02WSsicks

iTrader: (6)

I lost the timing chain bolts on my 02 Z06. They backed out and took the cover, and some valves with it. I have some concerns

1. There are some nicks in the pistons from the valve contact. Will this be a problem?

2. The rocker arms LOOK good, but is there a way to measure for bends?

3. Should I replace the valves with stainless, or stay with the lighter hollow valves?

Any other advise?

This is a blown 02 Z with dual springs and hardened push rods. It looks like the valves took all the force as the push rods didn't bend. Still worried about the rockers.

parks450

iTrader: (17)

If you can find the hollow/sodium valves stick with them. As for rockers get a upgraded trunion set from tsp or something. And definately make sure the pushrods are within their
specs for straightness. The pistons should be fine as long as the niks are on the top and not on the sides, or are very deep. Just file them off lightly to smoothen them out.

ls1 1990 VN

Valves smacking standed pistons is always a concern, they will not take the hit as well as forged.
Replace with the sodium valves, much lighter on your valve train.
Goodluck.
I've been there with a broken Rollmaster chain.

02WSsicks

iTrader: (6)

I did have the upgraded trunion rockers installed, but don't know if they may have bent. They look ok? Anyone know of a way to check?

02WSsicks

iTrader: (6)

I rolled each push rod and they seem straight. Where is a good place to get the hollow valves?

vettenuts

iTrader: (4)

Not sure what you are running for a cam, but with heavy dual springs the lighter valves are not really buying you anything. I would pick up a set of standard springs and use those instead. Since you are running an A&A system, call them and see if they think you can run the standard valves.

crainholio

iTrader: (2)

Stock cast rockers don't bend, they will break first. Inspect the contact points at the pushrod and valve ends for deformities or damage.

Manley makes hollow-stem intake valves in LS1 size. I haven't found anybody making hollow sodium/potassium filled exhaust valves, though. GM ones were discontinued and are hard to come by. Exhaust valves are much smaller and therefore lighter than intake valves, though, so I'd be OK using solid ones in all but high-revving applications.

I ran stock solid LS1 valves on 14+ road course track day events, spinning 6000-6200rpms for long periods of time. Had two intake valves float during an autocross repeatedly bouncing off the 6400rpm rev limiter after 6 years of this, but the exhaust valves had no problems. This was with a TR224 cam with aggressive lobe ramp rates. If I'd kept up with my valvespring maintenance and replaced them proactively, I would not have had a problem...the Crane duals I installed in 2004 were just used up.

02WSsicks

iTrader: (6)

I switched to duals after I lost a 918, and was thankful for the rev duals when I lost one of the outers(on a stock cam).

Guess I have to search for some aftermarket stainless valves.

P.S.
Why the hell would GM stop making the hollow stem valves?

crainholio

iTrader: (2)

I just checked, and while the hollow intake valve doesn't show up in the GMPP catalog, the hollow sodium-filled exhaust valve **IS STILL THERE**!

12565312 is the sodium-filled ex valve, and it shows as available...but ~$30 wholesale price. Ouch * 8 for a complete set.

Not sure on the Manley hollow intake valve stem length, whether it's longer like the GM LS6 valve, but the weight is much lower than a solid valve so it's a good option.

vettenuts

iTrader: (4)

You can shop for solid valves as some weight less then others. The intake valves in the Dart heads I had was larger but weighed less than the stock GM valves.

One other option is some of the head shops have used sets from heads they have ported and installed larger valves. When I was looking a few years ago Livernois had a few used sets in stock.