Mechanical timing of camshafts
 

I have an 89 560SL engine 107.967 gas. My question to the forum is this; At what point of the crankshft rotation should the camshaft timing marks line up with the slots on the cam towers. I have heard everything from 5 to 12 degrees BTDC. My engine is currently set at 0 TDC, this after a timing change change. I am thinking that I may be 1 tooth off. Good compression, but the ignition timing has to be set at 25 degrees advanced inorder for the engine to run reasonably well. Seems like I am getting a loss of power and using way too much fuel.

Ideally, both cams will be at 0 TDC on the crank. Usually the rigth side is a bit later (2 - 4 ATDC) with a new chain unless you put an offset key in there.

Make sure the correct plug is being used for timing -- if not, you will be way off.

I'm not sure how the ignition timing is set on the M119, so I can't help much there, but it souds as if something isn't being done right -- 25 BTDC is about what you want at high rpm, not at idle.

Peter

the crank is 0, the cams should be VERY close to 0, also. 1 tooth off would be more like 10-12 degrees. count the teeth and divide by 360. that'll tell how far off 1 tooth would be. good luck, chuck.