cam timing and burn - PeachParts Mercedes-Benz Forum

ckeefer · #1 03-23-2007, 03:48 PM

I've got a 1980 450sl. When I set the cams up, and they are 'correct' in a sense that the valves are opening and closing when they 'should', but the notch on the right side cam was about 180 out from the mark on the carrier/tower. The left cam was directly on the mark. Now, I've got a decent idle but no power, drives like a vw bus. I pulled the plugs, compression test says 185 +- 5 psi across the board. On the plugs, all the right side plugs are looking pretty rich (even for a carbed car) while the plugs on the left are super lean, very dry and still look new, almost no sign of burn other than the fact that fuel is not present on the plugs.

I'm beginning to think that the right side cam is off by a tooth or two as the distributor is not delivering spark at the right time interval for at least one of the cams if not both. I'm guessing the best thing to do is get that thrust washer off and flip it so it matches up? I believe it had been apart and not put back the right way.

Anyone had this problem, and for the sake of the board, is there any way that someone can describe the exact way to set-up the cams considering a new timing chain? All the cam timing info I've been able to find thus far has been conflicting or uncertain.

Thanks for any help as I hope to get this running nicely asap.

david s poole · #2 03-23-2007, 04:12 PM

you will probably find that the drivers side cam is 180deg out.fortunately pistons and valves don't meet and you could probably help your power by switching 6 and 7 plug wires,but you need to pull off the sprocket and flip the washer over so that the cam timing mark and the keyway notch are on the same side as the keyway.you may need to remove rockers to make job easier.

Strife · #3 03-23-2007, 06:16 PM

Take the distributor cap off and check that the rotor points at the small notch on the body of the distributor, AND that the degree wheel is at 0 (if it isn't, rotate the engine again 360 degrees). At this point, BOTH cams should be very, very close to their zero marks on the cam towers. IF not, you got a problem...and it's amazing that nothing...uhhhh..."bad"...has happened.