I guess I just find it curious that the damage is all around the edges of the valve tips and not where the rockers ride. All of the Pro Mag roller tips look brand new.

I put in the 1518's on myself and there was no metal hammer involved(used the crane spring compressor...was a breeze). With some of the tips being filed, that takes me back 7-8 years when the heads were done after the overheating.....because I have not been filing on them in any way.

I wished I had seen this before I bolted the heads and new gaskets down(I don't remember one being as bad in the middle picture just over a year ago).

It's not too late to abort and pull them back off.....I'd sure hate to though. My plan was to use this as a backup engine and put together a stroker in the next year or two. However, it may be a wise move to get the valves replaced.

 

That clearly exhibits not having the right length push rod. Rolling way past center in both directions.

You need to understand where the rocker should be in relation to the valve stem

http://www.compcams.com/Technical/FAQ/FAQPushrods.asp

Why are you (we) still having to deal with this issue 2 years later?

 

Well Speedy, you need to talk to Chevy about that one. That picture is of the stock valve spring and retainer just after I pulled the stock rocker off it. You need to direct your complaint to the GM engineers and tell them that the LT1 stock 7.2" pushrods are wrong.

 

I'm no engine builder, but - first pic doesn't bother me. Second one bothers me a bit. Third one no way I'd run it without resurfacing.

 

After the discussion on the soft guides, I'm betting you are correct. The only other thing I could think of would be the stamped steel rockers themselves. If they had some type of galling on the tips(like on the edges of the contact stroke)....and then at high rpm(stock redline of 5700...stock stuff saw no higher than that....)...that galling was contacting the edges of the rockers...that might do something.

I think I have them stored and numbered by cylinder in gallon ziplock bags. I don't have them isolated to intake and exhaust, but I did do that to the roller rockers, comp pushrods, new lifters and such. For kicks and thrills, I'll take a shot of the roller rocker that was riding on the worst looking one. If I find anything of interest on the stamped rockers, I'll post that up too.

My point to all this is if the damage was done 8 years ago, there is really no need to change it now just for a "backup" engine. I mean, I've been riding with it that long....and it's not even a daily driver anymore. However, metal fatigue damage I would need to do something.....I wouldn't want to chance a tip blowing apart if the metal itself is coming apart due to something other than a moron hitting the valve tips with a steel hammer.

 

How possible is to roll 'way past center' in both directions with any sort of streetable cam? I sincerely doubt this is a case of the wrong size pushrods......

 

That's not from hitting the valves with a hammer, I have done that too many times to count when removing seized valves from rusty motors.

Most likely it's a combination of a few things, one being a break down in the lubrication of the tip(water, fuel in oil), valve float, and cheap valves. It's not uncommon to see that on factory valves when pulled. The metal has fatigued and the hardness is going away. I would not even resurface or tip those valves, I will always replace them without question.

 

Guess what? All of them, with damaged edges, are exhaust valves. There are 3 of them like that....not even one of the intake valves has that damage(not that I saw with my quick look). Are the exhaust valves harder than the intakes? Also, do the valves tend to rotate over time?

 

I've found a picture from 8/2008 when I was first putting on the rockers and that worst one(number 6 exhaust) is sitting in the exact position as it was 2 years ago(the car has been sitting for 1 year).

Can I rotate the valve so that the damage is on the intake side of the head? The 1.6 rockers tend to ride towards the exhaust side. Will I hurt the sealing of the valve doing this?

 

valves rotate all the time, very quickly

 

Aye.

I went out and compared my old picture to the other valve positions. Number 6 exhaust just happened to be in the same relative spot in my picture...all the others had moved. The good news is that the chips are the same size as my 2 year old picture. They don't seem to be getting any worse(for the moment). I also checked my stock rockers. I did have the good sense to isolate the valve train components to cylinder intake and exhaust bags. The stock number six exhaust rocker was clean. Looked to be in excellent condition(for a stamped rocker with 100K...no galling or any nonsense of the like...perfectly smooth tip).

 

It is galling, particularly due to the rough pitting, hammer blow would not do that. Also since it is on all exhaust valves (run hotter) and you had overheating, head warpage. Did you see anything on the old stamped rockers? There should be galling there as well.

 

I checked the stock number 6 exhaust rocker....it looks really good, no galling at all. I'll get a picture of it.

I do have another set of LT1 heads here with the valves(bought for porting)......I'm guessing it would not be a good idea to swap a couple of good exhaust valves from those heads into my current heads.

 

Galling is a metal transfer from one surface to another. You're thinking of spalling... http://en.wikipedia.org/wiki/Spall

 

220, 221, whatever it takes...