Engine
An all-alloy 24-valve 3.2L quad-cam V6 complete with supercharger...Engine
 |
The engine is an all-alloy 24-valve DOHC 3.2l V6 (model 6VD1-W), straight from a Amigo/Rodeo in the good ol' US of A. The block is reasonably stock aside from the use of platinum centre-fire plugs and being dry-sumped. To run the dry-sump pumps (3 of) and the power steering pumps (2 of) a counter-shaft has been run down the centre of the valley. This drives a set of pulleys and the usual tensioners via several toothed belts, at the rear of the block. Being a retrofit, the belts are extraordinarily difficult to change, so with any luck the engine won't throw any. Note the riser manifold in the centre of the valley, to pick up the supercharger (see below). Also note the inlet at the top-left of the picture. |
 |
Here's a shot of the (almost) complete engine.
Alternator at the right-bottom, Sprintex supercharger at the top, coil packs
just to the left of the alternator, intake from left.
FYI, the rod just above the supercharger is the steering column, and the two blue silicon rubber lines connected to the nose of the supercharger run to a breather. |
 |
This is the front of the engine, after removal of all the plastic timing covers.
The serpertine reinforced rubber timing belt follows the red path with the crank pulley
('A') turning in a clockwise direction. The tensioner ('B') pushes against the
tensioner pulley arm and the pulley ('C') tensions the belt. Note that the tensioner
is on the trailing/slack side of the crank pulley. Other items are as follows:
|
Dry-Sump System
 |
The dry-sump system is a method of eliminating surges in the delivery of oil to the engine. When under extreme loads, an engine will not tolerate losing its oil supply for even a short period of time (we're talking less than a second here). Unfortunately the design of most sumps is geared around your average street sedan which will hardly ever encounter sufficient g-forces to result in the oil-pickup sucking air. Many types of race cars do however, and whilst some manage with oil pan baffling (it's a cheap first step), the ultimate solution is dry-sumping. The system simply moves the oil out of the existing sump into a remote tank (pictured below), via scavenging pumps running under the block. A seperate pump then takes oil from the remote tank and pushes it into the engine. The remote tanks are usually vertical cylinders to remove all likelyhood of surges occuring. Pictured is the (rather dirty) 3-stage dry-sump pump that's running on the Rodeo. A second advantage of the dry-sump is the ability to lower the engine, and hence lower the car's centre-of-gravity, improving handling/cornering. |
Supercharger
 |
Pictured is the
Sprintex
supercharger (fairly old version - S102) that provides about 5psi (on top of
the atmospherically provided 14.7psi) and thus (theoretically) should gain
an extra 35% power from the 3.2l motor. According to the
Sprintex calc sheet, the engine should be producing about 237kW (318HP)
@ 7500rpm. This is overdriving the blower slightly, but they reckon
it'll handle it. The nose extension can be basically run to any
length, and allows for correct pulley placement relative to the blower
position.
A. Intake. B. Nose extension. C. Drive pulley. D. Outlet. E. Breather connections. F. MAP sensor and fuel pressure regulator pickup. Note: the Sprintex supercharger only requires a small breather, until such time as the internal gearbox/rotor-chamber seal starts deteriorating. The second breather appears to be an interim measure taken to avoid a rebuild (which was quite reasonable after 10 years of racing). Having now been rebuilt, even the single 3/8" breather is a bit of overkill... |
 |
The supercharger ally riser is a custom job. Things of note are the retaining screws to stop the supercharger mounting bolts (4 of around the outlet) falling into the intake, and the crude plenum chamber. My gut feel is that the design of this plenum is somewhat suspect and that the cylinders would be better served if the air/fuel mix was delivered in a more precise manner. |
 |
This is the rear of the Sprintex supercharger.
Pictured are the rotor bearing housings and the vague outlines of the rotors
themselves. One rotor is a male and the second is a female, together
providing pressurised air to the outlet. Given a max engine speed of 7000rpm, the crank/blower pulley arrangement produces 14,000rpm and the gearing in the supercharger produces somewhere around 20,000rpm. Those things are really spinning... Not only that, but at 7500rpm, the engine is using ~250 litres of air per second, or a somewhat surprising 15,000 litres per minute. Now you know why you need a good air filter! |
