timing chain may have stretched and jumped a tooth or two, resulting in interference.
Time to pull the heads, I’d say. But, I’m interested if BC has any tricks up his sleeve for this.
Hi
We also pulled the push rod on the intake valve for cylinder #1, which is one of the two that the had crocked rocker arms with the pushed up stud. It’s bent. We checked the breakaway torque on the rocker arm nut and it was about 12 ft lbs, which according to my shop manual is within specification.
A couple questions, should you replace all the push rods or just the bent ones? Is there any reason to pull the intake, so far we haven’t , if we don’t have to that would be fine.
Here is a picture of the bent push rod as well.
Thank you
Evan
I thought I would do a quick post with a little info about the car. It has 97000 miles on it. The head with most the issues was done in 1978 at 47000 miles. due to low compression on #3 cylinder. From the bill it looks like they changed the valve, timing chain, and all gaskets. I’m not sure which valve was done the Ford part number is C6A? 6505J I think it’s hand written. The engine has never been rebuilt, it’s all original, all the numbers match for it. I don’t know if this info is important or not but I did have it available.
Thanks
Evan
Evan,
“All the studs for the loose rocker arms are pushed at least an 1/8” or more out of the head. Can these be driven back into the head, and if so will they hold?"
NO they will not hold.Once they come lose you no longer have a press fit and they will pull out again. Unfortunately, it’s time to take the top end apart… The heads will have to go to the machine shop and get the studs pressed back in and then pinned, or the better fix is to have them machined and install screw in studs. Once you get it apart check for valve to piston contact and you may even have a bent valve. This will also allow you access to the lifters, and check them as well. Let me know what you find with some pictures which are very helpful to figure out what started all your problems.
Need more info on what else you find taking it apart, but the start of it all could still be a stuck lifter. I’ve seen this happen before with a stuck lifter. Where the push tube comes out of the socket and catches on the edge of the lifter. Then on the next camshaft rotation when it comes on lift your pushing the valve open until the spring goes to coil bind (solid) then something has to give. Results in a bend push tube and pulled up rocker stub. If the valves are OK and not bent and didn’t hit the piston this is more likely what happened. Should be witness marks on the lifter from the push tube. Keep all the parts together by position when taking it apart. This will help figure out what happened and the route you need to take to fix it from not happening again.
I enjoy helping you out…This is fun stuff for me to figure out valve train failures.
Brian