I pulled my pass side head tonight to examine the #8 exhaust valve because it was leaking pressurized air during a leakdown test (could hear and feel it at tailpipe). I pulled the number 2 ex valve first (got turned around...Doh!) and it was a little hard to pull out once I got it past the seal. When I pulled the #8 ex valve it was even harder to get out and I had some metal shavings in the groove, obviously cut from the guide as I pulled the valve out.

Upon examination I noticed that the locks had created a high spot on the top edge of the keeper groove. I stopped working at that point for fearing I had already done damage. So...

Have I totally mangled those two valve guides?

How do I get the other valves out? I expect I'll have to sand down the high spots. Will this destroy the valves? Are these valves suspect anyway because they have the high spots?

BTW, I have Fast Burn heads with stock valve components.

Mine did same thing. Guy at shop doing some "upgrades" on mine ran a honing stone across them (just enough to knock ridge off) and they all slid right out

Yea...happened to me with all my valves. I took a file and went around eack stem to knock off a microscopic burr. Then they all slid out like butter. I think valve float was the culprit here.

I noticed that the stock part (lock in particular) dont fit the grove real tight. They move a litte, which just pounds the grove on the stem. Get a better set of locks retainers. The Comp 10* units I got fit the valve super tight with no slop.

Can't help you on the guide...should be OK. You just made a "oiling groove" AFAIC.

Thanks guys, and you re-used the valves with no problem?

I suspect valve float as well. On about half of the valve tips there are "asterisk" shaped sets of lines from the roller tips. I have been told that this is a sign of float. I am going to replace my springs with beehives. I suppose Comp offers 10* locks with the beehive keepers.

I am planning to get the heads surfaced and lap the valves. The #8 wasn't burned (no metal missing) but obviously wasn't sealing well.

Valve keeper damage is usually caused by too little valve spring pressure, that is the real reason for the valve floating to start with. Under no circumstances would i reuse a valve with visable damage to the stem. Replace the valves. Real good valves aren't that expensive and the damage is already there. You might get away with it but if it continue to use an already hurt part you could drop a valve and that will set you back more than a little.

I have been thinking along the same line about re-using the damaged valves. I am looking at the Manley Race-flo's. They have a 2.00 intake and a 1.56 exhaust to match what GM put in the FB's. The GM exh valve though is a 1.55. Can anyone tell me if they think that the 1.56's will just drop in? I assume that I'll have to lap the new valves into the seats.

I'd obviously like to avoid a valve job if I can. I could obviously just go get a set of the correct GM valves but they want $47 just for one valve!!

My machinist had told me you need to do a valve job when replacing valves...even if the milage is low. Kinda makes sense...they valve and the seat are "mated" together.

Yeah, I expect you're right. Although that's not what I want to hear. Too bad doing it right and doing it cheap are almost always mutually exclusive. I think what I'll do is stop by the machine shop tomorrow to get an official opinion before I dig into the heads any further. Sounds like I'll probably be into it about half of what new heads would cost by the time I am done.

don't even think about paying $47 for a valve. You could get titanium for that.

No kidding.... But if buying just one valve would save me hundreds in machine work and a new set of valves I'd write that check.

GM Parts Direct (http://www.chevelles.com/forums/www.gmpartsdirect.com) has them for $27.00 Cheapest I found.

Thanks for the link. I'll check it out. I think i'll also post a topic for opinions on aftermarket valves. Based on posts here, I'll probably be buying a full set. Have to see what the machine shop says...

Unless the valves are severely damaged you can just file off the burrs and reuse them.

Weel, my wife and my budget would sure like me to re-ues the valves. Can anyone else help with opinions or first hand experiences with re-using valves in such a case? What are the odds that a valve in this circumstance would drop?

if it was low mileage and it had ridges on the keeper grooves something unfortunate was happening. It may have been as simple as a defective OEM keeper or two. If you really want to run it file the stuff off and get a set of quality keepers.

I just noticed you're running 107 with a 4.56. What kind of RPM are you seeing? You need to make sure the springs you run are adequate and that they're installed correctly, like the height and seat pressure. Have you checked your current installed height and seat pressure? You're running that thing hard enough to have to start paying some attention to this stuff.

Personally I see the beehive deal as a marketing tool, not a tech advancement.

did you ever find out what was wrong with the leaky exhaust valve? Maybe it's a little bent? Pay close attention to how things clean up on the lapping. A few light passes and check to what is lapping and what's not. There pretty well has to be something wrong with the seat, valve or guide.

If you want to get out of this as cheap as possible look at the Competition Products catalog. They offer some real cheap stuff but have some good buys on better quality stuff too. Don't cheap out or might get an expensive lesson and have to fix it twice.

Tom:
I would estimate that it has 2-4k miles on the engine. I built it in Aug 2000 and have just driven it sporadically since then. This was the first season that I was able to run the whole points race. Keep in mind, though, that they were pretty hard miles. I made about 115 passes this season.

I have been shifting it at 6500 and passing through the traps at 5900 (for the 107 run). It is pretty well outta oomph by the time I shift. My 31" tall MT ET Drags keep the finish line RPM down.

As far as the setup on the heads goes, they were installed as setup by GM. The springs are rated very similarly to what Comp recommends for the XE284H (according to GM). I did not blueprint the heads before I installed them but I will pay attention this time.

You know, I have no intention of running this thing past 6500. From what I understand the benefit of the beehives starts somewhere around 6k. The HP and mph I gain may well be minor compared to a new set of trad. springs. I feel that if the Beehives offer better valve control up to that point for marginally more $$ then it is probably worth it. My current predicament is not a happy one and is arguably the result of insufficient springs due to quality, qualities, or age.

I haven't been back out to the garage. I want to get to the machine shop for their opinion but work has been too busy so far this week.

Harold:

If I am going to buy parts, I am going to buy quality parts. I can't afford to "do it twice", as they say. It is more a matter of deciding if I need to spend the money on valves and a valve job or not. The difference is a few hundred dollars...

I found some interesting info on the Manley website:

http://www.manleyperformance.com/mtr.html

Look at #4 in the compressive wear section. Pretty clear explanation of AFR's recent valve tip problems as posted, IMO.