LS3 hollow stem valves and big cam?
#1
LS3 hollow stem valves and big cam?
Will a Ls3 hollow stem valve turned down to a 2.04" in my tfs215 heads be OK with my cam? Its a 239/244 .674/.653 111+4 Martin Smallwood spec cam. Has .700 PAC springs shimmed. I was just worried about the valve possibly ciming apart with such a big camshaft.My FRC made 468/415 on the dyno with 500 miles on it. Last time to the track it went 10.78@129.64. It has a few thousand miles on it now. Just looking for a little more out if it.
#2
I get my stuff done in MI, the guy I go to does a lot of CNC LS3 stuff as well as some testing for GM and he tells me stay away from them in everything but mild combos.
I usually supply my own valves so it's not like he's selling me anything.
They usually take them out & use Ferrea or Manley stuff which also flow better.
I usually supply my own valves so it's not like he's selling me anything.
They usually take them out & use Ferrea or Manley stuff which also flow better.
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#10
TECH Addict
I get my stuff done in MI, the guy I go to does a lot of CNC LS3 stuff as well as some testing for GM and he tells me stay away from them in everything but mild combos.
I usually supply my own valves so it's not like he's selling me anything.
They usually take them out & use Ferrea or Manley stuff which also flow better.
I usually supply my own valves so it's not like he's selling me anything.
They usually take them out & use Ferrea or Manley stuff which also flow better.
There's no recall of the ls3 intake valve. And there's LOTS of happy ls3 owners driving their cars everyday with the stock valves... Quite a few of those happy stock valve using ls3 owners are boosted, as well... And more than one of them are beyond what could be considered a mild build, for sure.
I would run turned down ls3 hollow stems in a heartbeat.
#11
Ive seen guys on other forums say the tips came off of LS3s & a few say the heads came off which would make me believe they're a 2 piece welded valve like the LS6s but the internet experts seem to like to blame the springs.
LS6 & LS7 had issues so GM couldn't get it right on the top of the live Corvettes but did on the LS3s?
You guys have more faith in GM than I do, I've been offered them for free & didn't want them.
IIRC aftermarket hollow stems are 1 piece stainless steel & nobody can argue they're not better or flow better.
So how much do you save by the time you buy LS3s & get them cut down compared to buying Ferreas?
LS6 & LS7 had issues so GM couldn't get it right on the top of the live Corvettes but did on the LS3s?
You guys have more faith in GM than I do, I've been offered them for free & didn't want them.
IIRC aftermarket hollow stems are 1 piece stainless steel & nobody can argue they're not better or flow better.
So how much do you save by the time you buy LS3s & get them cut down compared to buying Ferreas?
#12
Moderator
iTrader: (20)
Well, I havent personally seen an LS3 valve fail, but the stock valves aren't designed for some of the abuse people put on their engines so it should be no surprise to see some instances of failed valves. It doesn't mean it's a bad valve, you just can't be a dumbass and set them up with really stuff springs and stupid aggressive lobes then expect to turn 8,000 RPM everyday on your way to work.
#14
TECH Addict
9 times out of 10, it's the Indian, not the arrow.
GM did well designing those valves and they work perfectly for their intended purpose. As previously mentioned, it is no fault of the valves when someone pushes them beyond their original intent.
Oem parts that happen to survive when pushed hard in performance applications are relatively rare. It's why these 900hp junkyard 4.8 builds get so much attention. Because it shouldn't work, but it does. However, nobody judges the 4.8 as a poor design when 30# of boost scatters pieces of the engine all over.
GM did well designing those valves and they work perfectly for their intended purpose. As previously mentioned, it is no fault of the valves when someone pushes them beyond their original intent.
Oem parts that happen to survive when pushed hard in performance applications are relatively rare. It's why these 900hp junkyard 4.8 builds get so much attention. Because it shouldn't work, but it does. However, nobody judges the 4.8 as a poor design when 30# of boost scatters pieces of the engine all over.
#20
11 Second Club
iTrader: (1)
I've been wondering myself. I have a set of L92 heads for a iron 6.2 build. I plan on replacing the intake valves because one is slightly bent. Not sure if I should pick up GM LS3 intake valves, or go with Manley or Ferrea valves. I'm unsure of the mileage on the heads so I'm wondering if I should replace exhaust valves too. I have a BTR stage IV LS3 cam kit with .660 dual spring kit with titanium retainers.