Engine

  • 5700cc Chevy small block (plus 0.03"), fitted with twin Sprintex superchargers
  • Brodix -8 aluminium heads
  • Moroso dry sump system
  • Motec M48 pro ECU
  • Motec traction control Multiplex
  • Motec ignition expander
  • Distributor less ignition system
  • B & M supercharger cam and followers
  • Eagle forged steel crankshaft
  • Comp cams roller rocker and push rods
  • ARP studs throughout
  • Air to water intercooler
  • TWR forged pistons
  • Manley steel rods
  • Custom stainless steel exhaust system
  • Flowmaster silencers fitted with Supertrapps
  • Victor Junior inlet manifold, modified to accept the fuel injectors

The main feature of the engine is the twin sprintex superchargers, these are screw type compressors as opposed to roots type. The drive consists of an idler shaft running the length of the engine, each blower is then in turn driven from this shaft. The cooling system comprises of a 928 radiator mounted at the front, aluminium tube runs the length of the car. Wiggins fittings used throughout.

View from inside passenger compartment, showing main blower drive. As can be seen the water pump is missing. This has been moved to the back of the engine and driven by the idler shaft. I had to move the pump to reduce the intrusion into the passenger compartment.

Engine

The dry sump tank can be seen on the left.

Engine

Engine installation part way through.

Engine

An even earlier view.

Engine

I had a lot of trouble with under bonnet temperature. One of the solutions was to case the exhaust in an aluminium box lined with heat reflective material. Below 25mph a fan blows air through the box, above 25mph a flap opens, the fan turns off and scoops air from under the car. The speed at which this occurs is controlled by the ECU. The Motec is a very powerful system, with configurable outputs to control anything you want.

Engine

Air intake and ECU controlled flap.

Exhaust-Scoops

View showing exhaust cooling fan.

Exhaust-Fan

When I drove the car for the first time and the blowers started to make boost, I became very aware of their presence right behind my head! Although screw type compressors are not susceptible to exploding, I decided to make some Kevlar shields and restraint straps. The first layer is Kevlar/Carbon Hybrid for show, the rest are Kevlar only (20 layers of 170g).

Blower-Shield

An air to water intercooler is employed, as opposed to the more common air to air. There is more work involved with an air to water system, but I would have struggled to find somewhere to mount the large intercooler element used in an air to air system. A CB400 motorcycle radiator is used to remove heat from the cooling liquid. The heat exchanger is mounted directly above the inlet manifold and was originally designed for marine turbocharger applications. An electric water pump is used to circulate the cooling liquid and is manufactured by Jabsco 59500 Series. An electric fan draws air through the radiator at slow ground speed, this is controlled by the ECU and switches off at a predetermined speed. The electric water pump turns on at a predetermined engine temperature and then stays on, in fact the fan will not turn on until this temperature is reached as well.

Intercooler-Rear