Porsche 924 2.0 cranshaft bearing

145.00 €

Size

Clear

Crankshaft main bearing Porsche 924 2.0

Mespiecesauto has restarted the manufacture of crankshaft main bearings for the Porsche 924 2.0.

These bearings are remanufactured to original standards, complying with the SAE 794 standard (trimetal).
Compatible with all 2.0 L Porsche 924 engines (naturally aspirated, Turbo and Carrera GT) from model year 1977.

Complete set reference: 046105701
Individual references: 046105501, 046105561, 046105591 (3 bearing types make up a complete set)

Note: when buying parts for the Porsche 924, some references available on the market may have design and manufacturing defects.

To learn more about the materials and manufacturing processes, see our dedicated article.

The price shown corresponds to the complete engine set, delivered.

Technical specifications

Warning when choosing your parts for the Porsche 924: we have found that some bearing references have significant design and manufacturing defects. Here are the main points.

1) Aluminium bimetal vs Cu-Pb trimetal

Being aluminium-based bimetalthese bearings offer a load capacity initially lower than that of trimetal copper-lead alloys. This results in a reduced mechanical margin under severe use.

2) Major porosity & abnormal microhardness

The presence of major porosity (see below), confirmed by a microhardness test in the sliding layer, reveals a casting defect in the aluminium alloy. These defects reduce the strength of the substrate under loads and increase the risk of creep of the bearing.

Porosity and abnormal microhardness on Porsche 924 bearing — Major porosity in the sliding layer (supported by a microhardness test).

3) Faulty composition & bonding

Theabsence of copper in the sliding layer (see below) points to a composition non-conformity with respect to bimetal standards. Furthermore, defects revealed by dye-penetrant testing on the back of the bonding layer (photo A) suggest a problem during co-rollinggenerating a cold weld between the bonding layer and the back of the bearing. These observations imply a marked decrease in fatigue strength and an increased risk of delamination of the alloy.

Absence of copper and bonding defects on Porsche 924 bearing — Absence of copper in the sliding layer and bonding defects (dye-penetrant).

4) Pure iron backing instead of SAE 1010 steel

The demonstrated use of pure iron (below) instead ofrolled steels of the SAE 1010 type leads to a decrease in resistance to static and cyclic loads. On tightening, a yielding of the bearing shells can occur, reducing the retention of the bearing in its housing. This leads to an increased risk of rotation of the bearing around the shaft, overheating (degraded heat dissipation) and the possibility of cracking of the backing under fatigue, particularly at the support discontinuities (lubrication grooves).