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Old 06-25-2012, 01:40 PM
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Rzeppa Rzeppa is offline
Cruise Moab Chairman
Join Date: Aug 2005
Location: Kittredge CO, USA
Posts: 6,718

I am 100% sure where TDC is. Both of them - before I put the head on, I rotated the crank so the crank keyway was straight up, #1 and #6 were both at the top of their stroke, and when I pressed on the crank timing gear, it happened that the mark was directly toward the cam gear, so that made me feel pretty darn sure it was oriented for TDC on #1 firing stroke.

Then I put the cam thrust plate on the cam, and pressed the cam timing gear onto the cam. When I installed the cam, I simply made sure that the mark on the cam gear was lining up exactly with the mark on the crank gear, as per the photo above. The fact that the mark on the crank gear happened to be closest to the cam gear reassured me that everything was lined up properly.

When I put the lifters in, 7 and 9 were up and the rest were down, so I'm not going by the rockers, I'm going by the lifters.

In fact the object of this exercise was to adjust the clearances on all the valves.

I have thought this through and if the cam key way is 180 off, all I need to do is simply have that knowledge when I go to stab the distributor.

Robbie, I did go through a full 720 rotation and verified that all 12 valves open at some point in that cycle.

And I not only have the old cam but I have several lying around. That is a great idea, to simply verify that each of the 12 valves opens at the proper point in the 720 compared to the old cam. While I'm at it, I could record the point at which #1 exhaust is open to verify the opposite is where it fires.

Again, this is mainly to know the proper orientation for the distributor. I want to make sure this thing fires right up when I start it for the first time and I don't have to crank it excessively and wear out the assembly lube before it builds oil pressure.
Jeff Zepp
Kittredge CO USA
1971 & 1976 FJ40s, 1978 FJ45, 1987 FJ60
Rising Sun 4WD Club, TLCA #4063
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