: How do you find tdc on cylinder #1 using timing marks?

08-23-12, 12:32 PM
Hello all. Im doing HG on a 2001 deville dhs motor in. I have torn the motor down and Im wondering. Can I use the timing marks on the crank shaft and the valve sprockets to find TDC on cylinder #1? I have valve spockets set 90deg on all four sprockets and crank shaft and the intermediate sprocket markings are alligned vertically @ 12 o'clock on the crank and 6 o'clock on the intermediate sprocket. Is this top dead center on cylinder #1? I want be sure before I start tearing down the valve-train. Thanks

08-23-12, 04:08 PM
Sounds correct.

08-23-12, 04:17 PM
Here you go ........ with #1 cylinder at TDC on the firing stroke - all 4 valves closed.

Go by the dots on the sprockets - some of the sprockets (not sure of the year) had one or more of the stamped letters off by 90 degrees.

08-23-12, 04:44 PM
Im not sure if cylinder #1 is @ top dead center.. So if my timing marks are in the position I have stated above is that top dead center on cylinder one? or do I have to do something else? Thanks for the quick reply..

08-24-12, 09:56 AM
Your description sounds correct. When I positioned my crank and cams I was unsure also because the Right Exhaust sprocket stamp "RE" was not in the position the diagram in ALLDATA depicted. The RE stamp was at 9:00 while RI, LE & LI were all at 12:00 in relation to the cylinder head. You can not go be the stamps on the sprockets, you need to reference the alignment notches in the sprockets. When I pulled the heads, cylinder #1 was at TDC.

08-24-12, 09:58 AM
Wow, need to work on formating attachments

08-24-12, 11:19 AM