bullitt4110

I know beating a dead horse, but in all these discussions about the valves dropping I have not seen anything saying weather or not there has been any failures once switching to the solid stainless valves. I understand that it adds weight to the valve train, which typically you do not want. But if it greatly reduces the chance of failure it may be worth the switch if not going for all out performance. I've also heard with the solid stainless valves the valve train is not as stable above 6500 due to the added weight, any truth to this from those that have made the switch?

LS9Drew

Bro theres a good bit of locals running SS valves and reving to 7k in other LSx engines around here, don't see why the LS7 be any different. Look at the shops recommending SS to stock valves, really one sided.

Do you have stock or SS? I know you have the heads ported but cant remember what Valves you got?

And you going to the meet Friday in Fremont?

Unreal

Lots of people running 7k+ on SS valves. Just need a better spring to do it. Swapping them without a upgraded spring would lead to issues. With a good spring they will be fine.

VetteVinnie

I am running Ferrea Super Alloy along with Livernois dual springs tested and verified to .700 lift. Should be perfectly fine with my mild cam. It sees ~7K often. I'll let you know when/if it ever detonates. 15K+ miles on the springs, but only 2K on the new Phantom cam (~13K was with the Lethal cam).

No road course yet, just a couple dozen 1/4 mile passes and several spirited romps through the forest. Best so far of 10.90 @ ~130 on street tires (Nitto Invos).

Hankdawg

Would it be wrong to run the stock titanium valves on the intake side? Then change the exhaust side to the SS Valves? I mean the ones that usually drop and get torched are the exhaust valves correct?

bullitt4110

My heads only have the original WCCH port job which is just a CNC program on the exhaust side, other than valve springs my heads are all stock otherwise. At some point I'd like to send them back to Richard and have their latest CNC program done as well as adress the valves.

And no my car is actually at Jeff's right now an ill be picking it up Friday night but have a busy day on Saturday as well.

LS9Drew

Wow thats weird, no wonder you didn't make much more than that other Cai/Tune car. I'd just do the Stage 2 from Richard exactly what he recommends, this is what he does for a living. And a Cam

Oh nice bought to look super fancy after Jeffs done

Zoxxo

That's what WCCH/Richard did on mine - stock intakes, SS exhaust. Stage 2 port, valve job, new bronze guides, new Patriot springs. Labor by Abel He replaced one intake valve that he wasn't sure about. I did it for reliability, not for power. I only have about 500 miles on it at this point but it still runs the way I want and expect it to. Even better, actually.

Z//

95jersey

About 1000 miles on new top end with SS valves...knock on wood.

VetteVinnie

My intake valves are still stock. Heads are milled .030 and ported. They also have Ferrea bronze valve guides.

Pistons are now the weak link. Might consider forging them before it sees too much track time. But for the street, not worried.

Rock36

For better or worse, I had WCCH do my heads with Patriots and SS valves now that I am out of warranty, and don't have the option of extended warranties here in Germany. I also had bought my car used and can't account for how it was driven prior to my ownership, other than to say there were no outward signs of abuse and the car was stock.

I have put around 4K miles on the heads and I hit 150+ mph and go 6500+ rpm fairly regularly, but I also am pretty religious about watching my oil temps. Anyway if my engine fails specifically due to the SS valves and/or the added weight to valve train I will also post here as a precautionary tale, but again so far so good.

Maybe my car would have been just fine either way, and so far my car has only seen the drag strip. It is what it is, and in the mean time I'll be having fun.

2000FRCZ19

over 5000 miles on stock intake valves and ss exhaust valves with bronze guides. using comp springs good to .700 lift. run it to 7000 with no problems and not lacking power at all.

LS9Drew

do you have any other mods? and did it feel like you gained any? Thinking about after headers getting heads and waiting to do a Cam after we find out about the new smog laws

0Cunningham Motorsports

stage 2 port, stock ti intakes, SS exhaust, CHE guides and patriot extreme springs (been replaced once due to road course use no failure just for maintenance), 15 k miles of Pure abuse, multiple 7400 RPM pulls on the dyno, street, strip, and road course (i drive the living hell out of my car no going to lie).. all this with a .661" lift cam..... this motor rev's clean to the 7400 rpm limiter.... all these yokels saying they will valve float are completely mis-informed, set your valve springs up right and you'll be fine....

Hankdawg

Perfect that is what I will do on mine the. The car will make power no matter what, it s a 427 with bad *** heads. I want to make decent power not over the top power with the reliability. Thanks for this information just wanted to see if that combo was normal.

Zoxxo

The only other mod is a Halltech intake and beehive. It's stock otherwise with 72k miles on the bottom end.

Richard said that I'd likely feel a slightly stronger upper upper rpm range and he's right. Nothing to write home about but it's definitely there.

As I said, I wasn't out to develop more power as it's "my car" and I want to be able to drive to L.A. in it (and back) without worrying about the thing crapping out on my halfway down I-5

Z//

phxcobra

Similar experience here. E85 high compression with .660 cam, wcch milled heads yada yada with SS exhaust. No issues revving to redline on road course. We'll see how she holds up. Running manley nextel .700 springs

Michael_D

It's a bit more complicated than that, don't you think, being a professional and all......

A heavier valve will reduce redline capabilities, regardless of spring set up. It's physics, nothing personal, and not opinion based. If someone doesn't care if they loose 500 r's going with a 20 gram heavier valve, then more power to them. I however, am not willing to do that. I have missed shifts and seen 7600 rpm on my HUD before. I know the hollow stem valve is stable to that rpm.

The real issue is WHY a valve fails. If the hollow stem valve fails because it is not hitting the seat correctly, or bouncing like a slinky, the solid valve will fail under those conditions as well. Hell, the solid may fail quicker, as they are GENERALLY, not made to the same standards as a two or three piece valve. Anyone who simply believes that a valve is "better", or "stronger", or more resistant to abuse simply because it machined from a solid blank, they are delusional. The only benefit a solid stem has over a hollow stem, is if the valve and piston start bumping uglies.

The REAL reason why so many head shops recommend a solid valve, is because there are NO alternative hollow stem options available, other than OEM. These guys are good businessmen and they know that there is paranoia driving customers to their doors, and they would just shoot themselves in the foot if they told these potential customers that there was nothing wrong with the OE valves.

619grappler

Katech says one thing, WCCH says another. IMO the stainless steel valves (from what I've read) have been more reliable. I'm going with the advice of my tuner as to what to do wih heads/valves. The fact is everything can, has, and will fail. Whether its from a bad install/tune, faulty parts, lack of maintenance, mis-shifts. Nothing is "bullet-proof". My heads/cam install begins next week and I have full confidence it will last. And if it doesn't I'll just rebuild. It might sit for a while as my mod money is all gone lol but I will eventually build it again. If you don't trust the stock valves, upgrade. If you don't trust the steel valves, renew your warranty. If that's not an option and your scared it'll blow at any time sell your Z and buy a Honda. Pay to play.

Rock36

Did you know that Katech uses an inconel valve with a 7000 rpm for their Air Attack Z06 TT package?

Granted they validated that setup with a custom grind cam (specs not available), so the lift or the ramp rates could be much gentler, but they still made a heavy inconel valve spin to 7K with all their safety factors.