Reply to TomP-TX:
I decided to pull the pony motor and it wasn't too bad of a job once you dug all the dirt and grease away from the nuts. I removed the intake and checked the clearance between the lifter and valve stem. the exhaust had .006" and .007" but the intake had very little play, my feeler gauge only went down to .005" and it wouldn't fit. a normal piece of paper wouldn't fit but a thin receipt slip would, so I'm guessing about .001" to .002" clearance. If you look in the intake port it appears clean, you would think if the intake valve was staying open a little it would have carbon in it. Can someone tell me the spec. for the valve clearance. and if I do need to grind the valve stems how bad is it to get the valve stem keepers off. Already have all the parts. I was suprised that all of the seals and gaskets are still available from Cat. Thanks for any help.
Clearance (cold- both intake and exhaust) - .007" - .010"
Exhaust valves
Stem clearance in bushing - .003" - .005"
Max permissible clearance in busing (w/ new valve) - .007"
Valve seat angle - 45 degrees
Intake valves
Stem clearance in bushing - .0015" - .003"
Max permissible clearance in bushing (w/ new valve) - .005"
Valve seat angle - 45 degrees
The valves have stem type keepers on the lifter end. On the opposite end under the spring is a C shaped retainer with a tab on it. Pry back slightly on the spring and the retainer should be able to be pulled out easy with a pair of pliers. When the C shaped retainer is removed, the valve/spring will come out as an assembly and then can be further disassembled. Be sure to mark where all the parts went so they can be returned to the same places they originally became seated. When you re-install the valves, be sure to give them a pry from one end and a few raps with a rubber or rawhide mallet from the other to make sure the keepers are completely seated. Inspect the C shaped retainer and make sure it is completely in the slightly recessed area. Also, while you have everything removed and apart, it's a good idea to use a pressure washer to blast out all parts of the water jacket (especially the heads). I was amazed how much sediment I flushed out of mine...I guess because the pony is furthest from the water pump and due to the decreased coolant velocity, this is where all the trash settles out.