Product description

Intake manifold preheating is an important aspect of the Type 1, Type 3 and CT/CZ engines that is underestimated by many. The carburetor is too far from the cylinder heads to maintain a good temperature. By heating the manifold with the exhaust gases, the carburetor is kept at the right temperature, which is certainly necessary in cold weather. If there is no continuous flow, the carburetor can even freeze, resulting in very poor operation or even engine failure. The whole principle is in fact an emergency jump in order to be able to produce at low cost, which was certainly part of Volkswagen's strategy.

For the Type 3 and Type 4 engines, this problem has been well solved by installing side carburetors, which are mounted directly on the cylinder heads with as few obstacles as possible, making the manifold heating unnecessary.

Volkswagen tried to improve the system in the 60s and 70s with Type 1 engines. In 1964, the left side was closed by fitting a seal with a small flow, which in 1970 was reduced to what it was before 1964 (with an identical seal on the left and right). In 1973, the 1300 and 1600 cc engines were equipped with double preheating (two tubes per side). Type 3 engines had a different seal shape on the left and right, but otherwise the flow rate was the same. The CT/CZ engines also had the same flow rate using the same seals.