The MGOC Spares range includes complete reconditioned and Stage II performance engines for both the 1275cc A-Series and 1500cc Triumph-powered Midgets. All engines are built to order on an exchange basis, with the customer's original unit returned as part of the transaction. Lead times and current build availability should be confirmed with the sales team before placing an order.
1275cc Reconditioned
The standard reconditioned 1275cc engine is a fully rebuilt unit restored to factory specification. The rebuild includes a rebored block with new pistons and rings, reground crankshaft with new shell bearings throughout, new camshaft bearings, reconditioned cylinder head with recut valve seats, new valve guides and refaced or new valves, and all new gaskets and seals. The engine is supplied as a long engine, assembled block, head, sump, and timing cover, without ancillaries such as carburettors, manifolds, starter motor, dynamo or alternator, water pump, or distributor, all of which are transferred from the customer's outgoing unit to ensure the correct match to the car's specific configuration.
1275cc Engine Identification
The engine serial number prefix must be provided when ordering. This identifies which of the five home-market 1275cc variants is required and determines the correct oil filter head, breather connections, block flange thickness, and distributor drive arrangement for the rebuild.
1500cc Reconditioned
The 1500cc reconditioned engine follows the same rebuild philosophy as the 1275cc but uses entirely different components throughout, the Triumph block, crankshaft, connecting rods, pistons, cylinder head, and all internal parts are specific to the 1500 and share no commonality with the A-Series. The single-row timing chain and its separate tensioner are renewed, and the front sealing block (with its own gasket ahead of the timing cover) and the rear crankshaft seal housing (carrying a conventional lip seal) both receive new gaskets and seals during the rebuild. As with the 1275cc, the 1500 is supplied as a long engine on an exchange basis.
Stage II Performance Engines
Stage II performance engines are available for both the 1275cc and 1500cc. The Stage II specification typically includes a gas-flowed and ported cylinder head with enlarged inlet and exhaust ports and reshaped combustion chambers, a reprofiled camshaft with greater valve lift and duration, uprated valve springs to control the faster valve events, and careful balancing of the reciprocating assembly. Stage II builds can be tailored to the intended use, whether fast road, sprint, or hillclimb, and discussing specific requirements with the sales team before ordering is recommended.
Exchange Process
When a reconditioned or performance engine is supplied on exchange, an exchange deposit is applied at the point of order and refunded once the customer's original engine is received and inspected as suitable for reconditioning. Returned engines should be drained of oil and coolant, labelled clearly with the customer's name and invoice number, and packed securely for transport. Cracked, frost-damaged, or previously welded blocks may result in partial or full retention of the deposit.
Running-In
A newly reconditioned engine requires a running-in period of approximately 500 miles, during which engine speeds and loads should be varied, sustained high revs, sustained low revs, and heavy loading from cold should all be avoided. The engine oil and filter should be changed at 500 miles to remove the bedding-in particles that wear from new bearings, rings, and bores during the first hours of running.