BIG BORE 652cc 2CV engine conversion kit; compression ratio 9:1

Give your engine a new lease of life with the BIG BORE 652cc displacement kit for the Citroën 2CV.

Designed to boost your engine’s performance, this kit provides increased displacement, with a compression ratio of 9:1, to deliver greater power and torque.

Ideal for improving the performance of your 2CV, this 652cc BIG BORE kit enhances driving pleasure and allows you to harness the engine’s full potential.

The benefits of the 652cc BIG BORE kit:

• Displacement increased to 652 cm³.
• Compression ratio: 9:1.
• More power.
• More torque.
• Improved engine performance potential.

Carburettor adjustment: jet recommendations:

To achieve optimum performance, it is advisable to adjust the jets on your twin-barrel carburettor to ensure an air/fuel ratio suited to the new engine capacity.

Here are the recommended jet sizes for an initial adjustment:

For a 24/21 carburettor:

• Original primary jet: 120.
• Original secondary jet: 70.
• Recommended jets: 125 for the primary and 100 for the secondary.

For a 26/18 carburettor:

• Original primary jet: 102.
• Original secondary jet: 87.5.
• Recommended jets: 110 for the primary and 115 for the secondary.

Important: these figures are provided for guidance only. They serve as a starting point for adjusting your carburettor settings and may vary depending on your engine’s configuration.

To achieve the best possible performance, we strongly recommend having your vehicle tested on a dynamometer to check and fine-tune the carburettor settings precisely.

After fitting the kit, a running-in period of at least 2,000 kilometres is essential.

During this period:

• Do not exceed 4,000 rpm.
• Avoid heavy acceleration.
• Avoid prolonged periods at high engine speeds and excessive strain on the engine.
• Drive smoothly and follow the lubrication recommendations.

Once the running-in period is complete, your engine will gradually reach its full potential in terms of power and torque.