Originally posted by tminer
I bent the #4 exhaust valve (4th from front on passenger head). Obviously I need to replace the valve and check the piston.
Tom,
If you insist that you have bent a valve (without seeing it, or hearing it, I am going to bet you just blew a head gasket or, as you suggested, collapsed a lifter which will cause the goofy noise from the pushrod slamming into the rocker arm every so often
), just pull the valve covers and the rocker shafts. You can pull out the pushrods and check them for straightness but leave them in there for this simple test.
You will need a dial-indicator and a magnetic base. While turning the motor by ratchet on the front bolt and the dial indicator setup on top of a pushrod, rotate the engine and note both the lift registered with each lobe and the installed height with the cam on the back of the lobe. The first test will verify if all the lobes are OK. The second test will find the collapsed lifter, if one exists.
If the cam is OK, then you can do the rest of the work with the motor in the car by pulling the top half. The only way you can check a piston is to pull a head. Stock pistons are surprisingly soft. Also note that reinstalling the heads and intake to pull the motor is a quite simple procedure (just run the bolts in. No need for fancey torque values or cleanliness, cuz they are coming off again!)
Is there any testing or measuring that I need to do to check the head (valve guide?) for damage?
Machine shops are equipped to check for leaks around valves. However if it is as bad as you think, you will see it when you pull the head...it is the other 5 cylinders that will need to have this test.
What about the cam, crank, rod and associated bearings?
Cam test is listed above. All you can do with the crank is the screwdriver test to measure thrust with the neat little dial indicator you just bought.
If its not squealing now (from a spun bearing) and you don't want to pull the motor, the only thing you can do is pull the pan and main caps to check the bottom bearing half visually...but in my opinion you are just worried about the 1-in-a-million having happened to you.
Leave the bottom end alone. If on restart, you hear a bearing squeal, well, at least the top half is OK.
Stock valve, ported iron heads with 3 angle valve job. Around 3000 miles on them. Do I just replace the valve, lap it too, or should I take it to a machinst?
You take the head(s) to a machine shop for the aforementioned leak test. You throw away any bent valves (which have now been weakened by bending) and replace them. Machine shops can also easily check valve guides.
Is the timing chain also only 3k in use?
