When overhauling the engine, it is very important that the crankshaft is within wear tolerances with 100% smooth bearing surfaces. There are few crankshafts that meet these requirements, they will have to be machined, you will have to use undersized bearings.
You can avoid this by replacing your crankshaft with a new factory crankshaft. No problem to bring it to the specialist who will have to machine it, you don't have to wait and above all you keep the original thickness of the bearing. In addition, the price difference between a machined or a new factory copy is minimal.
This new crankshaft is equipped with large direct drilling oil channels. With cross-drilled oil channels, the oil pressure is distributed in two directions, which can create a kind of foaming effect, which can prevent the constant lubrication of a standard engine. Preference is given to directly drilled oil channels where the oil is forced in one direction in order to achieve a constant full pressure.
Note: Engines up to 1965 originally used a flywheel without an O-ring seal. This crankshaft is only suitable for engines using a flywheel with O-ring seal, take it as an extra (mentioned under the Options tab) and make sure you have a suitable flywheel. Here is the list of engines to which this applies:
Type 1 1300 cc with motor code E to E 0 0004 201
Type 1 1300 cc with motor code F to F 0 741 385
Type 3 1500 cc with motor code K to K 0 040 816
Type 3 1500 cc with motor code M to M 0 000 299
Type 3 1600 cc with motor code T to T 0 210 167
Type 3 1600 cc with motor code P to P 0 000 799
Useful information from Paruzzi magazine and from our YouTube channel :
Look for more technical articles on the page Paruzzi Magazine