Stainless steel exhaust systems are the long-life alternative to original-specification mild steel OE pattern systems. The MGA stainless range is manufactured in 309 and 401 grade stainless steel with mirror finish silencers, produced to the same factory pattern as the original, matching routing, mounting positions, and bracket specifications, but constructed in a material that eliminates external road salt corrosion and resists the internal attack from combustion acids and condensation that shortens the life of mild steel systems. The result is a materially longer service life, a cleaner appearance through the mirror finish silencer, and a slightly crisper exhaust note. Systems are available for both pushrod cars and the Twin Cam, and carry a lifetime guarantee.
Pushrod System
The pushrod stainless system reproduces the original single-silencer specification, a single downpipe from the three-branch manifold flange, a front pipe running along the left-hand side of the chassis, a tubular silencer carried on two mounting brackets, and a tail pipe exiting to the rear. Pipe routing and diameter match the original factory specification, so the same mounting brackets and chassis attachment points used with a factory mild steel system serve the stainless system directly. It suits all three pushrod variants, 1500, 1600, and 1600 Mk II, in standard home-market specification.
Twin Cam System
The Twin Cam stainless system reproduces the factory twin-manifold specification, two downpipes from the Twin Cam's two exhaust manifolds merging into a single front pipe forward of the silencer, with a silencer and tail pipe running back along the left-hand side of the chassis. The larger pipe diameter matches the factory specification and the silencer is produced to the Twin Cam pattern rather than the pushrod type, so it is specific to the Twin Cam engine and not interchangeable with the pushrod system.
Construction & Choice
Stainless exhausts are TIG-welded at section joins and finished to a mirror polish on the silencer and visible sections, producing a brighter under-car appearance than the matt finish of a factory mild steel system, and the exhaust note is generally described as crisper and more metallic without changing the overall volume. The primary practical benefit is corrosion resistance, as road salt exposure in UK conditions does not materially affect stainless pipework and internal condensation does not attack it in the same way, the lifetime guarantee reflecting this, though hangers, clamps, and mountings remain consumable items. Concours restorations should normally use mild steel OE pattern systems to match the factory material specification and matt finish, while non-concours road use benefits from stainless, particularly for cars used in wet British conditions year-round. Mixing stainless and mild steel sections in the same system is generally avoided, as the joint between the two becomes the first failure point as corrosion products build up at the interface.
When fitting a stainless system, the manifold-to-head gasket, downpipe flange gasket, and silencer rubber mountings should be renewed, with clamp hardware matched to the system specified alongside where not supplied.
The Double S Lifetime Guarantee
MGOC Spares has worked in partnership with Double S Exhausts for over forty years, and in that time thousands of Double S systems have been supplied to MG owners across the UK and around the world, every one backed by the Double S Lifetime Guarantee. The combination of premium British stainless steel, expert hand fabrication, and decades of refinement means these systems are built to outlast the cars they are fitted to, and on the rare occasions when an issue does arise it is treated with the same care as the day the exhaust was first supplied. MGOC Spares stands behind every system supplied, not just on the day of purchase but for as long as that exhaust is on the car.