Description And Operation: Engine: Notes
The AJ27 power unit is available in 4.0 L versions, and comprises:
- An eight cylinder 90 degree 'V' configuration liquid cooled aluminum cylinder block incorporating 'Nikasil' plated cylinder bores.
- Pistons of open-ended skirt design, with two compression and one oil control ring.
- Two aluminum cylinder heads, each incorporating two camshafts.
- Four valves per cylinder.
- Aluminum valve lifters and top mounted shims.
- Variable camshaft timing of the intake camshafts - vehicles with supercharger.
- Camshaft covers manufactured from Vinylester.
- Aluminum timing cover which accommodates the crankshaft front oil seal.
- Primary and secondary chains drive the camshafts of each cylinder bank.
- An aluminum bed plate, incorporating iron main bearing supports, which accommodate the oil pump pick-up, diverter valve (if fitted) and oil filter.
- Main bearings which are grooved in the upper positions and plain in the lower positions. They are manufactured from aluminum/tin material.
- A crankshaft with undercuts and rolled fillets for extra strength.
- Fracture-split connecting rods in sintered-forged steel.
- Brackets bolted to the front of the cylinder block are used to mount all accessories.
- A single, seven ribbed V-belt drives the front end accessories on all versions of the engine.
- A second, eight ribbed V-belt drives the supercharger.
- Automatic belt tensioners - one for the front end accessory drive and one for the supercharger where fitted. Each tensioner incorporates a belt wear indicator.
- An advanced engine management system incorporating electronic throttle control.
- The unit meets the requirements of the CARB OBDII USA legislation.