Exhaust Manifold Header Kit for MG Midget (1975-1979) 1.5L

High-Flow Exhaust Manifold Header Kit for 1975-1979 MG Midget

Replaces the restrictive factory cast iron exhaust manifold to improve exhaust scavenging and lower engine bay temperatures.

The Stock Midget Exhaust Bottleneck

The factory 1.5L Triumph engine in the late-model MG Midget suffers significantly from a heavy, restrictive cast iron exhaust manifold. This OEM design prioritizes mass production over airflow efficiency, leading to severe exhaust gas backpressure and excessive heat soak within the cramped engine bay. The original cast manifold creates turbulent collisions between exhaust pulses, preventing efficient cylinder scavenging. Over decades of continuous heat cycling, these aging cast units are also highly prone to hairline cracking at the collector and exhaust gasket blowouts, further robbing the Standard SC 1.5L engine of its limited horsepower and dulling overall throttle response.

The Engineering Solution

This upgraded 4-to-1 exhaust header resolves the inherent restrictions of the factory casting through optimized tubular flow dynamics. Featuring a 1.25-inch primary inlet stepping up to a 2.00-inch collector outlet, the continuous piping design promotes high-velocity exhaust scavenging, effectively pulling spent gases from the combustion chamber. Constructed from corrosion-resistant stainless steel, the assembly utilizes thick CNC-machined flanges combined with robust TIG and MIG welding to ensure a warp-free, leak-proof seal against the cylinder head. The elimination of internal exhaust turbulence significantly reduces backpressure, translating to reliable gains of 5 to 10 horsepower and improved mid-range torque. By shedding the immense thermal mass of the OEM iron manifold, radiant under-hood temperatures decrease rapidly, protecting nearby vintage electronics and carburetor components.

Technical Specifications

Compatibility

• 1975 MG Midget 1.5L
• 1976 MG Midget 1.5L
• 1977 MG Midget 1.5L
• 1978 MG Midget 1.5L
• 1979 MG Midget 1.5L

The MG Performance Standard

Upgrading the exhaust on your classic British roadster restores the raw, mechanical driving experience it was engineered for. By optimizing exhaust gas velocity, you achieve a sharper throttle curve and a deeply resonant vintage exhaust note.

Common Questions

Will this exhaust header fit my 1975-1979 MG Midget 1.5L?
Yes, this 4-to-1 exhaust manifold header kit is designed specifically for the 1975-1979 MG Midget 1500 (GAN6 chassis) with the 1.5L (1493cc) Triumph inline-4 engine.

Does this fit earlier MG Midget models?
This header is built exclusively for the 1975-1979 MG Midget 1500 equipped with the 1.5L (1493cc) Triumph engine.

What are the piping dimensions and materials of this header?
It is constructed from corrosion-resistant stainless steel with TIG and MIG welds, thick CNC-machined flanges, a 1.25-inch primary inlet, and a 2.00-inch collector outlet.

What kind of performance gains can I expect over the stock cast iron manifold?
Replacing the restrictive factory cast iron manifold reduces exhaust backpressure and under-hood heat soak, delivering gains of 5 to 10 horsepower along with improved mid-range torque.

How does this upgrade help with engine bay heat?
Removing the heavy factory cast iron manifold eliminates significant thermal mass, allowing radiant under-hood temperatures to drop faster and helping protect nearby carburetor and electrical components.