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Bent valve?

Old May 29, 2014 | 12:33 PM
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Default Bent valve?

Im re-assembling my heads after thoroughly cleaning them, and with the valve seals off all my valve slide in and out of the valve guides easily accept one exhaust valve. I really have to force it in, and once it gets about 25% of the way through its then easy to slide in. Same with pulling it out, it starts to come out easily, but when I get toward the end its a bitch to pull out. Even with oil on it, I have to force it and turn it to get it in and out

Sound normal or do I need to replace that valve?
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Old May 29, 2014 | 12:48 PM
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Check for a burr on the valve stem tip. Forcing it is not good for the guide.
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Old May 29, 2014 | 12:58 PM
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I don't see any burrs, only some indents along the tip you can see in this picture. I don't know if those are typically there, or if the previous owner used some pliers on it.



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Old May 29, 2014 | 12:59 PM
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Your local machine shop can check it or you can put it in a drill and spin it. A good visual inspection should show you signs of wear in only one spot on a section of the valve and not others. Alot of times the head will mushroom a bit. You can use emory cloth to clean it up. Better to do it now. Itll cost more later. New valves run about $14-18 a piece roughly.
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Old May 29, 2014 | 02:16 PM
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Took your advice, machine shop said it's not bent but the tip is a bit out of round and some sand paper around the tip should be good to clean it up.
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Old May 29, 2014 | 02:28 PM
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Roll the valve stem on a piece of glass. If it's bent, you'll know it. That's how to check push rods, too, BTW.

Most likely, there's a raised ridge around the locking groove; that's really common. Use a fine file to gently remove that ridge.

When you force it in and out of the guide, you're shaving off guide material. That's a bad thing.
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Old May 29, 2014 | 02:47 PM
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Yeah the shop told me the same thing dammit. Sure enough, I shined a flashlight down the guide and its marred up a bit... as a matter of fact several of them have some grooves so they recommended I bring them in and have them clean up the guides with a small ball hone.
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Old Jun 1, 2014 | 09:29 AM
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Originally Posted by schmendog
Yeah the shop told me the same thing dammit. Sure enough, I shined a flashlight down the guide and its marred up a bit... as a matter of fact several of them have some grooves so they recommended I bring them in and have them clean up the guides with a small ball hone.
Don't beat yourself up....proper disassembly procedure is something that a
cylinder head specialist knows and most regular gearheads don't. In most
cases, cylinder head guys are under appreciated and under payed....perhaps
why most of the GOOD ones I know are always kinda grumpy....
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