricated manifold shows the inverted funnel design from the carburettor to intake ports.The camshaft has around 800-thou of lift and now spins in needle roller bearings.|
|The Winberg custom 3.900-inch crankshaft is super lightweight and has been chemically polished for low windage.||A view of the dummy assembled short. This revealed that the initial crankshaft sourced for the engine had 12-thou too much end float and was unsuitable for use. This led to the new chemically polished crankshaft being supplied as a replacement and used instead.|
|Extra coolant holes have been drilled in the block with corresponding holes also drilled in the cylinder head. This helps to eliminate hot spots and even out power production from cylinder to cylinder.||The assembled short motor with the Jesel timing belt fitted. This will only be used for dyno testing due to the ease of camshaft timing adjustment. Once in the car, a conventional timing chain will have to be used in order to achieve the correct pulley alignment for the serpentine belt drive system in the AU Falcon host.|
|A look inside one of three separate manifolds that will be tested on this engine when it hits the dyno. Each manifold has had extensive internal modifications made to optimise its performance with this special engine.||A close-up of the external oil drain that leads from the rear of each head to the sump. Re-routing the return oil in this way is critical in reducing oil windage losses inside the engine.|
|This is a one-off valvetrain that utilises T&D stainless steel roller rockers. The entire girdle that sits underneath and locates the rockers was custom made for this engine. A girdle such as this for a canted valve engine is no simple matter to construct as each rocker is on a separate angle of tilt and rotation in relation to the engine centreline. Many hours of machining were consumed in the manufacture of these two girdles.||On dyno the engine will be run up with this Pro Systems 1250 Dominator carburettor. When the engine is bolted into the AU, it will switch to the massive 1400cfm EFI throttle body and be Motec managed.|
|An AU Falcon timing cover was modified to fit around the Jesel timing belt and also to accept an electric water pump with an idler pulley for a serpentine accessory belt. The MSD crank trigger is hooked up to an ICE ignition.||On dyno the engine will be run up with this Pro Systems 1250 Dominator carburettor. When the engine is bolted into the AU, it will switch to the massive 1400cfm EFI throttle body and be Motec managed.|
|Windage is a term often heard but seldom understood. It refers to drag created by rotating or reciprocating parts as they pass through air and oil inside the engine. Hold your arm out the car window and you will feel wind resistance, hold it out the window of a jet plane and it will be ripped off – that is the dramatic effect of wind resistance and it occurs inside every engine. The effect is multiplied when those components come into contact with oil inside a motor. If you have ever done a belly flop in a swimming pool then you will have some idea of what a crankshaft encounters when it hits oil in the sump. Modern race engine builders pay great attention to reducing windage because by doing so they have more horsepower available at the crankshaft for doing work.In this 429 no oil returning to the sump is permitted to come into contact with the camshaft or the crank and rod assembly. Oil from under the rocker covers and from inside the valley isplumbed externally and routed back directly into the sump. Inside the custom luminium sump is a series of windage trays and baffles that prevent the crankshaft from whipping up oil and vapour and creating windage. Other modifications have also been made to further reduce windage inside the engine.
In an additional nod to reduced friction, the camshaft now spins in needle roller bearings rather than conventional white metal bearings and is retained by a Torrington bearing thrust plate behind the Jesel belt drive.
The engine is now together and will soon be heading off to the dyno for some rigorous testing and serious power runs. The object is to produce in excess of 800hp using Ultimate 98 unleaded fuel and to maintain street driveability in the process. Stay tuned for the dyno tests next issue.
“The object of this engine was to push the boundaries and develop towards 1.9hp per cubic inch on unleaded fuel.”