Panhard crankcase oil circulation faults (revisited)

A quick history lesson on Panhard engine failures. The front main bearing and front cylinder crankshaft big end started to develop failures, as they increased the horsepower. It was attributed to insufficient oil supply, and so the front end lubrication was revised, and the camshaft timing gears were used as a splash lubrication system and the oil drilling that provided that role under the front main bearing was removed. This modification was introduced from around the early 1960’s, and ran to the end of production in 1967.

This engine is the later type, so needs modifying back to the original oil supply route, but adding the improvements necessary to negate the other faults. The first area to tackle is the front end crankshaft oil supply, so plugging the newer oil drillings and creating a matched new one under the front main bearing housing. These will be fixed with Loctite once all the drilling has finished and the crankcase has been thoroughly cleaned.



Plugging the timing gear lubrication drilling, helps to restore the equal phasing of the front rear crankshaft oil supply, but fitting a new design of oil light piston will guarantee this. Then the oil distribution in these areas will be directly related to the oil pump performance, which is still affected by the priority needs of the cylinder head & valve gear oil supply, but at least the OEM imbalance is negated.


Later I will reduce the oil level & flow in the timing gear casing, so reduce pumping losses, and oil degradation. On examination the deposits in the slingers at the front part of the crankshaft were almost double those at the rear, which is mainly due to the oil supply being much greater to the front and also the timing gear casing is a stale oil residue trap. Once contaminated here, the particulates have no option but return via the main bearing aperture, and then be centrifuged in the front slinger and as there is no drain out of this area, the oil is never fully refreshed.

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