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View Full Version : Help timing a M30



Racerhoze
06-27-2007, 08:16 PM
Anyone here had to re-install a cylinder head on a m30 and had to re-time it? I did it according to the bentley, but I do not want to risk bending all my valves. So if someone could give a quick run through of how they timed it etc. My main concern is how the little holes on the cam sprocket and the crank sprocket line up. As it is now, I have them lined up in the closest position to eachother, as shown in the picture on the bentley. If this is correct, I should be up and running by this weekend!

note: I am the one in the white shirt, and that is my buddy in the blue who has tons of experience working on engines.

Racerhoze
06-27-2007, 11:08 PM
bump?

Martinator
06-27-2007, 11:18 PM
Line up the tdc timing mark on the crank hub. Then, line up the cam, & roll it back slightly allowing the chain & gear to mesh. Roll the cam back away from the tensioner just a few degrees. Once bolted up, visually inspect the timing marks & confirm that the cam hub lines up with the head/block surface (which is tilted about 15 degrees from horizontal.) Rotate the crank by hand in the direction of fire, clockwise when sighted from the front. Confirm this by knowing the tensioner on the exhaust side of motor is on the slack side of the timing chain.

Racerhoze
06-27-2007, 11:31 PM
Line up the tdc timing mark on the crank hub. Then, line up the cam, & roll it back slightly allowing the chain & gear to mesh. Roll the cam back away from the tensioner just a few degrees. Once bolted up, visually inspect the timing marks & confirm that the cam hub lines up with the head/block surface (which is tilted about 15 degrees from horizontal.) Rotate the crank by hand in the direction of fire, clockwise when sighted from the front. Confirm this by knowing the tensioner on the exhaust side of motor is on the slack side of the timing chain.

I am still a bit confused, where exactly is the cam when you say to "line up the cam." And can you tell me the orientation of this part when it is at TDC? According to the picture on the bentley. TDC is in this picture, so if I have the crank and the cam at TDC like pictured, and no slack in the chain on the guide rail side, then shouldn't that be correctly timed?
http://img.photobucket.com/albums/v236/Racerhoze/gfshgf.jpg

Martinator
06-27-2007, 11:42 PM
Looks right. Look at the end of the cam & its dimple at 6 o'clock.

Racerhoze
06-27-2007, 11:47 PM
Looks right. Look at the end of the cam & its dimple at 6 o'clock.

6 o'clock? I think mine may be a little bit closer to 530. I lined mine up with the TDC mark on the harmonic balancer. Mine looks exactly like what is in the picture, except due to the tilt of the engine it is not at 6 o'clock. If I am a link off will that risk bending valves? or will my engine just run like crap.