Jakson

iTrader: (50)

After pulling my rockers today doing a cam swap, noticed that the #3 exhaust valve looked different. After inspection, there is a cavity ground into the stem about .040 deep and it's mushroomed out some. Any ideas as to what would have caused this? The rocker is smooth, but has the witness marks of the hole.

cam

iTrader: (9)

Had this same problem on an LS1 myself. Not nearly as bad as you though and this was during a head swap so I chalked it up to crappy valves and didnt look back. curious as to why this happened though

Jakson

iTrader: (50)

Also forgot to mention these are old Patriot Stage 2 806 perimeter bolt heads with stainless 2.02/1.57's.

I'd like to know how it happened too. I had the rockers off another time when I advanced my cam, that was about 4k miles ago. I didn't notice anything out of the ordinary then, but I wasn't looking too closely being the motor only has 10k or so on it.

Mart00SS

iTrader: (19)

strange. Was the rocker dry? I'd pull the pushrod out and check that there isnt anything clogging it up that would cause the oil not be be able to come through and properly oil that rocker.

ShevrolayZ28

iTrader: (4)

A while back one of the valve manufacturers sent out a batch of valves that had insufficient hardness. The result of using these bad valves looks a lot like what your showing. I know at least some of these bad valves ended up in aftermarket LS1 heads. Might want to look into that... and take a close look at the rest of your valve tips.

trans_am7935

iTrader: (15)

the bad batch i believe you are referring too is the comp 918 beehive sprigs...they had a bad batch and they would break pre-maturely as well.

ShevrolayZ28

iTrader: (4)

No. I was referring to valve stems. I'll try to find the thread.

ShevrolayZ28

iTrader: (4)

There ya go...

https://ls1tech.com/forums/generatio...ad-owners.html

BTW the op's valve geometry appears to be good. That valve stem got peened right in the middle.

ShevrolayZ28

iTrader: (4)

But I think the failure would have happened sooner if it was a bad valve, within a 1000 miles if I'm not mistaken.

Make sure the spring isn't broken and make sure of the oil supply. Maybe something clogged the pushrod...idk

cam

iTrader: (9)

Hmm my heads weren't AFR's but the time frames coincide so likely this is what my issue was as well. Mine were the long defunct American Speed Stage 2 hand ported 853's

ShevrolayZ28

iTrader: (4)

It's quite possible the bad valves ended up on heads other than AFR. AFR was the only one, to my knowledge, that stepped up and put out a recall.

racer7088

Valve tip surface finished started going away. Might have been something weird like lack of oil but I see stuff not quite that bad with stock rockers a lot especially with more pressure or shimmed up stands. This looks like maybe something got caught in between the two or started this and then it just kept going and getting worse. I have some MUCH worse than this. Also beehives cause more valve rotation as does floating valves and then they will get round wear like that at times.

cam

iTrader: (9)

Indeed. You get what you pay for and these heads I ran worked okay but not nearly at AFR's level thats for sure. Nor was the shipping or customer service outstanding either which is likely why they are long gone now.


In my case it was only in the very center of the valves. About half were affected but I was running Duals. Are you saying this problem is more likely to happen with beehives?

racer7088

The weird hole type wear it seems sometimes does but it could also be a softness issue since the stockers basically scrape across the tip.