Leyland Mini Cooper 1961-On 998cc-1275cc Wildcat Exhaust Headers WILD234

Wildcat WILD234 exhaust headers (extractors) are designed for selected Leyland Mini Cooper models from 1961-on fitted with 998cc–1275cc A-series petrol engines.

WILD234 features a tuned-length 3-into-1 header design with 35mm (1⅜") primary pipes and a 51mm (2.00") outlet. The classic Mini A-series cylinder head uses three exhaust ports, with the two centre cylinders sharing the centre exhaust port. The WILD234 header configuration is designed around this arrangement to improve exhaust gas flow and scavenging for better torque, throttle response and usable engine performance.

Some cutting and welding is required during installation. The recommended exhaust manifold/header gasket is EM40.

Please check availability and current lead time before ordering.

Key Features

• Designed for selected Leyland Mini Cooper applications
• Suits selected 998cc–1275cc A-series petrol engines
• Tuned-length 3-into-1 header design
• 35mm (1⅜") primary pipes
• 51mm (2.00") outlet
• Designed to improve exhaust gas flow and scavenging
• Helps improve torque, throttle response and engine performance
• Australian-made Wildcat performance headers

Construction

• Quality mild steel construction
• Strong welded construction for durability
• Formed pipework designed for efficient exhaust gas flow
• Heat-resistant painted finish rated to approximately 600°C
• Australian manufactured by Wildcat

Additional Options

• EM40 exhaust manifold/header gasket
• Replacement manifold studs and nuts where existing hardware is worn or corroded
• High-temperature exhaust gasket sealant where appropriate
• Performance exhaust system where further exhaust flow improvement is required

Vehicle Fitment

• Make: Leyland / Mini / Cooper
• Model: Mini
• Year Range: 1961-on
• Engine Capacity: 998cc–1275cc
• Engine Family: A-series petrol
• Header Design: Tuned-length 3-into-1

Fitment Notes

• Designed for selected Leyland Mini Cooper models fitted with 998cc–1275cc A-series petrol engines
• Some cutting and welding is required during installation
• Recommended exhaust manifold/header gasket: EM40
• Older Minis may have replacement engines, modified cylinder heads, engine conversions or non-standard exhaust systems that can affect fitment
• Please confirm the engine and exhaust configuration before ordering if the vehicle has been modified
• Please check availability and current lead time before ordering.

What’s Included

• 1 x Wildcat WILD234 exhaust header / extractor assembly
• Outlet connection components as supplied

Recommended With

• EM40 exhaust manifold/header gasket
• Replacement manifold studs and nuts where existing hardware is worn or corroded
• High-temperature exhaust gasket sealant where appropriate
• Quality performance exhaust system where further exhaust flow improvement is required

Why Good Headers & Exhaust Systems Matter

At 4,000 rpm, a 998cc engine theoretically draws in approximately 2,000 litres of intake air per minute and can expel around 6,000 litres of hot exhaust gas per minute at approximately 600°C. A 1275cc engine can draw in approximately 2,550 litres of intake air per minute and expel around 7,650 litres of hot exhaust gas per minute under the same theoretical conditions.

A well-designed header and exhaust system helps manage this high gas flow efficiently, reducing restriction and improving exhaust scavenging, torque, throttle response and engine performance.

Installation Tips

• Apply penetrating lubricant such as WD-40 or similar to the manifold studs, nuts and exhaust fasteners before removal
• Remove all traces of the old manifold gasket before installing the header
• Inspect the cylinder-head sealing surface, manifold studs and threads before installation
• Fit a new EM40 exhaust manifold/header gasket
• Trial-fit the header and check clearance before completing any exhaust modifications
• Cutting and welding may be required to connect the header to the existing exhaust system
• Check clearance around the engine, gearbox, driveshafts and surrounding components
• Protect the painted header surfaces during trial fitting and installation
• Check all exhaust connections for leaks after installation
• Inspect and re-tighten the header mounting hardware after the initial heat cycles

Warranty & Compliance

Wildcat headers are covered by the applicable 2-year manufacturer's warranty subject to standard warranty terms and conditions.

Correct fitment depends on the vehicle remaining compatible with the original application. Due to the age of these vehicles, engine, cylinder-head and exhaust modifications should be checked before installation.

FAQ

Which Mini models does WILD234 suit?
WILD234 is designed for selected Leyland Mini and Cooper models from 1961-on fitted with applicable 998cc–1275cc A-series petrol engines.

Why is WILD234 a 3-into-1 header on a four-cylinder engine?
The classic Mini A-series cylinder head uses three exhaust ports. The two centre cylinders share a siamesed centre exhaust port, allowing the header to use a 3-into-1 configuration.

What size are the WILD234 header pipes?
WILD234 uses 35mm (1⅜") primary pipes with a 51mm (2.00") outlet.

Is cutting or welding required?
Yes. Some cutting and welding is required during installation to connect the header to the exhaust system.

Which exhaust gasket is required?
The recommended exhaust manifold/header gasket is EM40.

What finish is used on WILD234?
The headers have a heat-resistant painted finish rated to approximately 600°C.

Are WILD234 headers Australian made?
Yes. Wildcat WILD234 headers are manufactured in Australia.

Can I pick up from the store?
Yes. Pick up is available but must be pre-arranged before collection.

How much is freight?
Freight varies depending on your delivery location and where stock is available. Please contact us for freight charges before ordering. Where possible, we can arrange dispatch from the nearest available product location to help reduce freight costs and delivery times.

Do you ship to the USA?
Yes. Best Mufflers regularly ships exhaust systems and exhaust parts to customers throughout the United States.

Please note that import duties, tariffs, taxes, and customs clearance fees are not included in the product or shipping price. Once your order is processed and the applicable charges are calculated, we will send you a secure payment link to finalise the import duties and tariff charges before dispatch.

Customer Support

For phone orders, fitment advice or product enquiries, contact Best Mufflers:

Call Now: +61 2 9547 3511 Email Us

Best Mufflers
87A Planthurst Road, Carlton NSW 2218, Australia
Monday–Friday 8:00am–5:00pm by appointment
Exhaust Systems Since 1983