BigPapa said:
Hey fellows,
To do the drop valve method of finding TDC do I need some kind of valve spring compressor? My pin must be broken off and I had marked TDC on my balancer when I changed injectors, but when I tabbed my dowel pin I forgot about the mark on the balancer.
Thanks,
Scott
Short answer: No.
Long answer:
"Drop Valve Method" is simply taking slack out of the valve lash adjustment so that the piston and valve meet at the top of the stroke. The further you let the valve travel into the combustion chamber, the further your marks will be apart. The procedure is in the 12v service manuals. Basically, I check to make sure that I'm near TDC--by finding the point where #1 exhaust and intake valves are closed, and intake #2, exhaust #3, intake #4, and exhaust #5 valves are closed. (Find this under valve adjustment in service manual). If the opposite valves are closed (E2, I3, E4, I5, I6, E6) then the engine is "180 out". Rotate crank 360 for approximate TDC. THEN crank E1 valve lash adjustment down past zero a few turns. Then I think you rotate backwards to solid stop and then forward to solid stop, then mark the place between those stops for TDC. DON'T FORGET to re-adjust the valve lash! Otherwise you'll get a dingy in your piston and a bent valve.
Something like that anyhoo. One can also insert a feeler into the injector hole and find the position of the piston--but be careful, the combustion chamber in the piston can catch the feeler and bind it.
Have fun.
Addendum:
While we're on the topic of valves. I had a thought while working on the Red one. I measured the circumference of the harmonic dampner and divided that by three--to get 120 degree increments. I then measured this distance from TDC both ways and marked those places. The engine fires in 120 degree divisions of the crankshaft. With these marks in place it was very easy to check the valve lash in firing order as I cranked it around. 153624-from memory you might double check that.
So it went like this:
At TDC I checked 1I,1E, 2I, 3E, 4I, 5E (per manual).
Then I barred to the 120 mark and checked both valves on 5.
Then I barred to the next 120 mark and checked both valves on 3.
Then I barred to TDC and checked 2E, 3I, 4E, 5I, 6I, 6E (per manual).
Then another 120 and both on 2.
Then another 120 and both on 4.
Then TDC and double (triple) checked the first set.
You gotta go through the revolutions, why not check your work?
Junkyard type paint-marker is good to have.
Carry on.
Attention: TDR Forum Junkies 
:-{} Their rules are very simple too. 8500lbs, 26" hitch height, hanging weights allowed, safety junk *recommended* 
Ok made the name up. Not sure if he has named it or not, but it sure is purty 
I have a brand new set of Dueler A/T's on my truck, but they don't do so well in mud. I know the track is going to be a M/T tire track having the mud run the weekend before. 
At least I'll keep my points up to date with that pulling series that way. :-laf
I haven't even opened up my issue yet. I had already forgotten about sending that 100K picture in.
