MGA Engine Restoration

MGA cylinder block with cracked head

Southern Engines have recently been asked if they could save an old 1600 MGA Engine block.
The MGA engine block had been in a garden for many years and the owner decided he wanted to rebuild the engine for his MGA car and keep the one he removes for a spare.

The engine in the garden was so rusty that he spent weeks smashing the seized pistons out of the rusty cylinder bores. When he finally removed the pistons he noticed he had broken the MG s cylinder walls through to the water jacket on one cylinder bore and cracked the other three bores.

See images on the right
Alan of Southern engines said he thought that a repair was possible and the block could have 4 cylinder liners made and fitted to the MGA engine block. The damage to the engine block in one cylinder was so bad that Alan was suprised. Because of this damage the liner needed to be extra thick or a hot spot would be created and cause possible premature failure.

The engine block was rebored out some 0.0250 thousands of an inch to accommodate the new cylinder liners. The cylinder liners are interference fit of 0.003 thou, they are pressed in to the cylinder block until they reach a step that is cut at the bottom of the bore. Alan says he always does this as security for the liner. many people take the easy option of just pushing the liner so its flat to the head face of the engine block relying on the 3 thou interference to hold it in. Southern engines choose to leave a security step so even in very hard operating conditions the liner can never slip. The cylinder block is then refaced to remove the protrusion of the liners and the job is complete.