The MGA fuel line system carries fuel from the rear-mounted tank forward to the carburettors along the right-hand side of the chassis. The line is a mix of rigid copper or steel pipe running the length of the car and short flexible hose sections at the pump and at the carburettor float chambers, where engine movement and vibration need to be absorbed.
Replacement pipe, hose and the small fittings that join the two sit under this node. Routing, support-clip placement and hose grade are all areas where the classic specification and modern replacement practice diverge, and getting them right makes the difference between a serviceable fuel line that lasts a decade and one that leaks or deteriorates within a season.
Main fuel pipe run
All MGA variants route the main fuel pipe along the right-hand side of the chassis. The pipe leaves the tank at the right-hand side, alongside the fuel gauge sender, and runs forward to the SU fuel pump mounted on the tubular chassis crossmember behind the heelboard on the same side. From the pump the pipe continues forward along the chassis to a point where a flexible hose takes it across to the carburettor float chambers.
Replacement pipe can be supplied in copper or in steel depending on restoration approach; both were used in period. Support clips and P-clips secure the pipe along the chassis at regular intervals and should be replaced alongside the pipe to prevent chafing against the chassis in service.
Flexible hose sections
Short flexible hose sections connect the rigid pipe to the pump inlet and outlet, and from the forward end of the chassis pipe to the carburettor float chambers. On pushrod cars the forward hose routes to the H.4 float chambers on the right-hand side of the engine; on the Twin Cam the carburettors sit on the opposite side of the engine, and the forward hose routing is correspondingly different. Ethanol-resistant rubber fuel hose is the standard specification for replacement on any MGA being run on modern pump fuel, since unblended natural rubber hose of the original pattern is not compatible with alcohol-content petrol and degrades rapidly if used. Hose clips, worm-drive or wire-type depending on restoration level, should be replaced alongside hose sections rather than reused.
Unions and fittings
The rigid pipe carries threaded unions at both ends where it meets the flexible hose sections or the pump body. MGA unions use the imperial BSP thread convention of the period rather than metric fittings.
Replacement unions, olives and union nuts are available as service items and should be renewed rather than reused when a pipe is being remade, since the olive compresses permanently on first fitment and will not reliably reseal if the pipe is disturbed.
Ordering considerations
For routine replacement on a car in service, flexible hose sections and their clips are the normal service items; the rigid chassis pipe is generally durable and needs replacement only on restoration or where mechanical damage has occurred. When replacing the complete pipe run as part of a chassis-off restoration, the correct pipe length and support clip spacing should be confirmed against the chassis before final bending and fitment. Cars that have been converted to run an electric in-line fuel filter, or fitted with a performance fuel pump from the Upgrades section, may carry additional flexible hose sections beyond the original specification, and the hose grade for those sections should also be confirmed as ethanol-resistant.