Ok guys here is my question. Which valves are better for power and reliability. The two valves in question are the GM LS6 valves (hollow stem intake and sodium filled exhaust) or Manley's "pro flow" style ? Just wondering what the best part is between these 2 choices. I'm leaning toward the GM valves but want to make sure before i purchase. Thanks for the help.

 

Manley pro flow. The stock LS6 valves are great but not on nitrous or FI (reliability) and pointless if you're running heavy duals.

LS6 valves with Beehive springs and titanium retaines make for the lightest moving mass and the best harmonic controling valvetrain. So if NA running a .600 lift cam or so, that would be my choice for racing.

 

Well i guess i should go with the Manley valves . I have been toying with the notion of spraying this engine once its in and running, i just hope the tranny will hold . Thanks for the advice !

 

I'm going to have to politely disagree with some of this. It's not pointless to attempt to have the lightest valve train. Even if you are running heavy dual springs having light valves isn't a disagvantage. High RPM stability and reduced spring wear just to name a few.

Also the sodium filled exhaust valves designed to disipate heat faster than solid valves. Robert56's worked out fine taking bottle after bottle on a 225-275 multi stage dry shot on a stock longblock. He didn't even have headers. The only thing that took it out was user error as he had messed with the tune incorrectly.

I agree that a stainless valve might be better in some situations that the LS6 light weights, but not always.

 

That is what I said, having the lightest valvetrain is a benefit, but putting heavy duals on a light valve is like putting a iron block in a vette, you scew up the whole weight distribution. Otherwise why didn't the Z06 come with duals?

If you have a stock solid stainless with PP duals for exemple and a lighter LS6 valves with the same springs, there will be 0 benefit at the rpms your average motor spins. Why? because those springs are overkill on 90% of the applications poeple use them for.
Ask 100 members here why they would prefer to use duals over a reputed beehive. The answer would be 9 out of 10 "for peace of mind". Maybe 1 will answer because the seat pressures conform to what the cam requires.

 

Didnt we see a few sodium LS6 valves come apart on the heavier dual springs a while back?

 

Good info guys keep the ball rolling. I guess i should give a little engine specifics to help with the discussion. I'm building up an LS4 block into basically an LS6. It will be bored out to 3.898 (99mm) . I plan on running a quality set of forged piston and H-beam rods (not sure which ones yet). The LS4 heads are the 243 casting and have standard ls1 valves and springs , which will be upgraded. I'm going to run a carbed manifold and ignition box from edelbrock. Still undescided on the cam and springs. I would like to have a redline around 7500rpm which works with the manifold. I'm still researching alot of parts so any help is appreciated . Thanks !

 

Unnecessary. A stock LS6 cam doesn't have the lift to require dual springs when singles are perfectly adequate. The added spring pressure would increase valvetrain, cam and lifter wear. The cost of spring manufacturing is also another factor. Then of course there's the most technichal in the sense of maintaining the lightest valve train possible like you said although I'm GM was more concerned with the cost.

I agree with that to an extent, but with the prevelance and popularity of LSK lobes this might be changing. Their extreme ramp rates necesitate such a beefy spring. Hence the production of the Patriot Gold Extremes and PRC .660 lift springs.

There's of course also the huge new trend of ginormously oversized hydraulic cams on the market. Usually requiring 7k shift point to make power every bit of valve train stability helps. Especially with crazy cams like the MS4 that are pushing dangerously close P to V clearance as is. I believe you touched on that issue also in another post. Float a valve with one of those and .

I completely agree with that statement. Especially after seeing all the comp 918 broken valve spring threads around.

There's also the question of how well do your heads flow? I'm not sure of the comparable flow gain from switching from a 2.00 to a 2.02+ intake valve. 1 cfm is about 2.2hp and every little bit helps.

If you have stockish heads and are on a budget the sodium valves would be a better application as they don't require machining, they are about the same cost as aftermarket valves, and they're lighter.

Aftermarket heads on the other hand are built for maximum performance and the price reflects that. They usually come packed with all the goodies; dual springs, SS valves, and amazing flow numbers. In an application like that of course the SS valves are a no brainer.

 

When it comes to aftermarket valves, I run Ferrea....

 

Yeah, good quality valves. The only thing I hate about them is the base thickness, way too thick. It reduces PTV and adds unnecessary weight.

 

That they are, pretty beefy which is probably why I like em so much. Ive never seen a Ferrea break but Ive seen em bent to hell and back lol.

 

I'm trying to find a reliable, lightweight valvetrain solution for a N/A 347 application.

Can I safely use lighter valves in the PRC 5.3L heads than the 2.02/1.575 valves which they came with? If lighter valves are available, what machine work would be required to properly mate them to the 5.3L heads?

The parts I was planning on using to ensure 7200-7500RPM reliability are:

- ARP rod bolts
- Caddy lifters
- LS1 Rev Kit from [not a sponsor]
- at least 3/8" x 0.080 pushrods (or maybe thicker wall if the oiling will not suffer?)
- The PRC Platinum springs which come on the 5.3L heads
- Stock rockers (because I can't afford a decent aftermarket set )

Short of the rocker arms, is there anything I'm missing, or not considering?

 

AFR sells some 2.02 hollow stem intake valves. Patrick G was talking about them and they are part number: 7230 at $42 each.

 

Ferrea has a stainless hollow stem LS1 valve and they should be a direct replacement on the intake, with a valve job required on the exhaust.

Ferrea part numbers:
Intake: F1022P - 2.02, 4.900", .3135 stem diameter
Exhaust: F1021P - 1.60, 4.915", .313 stem diameter

Don't be surprised when you see the cost!

 

Ack! Right around $39/ea. The 1022P's are 100 grams and the 1021P's are 86 grams according to: http://www.totalengineairflow.com/te...ainweights.php

It looks like a custom 1.575 could be ordered direct from Ferrea: https://ls1tech.com/forums/generation-iii-internal-engine/367990-ferrea-hollow-stem-valves-s.html

Any idea what my valves weigh (short of pulling and weighing them?)

 

Well Jason @ TSP said he'd weigh the valves last night. We'll see. I found this old post from 405_HPZ06 regarding some Z06 vs. Ferrea weights:

https://ls1tech.com/forums/showpost....2&postcount=10

 

I have no idea what yours weigh, sorry. Here's what my Dart 225's valve weigh as reference:

2.055: 4.900" - 98.4g
1.60: 4.940 - 90.3g

 

No response from Jason, but a separate response from Jon @ TSP saying he'd get it to me also.

 

No response from TSP. I weighed my valves today, but forgot the lifter & rocker arm:

2.02 Intake valve: 99g
1.575 Exhaust valve: 91g
Retainer: 11g
Total spring: 93g

Even if money was no object, I need help understanding the value of saving 5 grams on the Ferrea exhaust valve for $320, or saving 6 grams on a Manley 11362H intake valve for $375.

 

We can sell you Ferrea Hollow Stem valves at a great price. Give us a call and we will be glad to go over some options with you.