Ladies and Gentlemen, introducing the undisputed champion of the world. Born in the USA, now fighting out of Perth, Western Australia and weighing in at 441 cubic-inches – the Bischoff Racing Engines Windsor.
Not too many years ago you would have been called a liar if you claimed your engine could produce 2hp per cubic inch without a device ramming copious fuel and air down its throat. Two-valve V8 engines simply don’t make that kind of power you bench-racing lunatic. But these days it seems – they do.
Each year, the cream of America’s engine builders spent mind-sapping hours designing, fabricating and testing their engines in a bid to compete for the ultimate crown in all of enginedom – the Engine Masters Challenge. Carried out under the strictest conditions imaginable, these engines are built to make the strongest average torque and power per cube (between 3500 and 7500rpm) and each year that challenge becomes more and more difficult as, in theory, they all approach a theoretical limit.
The 2011 competition was hotly contested but ultimately won by this Windsor, built by engine guru, and four-time winner, Tony Bischoff. It seemed that before the flowers had wilted and the champagne had stopped bubbling, the engine was enjoying its new celebrity with an all-expenses paid trip to sunny Western Australia. Ready to greet the import the minute it touched down was Leon Withnell from A1 Hi Performance in Myaree.
Leon had purchased the engine as part of his own, ongoing engine development programme. “We have a great relationship with several US companies and our engine building theories, ideas and data flow both ways,” Leon added. “Our learning curve is relentless and my goal is to improve every engine we build, there are always areas to study and develop that yield power and torque gains and we apply each new discovery to the next engine we build.”
The 441 Windsor has just taken on the best in the business and come up trumps so it is a worthy addition to A1’s R&D programme. The level of detail and the time spent modifying and improving what may seem like minor areas of the motor, all combine to produce a super-efficient package capable of some stellar output figures.
As soon as the engine arrived here in the West, it was sent off to C&R Motorsports in Walliston, where it hit the engine dyno for a direct comparison against its US stats. Both dynos are Superflow 902s so there was a great deal of parity. The test conditions in the US tend to be more humid (particularly where Bischoff’s workshop is located) but the figures did align very closely. After seeing the Perth test figures, Bischoff suggested that the engine was running a little lean in our good local air and that the timing could have been nudged up a couple of degrees – both valid reasons for Leon to revisit the dyno.
The hardware found on this engine is second to none but, as is the case with most things, simply bolting together a bunch of top shelf gear does not guarantee a world-beater. It takes a great deal of knowledge, experience and attention to detail to build an engine capable of delivering such impressive figures. This is a perfect example of parts working in unison to create a synergy – everything, and we mean everything, is done for a reason with one goal in mind.
One excellent example of this is oil return from the cylinder heads. The key here is to make sure that not one drop hits either the camshaft or the crankshaft on its way back to the sump. To this end, the return holes in the valley are blocked and fitted with screw-in risers for venting the sump. The risers are tall enough not to allow any oil to flow down them. At the end of each cylinder head is an anodised fitting and a braided line that takes the oil from under the rocker covers back to the sump externally. The sump itself is incredibly deep to keep the oil as far away from the reciprocating crank and rods as possible. This is only one example of the level of detail in the 441.
Naturally, the trick to making such impressive power figures is a great pair of cylinder heads. Bischoff started with a set of Edelbrock Glidden SC-1 heads that were machine ported at Bischoff Engine Services (BES) and now flow 440cfm on the intakes and 300cfm on the exhausts. The ports were cut to the exact size and crosssectional area, as dictated by the engine’s displacement, and were also offset in relation to their standard position. Offsetting the ports allowed for a straighter flow path from the intake manifold to the valve. Titanium valves were used, along with top-shelf Jesel rocker arms and PSI springs with 1000lbs of pressure on the nose. The Comp cam is not overly aggressive at 252/262° duration at 50-thou but with a massive rocker ratio of 2.00 and 2.08:1, the modest lobe lift translates to .940-inch lift at the valve. The cam was ground on a larger 55mm journal that allows a stiffer cam
Another source of frictional losses is drag in the bore. To combat this enemy Bischoff fitted Total Seal rings: gapless for the top; Napier face profile for the second and a narrow 3mm oil ring pack. The net result is a total ring pull of just over 9lbs, which translates to a total engine rotating torque without the valvetrain of only 8-10 lbs/ft. Custom Ross pistons were used. These feature a dish to provide 14.5:1 compression and an in-board pin boss that allows a shorter, lighter gudgeon pin to be used. Additionally, the in-board boss design makes the piston very rigid despite being very light.
Induction is critical when it comes to producing the broadest possible spread of power and torque. Tiny factors such as runner taper and length can have a huge affect on not only how much power is produced but also where it is produced in the rev range. To this end, Bischoff fabricated a large plenum spacer that sits on top of the Edelbrock intake manifold. Internally, the plenum is blended so as to become an integral extension of the manifold. Above that is another spacer that sits under the huge 1250cfm Pro Systems Dominator carburettor. The carburettor has adjustable air bleeds and some tweaking of these was needed – along with the main jets – to reach optimum output during the Engine Masters’ dyno testing. On the opposite side of the equation, the BES team spent many hours on their own dyno altering the primary pipe lengths of a set of Schoenfeld sprint car headers. Once again, they experimented with the pipe lengths to create the highest average, not peak, numbers.
Firing the brew was down to a complete ICE ignition system from CDI to coil to distributor. Bischoff swears by the ICE system and claims he has seen measurable power gains from using their components over their competitors’ gear.
So, when all was said and done what sort of power do you need to take out the title from the best engine builders in the world? Well, a peak number of 913hp at 7200rpm will go a long way towards getting you there. Peak torque was an incredible 729lbs/ft at 5900rpm. Just sit and digest those numbers for a minute. 913hp from 441 cubes means 2.07hp per cubic inch. It also produces 1.66lbs/ft per cubic inch – not so many years ago it was thought that the theoretical maximum for a petrol engine was 1.50. At the test starting point of 3500rpm the engine made 563lbs/ft and 375hp. By 4300rpm it had cracked 609lbs/ft and 499hp. At 6000rpm it made around 830hp and by the end of the test at 7500rpm it was holding 906hp and 634lbs/ft torque. Those figures give an average torque figure of 680lbs/ ft and an average power figure of 720hp – over a 4000rpm range!
With such an incredible spread of power and torque, this engine has all the characteristics of the ultimate street engine, despite making more power than many dedicated race engines and that is the key to the whole exercise – making broad, efficient and useable power and torque. Impressive peak numbers do not make for great street cars or even quick ETs necessarily. In that vein, Leon is developing a series of engines to compliment his line of crate motors. There will soon be a genuine 700hp street engine, an 800hp bracket racing engine and a 575hp (363 CID) Windsor. Stay tuned for a new generation of champions.
The key to all that power is the radically re-worked Edelbrock Glidden SC-1 cylinder heads that flow 440cfm on the intakes and 300cfm on the exhausts.
Custom Jesel shaft-mounted rockers have an extreme 2.00/2.08:1 ratio. They have to cope with 450lbs of pressure on the seat and 1000lbs on the nose.
At the end of each cylinder head is an external hose that allows oil to drain back to the sump. Keeping the oil outside the engine eliminates the risk of it falling back onto the camshaft or the crankshaft and creating power-sapping drag.
Re-printed from Volume 20 Number 1 of Perth Street Car Magazine with permission.