The lower engine on the Rover 3528cc V8 comprises the sand-cast aluminium cylinder block with cast-iron dry cylinder liners, the forged-steel crankshaft running on five main bearings, the connecting rods and pistons, the central camshaft running directly in the block, and the timing chain that drives the camshaft from the crankshaft nose. The block has provision for an engine-driven mechanical fuel pump on the right-hand side and the distributor at the front of the V.
Cylinder Block and Liners
The V8 cylinder block is sand-cast in aluminium alloy with cast-iron dry liners pressed into the block. Bore is 88.9mm and stroke 71.1mm, giving a swept capacity of 3528cc. The block is identified by its casting marks and the engine number stamped on a plate at the rear of the block on the left-hand side near the bellhousing flange. Compared with later Rover V8 variants, the MGB GT V8 block uses MG-specific main bearings and a specific camshaft position relative to the timing case.
Crankshaft and Main Bearings
The forged-steel crankshaft runs on five main bearings. Main and big-end bearings are available in standard and undersize specifications for reconditioning. The crankshaft is balanced as part of the factory build, and any rebuild involving rotating components should be re-balanced after machining. The crankshaft pulley drives the water pump and alternator via a single belt and carries the timing marks used to set ignition timing with a stroboscopic light.
Pistons, Rings and Connecting Rods
Pistons fitted to the MGB GT V8 are MG-specific items with cast-aluminium construction, designed for the V8's 8.25:1 compression ratio. Standard, oversize and undersize pistons are available for reconditioning. Piston rings comprise compression and oil-control rings; full ring sets are available for in-situ ring replacement on engines where the bores remain serviceable. Connecting rods are forged steel with bushed small-ends and are normally re-used during reconditioning subject to inspection.
Camshaft and Timing
The camshaft runs directly in the cylinder block (the V8 has no separate cam bearing carriers) and drives the hydraulic tappets via a flat-faced cam profile. The camshaft is driven by a duplex chain from the crankshaft nose, with timing gears and chain available for renewal. The camshaft profile fitted to the factory MGB GT V8 differs from later Rover variants, and care should be taken to specify the correct cam when ordering. The distributor drive gear at the rear of the camshaft is also of an early pattern, distinct from the later SD1 drive gear, the distinction matters when fitting electronic ignition or replacement distributors.
Front Cover and Drive
The aluminium front cover encloses the timing chain area and carries the water pump mounting (the water pump bolts directly to the front cover rather than to the block). Front cover gaskets and oil seals are renewed as a matter of course during any timing chain or water pump work.
MGOC Spares
MGOC Spares carries the full range of lower engine components for the MGB GT V8, crankshafts and bearings, pistons and rings, cylinder liners, camshaft and timing chain components, and front cover items, supporting both reconditioning of original factory engines and verified-specification rebuilds.