Growing up doesn't have to suck

[iamdub]

If memory serves, your were messing around under those valve covers not too long ago, it was rockers right? This is what always made me leery of running beehives instead of dual springs.

How many L92 owners have come on here with busted #7s or #8s over the years?

Si. Replaced rockers with new OEM and measured all 16 for different push rods for better preloads.

I had a few minutes of downtime between jobs today and did some digging. Apparently, GM had a bad batch of springs in the '02-'03 LS6s. I was always lead to believe the yellow springs were rated for a little higher seat pressure and lobe lift than the blue springs and, therefore, were the lesser common and more coveted ones. This set is from some Z06 heads I had for a past project that got dual springs. The heads had less than 30K on them and the springs were kept in a box until I did my 5.3 work two years ago. I've gone just under 19K miles, so the springs have less than 50K on 'em. My cam is similar to the '02-'04 LS6 in lift and maximum duration (exhaust side), and I'm not turning more than 6K RPM. So, the springs aren't worked any harder in my 5.3 than they would be in a stock '02+ LS6. With this revelation, I have to say that I unknowingly installed a set of defective springs, thinking I was installing the better of the OEM spring options.

I haven't really followed L92 spring failures. What's the deets on this? I'm intrigued about failures being specifically to #7 and #8.

 

[iamdub]

BRO WTF!!!!!!!!

Luck of the draw. Maybe.

I ain't mad. I stand by my previous statement that this 5.3 owes me NOTHING. It's only a hassle due to the timing. I gotta take this thing to Tampa in a month.

 

[iamdub]

Damn. So, engine swap instead of just busting the head off and swapping the valve and spring?

It's obvious the piston kissed the valve. I don't know the damage to the piston. The head has to come off anyway, so I'll inspect the piston then. I wanted to have an engine on standby in case the piston was damaged. Time is of the essence and work is poppin' right now. I'm only on TYF now to wind down mentally and shift gears from work to Tahoe mode. After catching up here, I'll get out in the shop. Garrett stopped by a few minutes ago to push the Hoe into the shop with his 4-wheeler. I'm gonna get it in the air, then roll the trailer under it to use the chainfall to offload the LC9 and have it waiting on the stand. I already have all gaskets for it en route.

Depending on time, I may drain the oil and coolant so I can get straight to removing the intake manifold and head tomorrow as soon as I get home if I don't work late. And I'm on call this weekend.

Also, if the piston is ok and I just need the head fixed (new valve, guide, etc.), then I'm gonna replace all 16 springs with what I think are the LS3 springs. IIRC, those replaced the tried-and-true blue LS6 springs. I'll pull the other head to do this cuz I already have a full set of new OEM TTY bolts and swapping the springs with a C-clamp style compressor and reinstalling the head is MUCH easier and faster than doing it in the car with one of those crappy screw-down compressors, which I'd have to buy. I'm not spending $30 (or whatever they cost) to work harder.

 

[iamdub]

That sucks!
it almost looked like the valve was still attached to the retainer, but that sideways slant... eww!

It wasn't. The tip of the valve stem was about 1/2" lower. The valve was hanging down in the cylinder, hovering just above the piston at the height the piston could push it up to. The locks were sitting near the head bolt and the retainer was pinned under the rocker with what little pressure the spring still had on it.

I don't think the stem is bent all that badly. I was able to hammer it down with some moderate taps with a 3/8" ratchet. So, it couldn't have a terrible amount of bend in it... right?

This is what gives me a ray of hope that the piston didn't experience much resistance, it caught the valve face somewhat squarely and it would just have some superficial scallops in it that I'll buff a little to remove potential stress risers and hot spots. It's not boosted or sprayed and the SCR is only 10.5:1.

Lots of finger crossing here.

 

[Just Fishing]

It wasn't. The tip of the valve stem was about 1/2" lower. The valve was hanging down in the cylinder, hovering just above the piston at the height the piston could push it up to. The locks were sitting near the head bolt and the retainer was pinned under the rocker with what little pressure the spring still had on it.

I don't think the stem is bent all that badly. I was able to hammer it down with some moderate taps with a 3/8" ratchet. So, it couldn't have a terrible amount of bend in it... right?

This is what gives me a ray of hope that the piston didn't experience much resistance, it caught the valve face somewhat squarely and it would just have some superficial scallops in it that I'll buff a little to remove potential stress risers and hot spots. It's not boosted or sprayed and the SCR is only 10.5:1.

Lots of finger crossing here.

If it works out, I have two brand new GM valves floating around here.

Knee jerk reaction to seeing a small space on my valve stem tips, can't cancel a buy it now ebay purchase!

 

[Just Fishing]

GM PN 12564338
(Looks like intake valves)
Pay shipping and they are yours!

 

[iamdub]

My thoughts too. Seems Chris could have a valve in there in an afternoon.

LOL

Work is keeping me hemmed up lately and I'm too old to burn the midnight 10W-40 these days. For experiencing a failure late Sunday night to already finding a backup engine less than 24 hours later, acquiring that engine (from 45+ mins away) less than 24 hours after that, all after work, with refresh parts for it on the way, I think I'm doing okay so far.

Once I dive into the engine bay, it'll go quickly. Everything is still new-ish and clean.

 

[iamdub]

If it works out, I have two brand new GM valves floating around here.

Knee jerk reaction to seeing a small space on my valve stem tips, can't cancel a buy it now ebay purchase!

Awesome! I haven't even looked up part numbers. But you have an exhaust valve for a 243/799?

Just looked it up: 1.550".

Oh, and valves shouldn't be floating...

 

[Just Fishing]

Awesome! I haven't even looked up part numbers. But you have an exhaust valve for a 243/799?

Just looked it up: 1.550".

Oh, and valves shouldn't be floating...

I just have the new intake valves.

Exhaust valves,
I could pull out of my original heads (799), but they are sitting outside due to lack of space.

 

[iamdub]

GM PN 12564338
(Looks like intake valves)
Pay shipping and they are yours!

Dammit! Thanks, but I just need one exhaust valve, if anything.

Wasn't it Alanis Morissette that said "...it's like two intake valves, when all you need is one exhaust... ...Isn't it ironic"