m40 timing the cam pully?

[keen 6]

the cam pulley has about a tooth of movement in it this seems to be the same as the variable cam pulley. what is the best position for it ? I would guess that its best to start in the middle. and is there a big change from one side to the other?And would there be a noticeable difference.

[Silver Fox 43]

Set it to the middle, the Motronic takes over from there.

[*Glenn* 854]

Set it to the middle, the Motronic takes over from there.

Sorry Dave , thats not right. Motronic only controls ignition and injection timing. The reason the cam pulley is slotted like that is to get the valve timing correct. It allows for variation in belts and head height ( after planning )

To do it correctly you need 2 tools. A locating pin for the flywheel to lock it at TDC and a camshaft profile set tool to align the camshaft in the correct valve timing position ( firing No1 cylinder ) In the Haines manual it gives you the measurements to make these tools and how to use them to set it up. Try borrowing them or get someone to do it for you. If you get this 100% right it will idle properly and perform correctly. You can try "hit & miss"... but it wont be right. Buy the book if you are doing it...or research it. If you get the cam timing wrong buy a couple of teeth you will do serious damage to your engine.

You need to fit these tools, then adjust the timing belt tension. Remove the tools, wind the engine over by hand 2 X and recheck position & belt tension before complete assembly. These tools are needed on nearly all BMW motors wether they be belt or chain driven. There are several different variations depending on what motor you are working on.

Just a warning: If you are not sure, dont have the instructions, and dont have the skills or the right gear.... you will cock it up.

Cheers

Glenn

Just to add. Dave you should get these tools. Correct valve timing=HP gains. I can get these made up for you

[Silver Fox 43]

I have thanks Glenn.

Edited March 28, 2008 by Silver Fox