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Valve Job Gone to Hell Please Help

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johnk

20+ Year Contributor
402
3
Jan 29, 2003
Worcester, Massachusetts
All was going well I just got the last few parts to finish putting my car back together. Lapped my valves and put the springs on. I just torqued down my cams and all my valves opened at once :mad: What's the deal did I do something wrong why would they all open. I bought stock replacement valves from machv so I don't understand it. Does any one know how far the valve should be sticking up out from the retainer? I'm really dumb founded right now on how this job could go so haywire someone please help me!
 
I just thought of something which way are the rockers supposed to go? I've had the thing apart for like a month before I got all the parts to put it back together. Is the end with the large cup supposed to go on the lifter or the valve stem?
 
This is why people need to take their head to a shop to do a valve job. I'm not flaming you, but That's the exact reason you're having this problem.

1. Lapping in a valve is Not a good way to do a valve job. A Proper valve job requires cutting the seat with a surdi machine and re-grinding the face of the valve with a valve grinder, to ensure both surfaces are true. There are usually pits in the valve seat/valve face with which lapping will do nothing but make those worse. Lapping a valve should not be used as part of a valve job at all.
2. Your valves have to be at a certain valve stem height for them to work. Since our lifters are hydraulic and our rockers don't have lash adjusters, you have to set the valve stem height for everything to work properly. New valves come with alot of extra material on the tip of the valve stem so you can grind them down to set the valve stem height. If the stem height is taller than spec, your valves will open just like you're describing. You have to have a valve stem micrometer and a properly setup grinder to be able to grind the tip of the valve down to set the correct height.
3. You are going to have to measure your guides to make sure they are within tolerance. If not, they are going to need to be either replaced of git with a guide liner. Putting new valves in a head isn't going to help One bit if your guides are out of spec and your seats aren't cut.
4. You're also going to need spring shims and a valvespring tension meter. You're going to have to have the valve spring at a certain installed height with a certain amount of seat pressure. To do both, you will need to shim your springs in accordance so that you retain the stock valvespring height and the stock tension. Definately something you can not do in your garage.

My advice. Do Not do anything more to your head. Take it to a cylinder head shop, and have them cut the seats, regrind the valves (you are going to need a regrind since you lapped them into your uncut seats), and install the valves the Right way. There is nothing you can do by yourself to better your situation. Doing a Valve Job is not a weekend garage thing, and requires an equipped machine shop and the know-how to do it correct.
 
WTF ... I bet your lifters are pumped up... that would hold all the valves open... just colapse them with a small pin and clean them (I used gas) then prime them with oil... problem solved....

if you have any ?'s about this my email is [email protected]
 
I got the car back together only took all night in the freezing cold :rolleyes: The problem now is the car won't stay running. I've heard that having the CAS 180 out of phase will make it not run. Is that not at all or not good? I don't have a timing light at the moment but the CAS has a nice stain from oil on the side so I replaced it the same place. Anything else it could be? I tried checking compression on the cylender that went bad to start this whole project it checked out 165 good as new.
 
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