The Engine: The BUB Seven is powered by a custom V-4 engine. This engine is purpose built for motorcycle land speed racing. From a blank sheet of paper this engine was designed for one thing, power the world's fastest motorcycle.
The maximum limit for this land speed racing is 3000cc. The engine also needs to fit in a space 18 inch x 28 inched so part of the initial design is to fit this compact space. The V-4 concept was used for two reasons, one to fit into the packaging and two the unique surface of the salt flats requires a engine with traction control. The engine is a big bang type so that the engine can gain traction then relax and then transfer power with the next power pulse.
Most of LSR Racing is refining a concept from the problems that are usually
unseen until racing begins at Bonneville Joe explains the basic and shows the
engine's unique features in this video.
A new Motor Beginning ...
Denis had always wanted to design his own motor. One of the problems with LSR racing is the specialized type of engine needed. It has to make peak power, survive the 6 miles of hard acceleration and then repeat the whole thing going the opposite direction down the track. With all of that covered it must fit snugly in a compact streamlined shape .
In 1990 Denis had an idea of the perfect motor. It would be the just under the maximum displacement of 3000cc, a V-4, and incorporated the most modern cylinder head and transmission technology. That year Denis was a speaker at on of the Society of Automotive Engineer regional meetings. Denis showed the group his previous streamliners and pitched his current motor idea. As the meeting drew to a close a Joe Harralson an engineering professor approached him and vowed to stay in contact.
A month or so latter Joe came to Denis with working drawings and that was the beginning of the V-4 project.
The first step a was to take the drawings and convert them into patterns for the sand casting patterns. The patterns were designed for a conventional sand casting process. Joe tackled this step with experience he had from working at Mercury Marin and Mucula in their engine research divisions. He carved the patterns himself out of mahogany.
Pouring Metal ...
356 Aluminum alloy that is heat treated after casting is used. Melted at 1350 deg F at Betra Manufacturing, now based in Carson City NV.
Cores and ...
Sand casting patterns are made up of a Cope ( top mold ) and Drag ( bottom mold ) with Cores that create the void for holes in the casing. Part of the problem with casting a cylinder head is the chance that a core will break and cause a void in a water jacket or intake runner.
In this photo you can see the raw casting with the sand and part just after pouring. The are cleaned of sand and extra metal then sent for machining.
Inspecting Parts ...
This part is first inspected for flaws including voids, cracks and breaks.
|Machining Parts ...
The parts are CNC machined. This image is of the Cam Carrier of the cylinder head and the valve buckets.
|Multiple engine components are cast at the same time.|
Dyno Testing ...
The first engine configuration was normally aspirated and making 420hp and 380ft of torque. Now the engine is turbocharger generating 525hp and 420ft of torque. The engine is designed to withstand nearly double the amount of power before any modifications are needed.
The engine undergoes extensive dyno testing before it hits the salt.