LT1 Based Engine Tech 1993-1997 LT1/LT4 Engine Related

Chipped valve edges???? Picture....

Old Jul 27, 2008 | 01:13 AM
  #1  
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Chipped valve edges???? Picture....

I started installing the springs on the heads tonight and have run across a couple of valves that look like the following....



Call me crazy, but this can't be good. Do these valves need to be replaced? I think the stock rockers are the cause of this.....

Anyone else seen this?
Old Jul 27, 2008 | 07:33 AM
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just use them, your paranoid
Old Jul 27, 2008 | 08:04 AM
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I agree, I would 'rather" them not be there but there is no problem using them. If you ever pull the heads and remove the valves, use a flat file against the stems and remove the sharp edges from valve tip and where locks ride on valve befoire pulling through the valve guides to keep from scratching the guides.

Lloyd
Old Jul 27, 2008 | 01:07 PM
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Originally Posted by mdacton
just use them, your paranoid
LOL!!!! Yeah you are right. I've read about doing this for months and when I see something abnormal I go hmmmm.....

I didn't know if this was a sign that the valve tip was fatiguing in the metal somehow......especially with it pitted like that......

I feel better about it using rockers with guide plates, but if I was using self aligning, I'd be a little nervous.
Old Jul 27, 2008 | 01:08 PM
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Originally Posted by NightTrain66
I agree, I would 'rather" them not be there but there is no problem using them. If you ever pull the heads and remove the valves, use a flat file against the stems and remove the sharp edges from valve tip and where locks ride on valve befoire pulling through the valve guides to keep from scratching the guides.

Lloyd
Will do, thanks for the input!
Old Jul 28, 2010 | 10:52 PM
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Guys,

I'm coming back to this after quite a while, because I'm going back together with it after more than a year of the initial thread creation. These below are my worst ones.....




Now, look at this valve...it's been filed....


Now, about 7 or 8 years ago, the heads were pulled and milled because of head warpage due to overheating. I've been hung up on the chip damage, because I thought it was the metal coming apart due to wear and age. Now I don't think so.....

Could this edge damage have come from when the shop removed the valves for the milling? Did those jokers punch the valves out without filing and caused the edges to chip as they were rammed out the valve guides?

The good news is that I've been running the pro mags for about a year and the roller tips show no strange wear at all.

Any opinions on my theory? What happens to a valve tip if not filed and is rammed out the guide?
Old Jul 29, 2010 | 03:25 AM
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ace,

i'm like you, dont like the looks of those tips.. almost looks like they had a burr on them and whomever pounded them through the guides and broke the edges of the valve.. maybe with heat build up on the tip, and then whomever pounding them through the guide you get the chipping... then theres the question, if they pounded the valves out, what did they do with the guides?

i know from other posts you are pretty meticulous in your assemblies and things.. i'm guessing those are stock valves? you might look into a set of replacement valves..

i've been thinking about a set of replacement valves for a set of heads i'm working on myself, it'll be a while before i get to them though.

i have a friend that runs late models, he told me to check on some elgin 1.94 and 1.5 stainless undercut valves, some class they run they have to use stock castings, he said the elgin stuff will take a beating and hold up, so its gotta be decent stuff..
to my suprise the elgin stainless undercut valves were like $80 for a complete set and would be a good upgrade from stock valves i think, i know they have to improve flow with the undercut stems, plus they'll be a tad lighter which is another plus..

to add: if you go look at a new set of vavles generally they'll have a pretty heavy chamfer ground on the tip..

Last edited by brucer; Jul 29, 2010 at 04:24 AM.
Old Jul 29, 2010 | 06:30 AM
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I doubt that came from pounding them through the guides...the guides are much softer than the valves and you would have serious damage to them...and the resultant noise and oil control issues. I don't know what could have caused that damage aside from a manufacturing defect that 'uncovered over time. I guess I agree with some of the others, if it isn't in the swept area of the tip then it'll probably be fine. If you ever have the heads off again, I'd replace them....
Old Jul 29, 2010 | 07:10 AM
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when you got your heads milled did they do any kind of valve job or at the very least lap the valves? How did the rest of the valve look?

I worked for a shop for a while and never did I have to use hammers on a valve. Even bent valves could be pulled out by hand.


The valves look like they have casting defects. I don't know about stock chevy valves but if they are case hardened I wouldn't file on them too much.
Old Jul 29, 2010 | 09:18 AM
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most of it looks like galling to me. GM went to the roller style in the LT4 primarily to prevent galling from the stamped LT1 rocker at high rpm (+6000).
Old Jul 29, 2010 | 11:36 AM
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I would have changed them back in 2008!!!!!!!!!!! What happens to the engine IF the tip breaks off???
Old Jul 29, 2010 | 11:59 AM
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I guess my thoughts are that if they worry you that much..it is worth changing them for just the peace of mind.
Old Jul 29, 2010 | 12:54 PM
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I bet that whoever removed the springs rapped on them with a steel hammer to break the valve locks loose.
Old Jul 29, 2010 | 06:38 PM
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valve float can bang up the valve tips too. Float is a common problem often dismissed as something else.
Old Jul 29, 2010 | 06:52 PM
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in an ideal situation the roller should not be contacting any area that is chipped, i would not be worried about that. if i had to guess i would say it was caused by hitting them with a steel hammer to free the locks like stated before

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