I have just completed a full rebuild on my engine and thought i would add a few reccomendations, after a bit of a waffle.

The bmw enginge was designed as a more simple engine, with a very robust cam chain design.
After a number of years they decided to do a cost saving exercise and used a much cheaper design, very poorly thought out and prone to failure. Dont get me wrong it does work, for a while, but when it fails.......

Several parts are prone to wear and failure.

First the chain, its a roller chain but the pins on it are very small, this leads to premature wear. Incidentally a number of other manufacturers used this chain and all had similar failure problems.

The chain runs against a guide in the centre of the v, not surprisingly this fails, sometimes quickly, and trashes the whole engine sometimes too mostly by blocking the oil pump pickup, or by spreading metal fillings through the whole engine.

I did not like this idea so i decided to modify it in my rebuild.

The original design will not work as there is no space behind the front cover of a vanos engine, because of a water feed to the alternator, but you can hybridise, in true landrover tradition.

It involves

a differant chain with bigger pins to make it much stronger, and more importantly it has a much larger wear surface so wears much slower.

Using the chain centre sprocket and guides off the m60 engine, except tensioner guide, 3 in total. they do need modifying, shaving 7-8mm off the mounting lugs, prefferably in a milling machine to keep them true, but they all bolt up to the block with no block modifications. You could just use the two middle ones, but the one on the outer v thats is not a tensioner is plastic, and it breaks in use.

There is a small orifice behind the u shape guide that is no longer required, i drilled tapped and inserted a grub screw to block it. This is an air bleed for the oil, strange really in the u guide i assume it also lubes the plastic guide. Anyway not needed any more so i thought better to improve oil feed to vanos etc. It should also stop oil draining from top end whilst stood, therefore reduce wear of the top end, and rattle, on start up.

Finally you need to remove a few of the gussets on the front cover where the centre sprocket sits. I ground mine away, but you could use a mill to do it, if fact that would be better. You just need to remove the webs just above the crank sprocket hole. The alternative would be to alter the centre sprocket to a single sprocket and shorten its shaft. Easily done, but not quite as easy as removing the webs. I did consider driving this from the crank too, but that might introduce slap in the side of the main chain that above it. The front cover is strong there and nothing mounts off it where the webs are removed.

All in all an easy mod to do if you are doing the chains anyway. And you end up with a fundamentally better cam chain, and a better camchain design with no fundamental weaknesses. All using bmw parts. Except the improved chain, which comes from the same high quality manufacturer, you can of course use the same type of chain as bmw but it will not last as long. Do not ever use a cheaper chain manufacturer.

This new design should last a lot longer in best circumstances, and even in worst. But in worst circumstances, ie little or no oil, it will not shatter parts of the tensioner system and fill the whole engine with plastic and aluminium. So all in all a win win. Of course with little or no oil your engine will seize when your aluminium pistons pickup in the aluminium bores because the oil injectors there stop flowing.

I also reccomend doing a vanos rebuild at the same time, it is very easy.

If anyone wants to get more details pm me.

To those of you who believe stock systems should not be modified, each to his own, i understand the point of view, just dont follow it.

Finally if you live near me i do have all the tools to do engine and gearbox rebuilds........