Calm down fellas, I accept any and all relevant tech info on this topic. I neglected to say that the heads have already been ported and polished along with the intake to match. I do not have flow numbers from the porting but will be getting them flowed prior to and after this round of work.

Also, It was my understanding that most stayed with the 2.00/1.56 combination since machining was not required? Could just be a false rumor I heard.

Either way, I'm going to be going with the 2.02/1.60 combo and am looking to make a purchase on the valves pretty soon. The heads are off so now I'm just looking for someone to do the machine work and flow them.

 

Yours sounds like a mild combo.Any of the big name brands makes a nice valve which will give good service. An undercut valve can have a significant effect on flow, so you should get them. For really extreme uses they are not recommended because the undercutting weakens the stem. But FWIW, even on my blown + N2O setup I am using them. The undercutting also reduces weight.

Light weight is good, but extremely light valves (like sodium filled) are not necessary for a mild buildup. The LT4 used them not so much because it was high rpm (the redline was only 6,400 if I recall correctly) as because they wanted to raise the rev limit and stick with a spring that could be installed without any changes to the heads. IOW, they were using a marginal spring which needed all the help it could get.

Rich Krause

 

What is the length and diameter that I should be looking for?

Looking for 400rwhp with this combo....before I hit the button. I hear alot of good talk about the Manley's but hate to overpay for hype.

 

What exactly are you comparing here? The Manley Race Flo valves are priced very well given the other options I looked at.

 

Interesting thread...

FWIW, running even stock sized valves "without machining" isn't going to work very well. Nomatter what you do, you're going to end up paying for a valvejob - how labor intensive that is depends on what all is done.

As far as the 2.00/1.56's being wrong... think what you want, but there's no "wrong" really when talking 2.02vs.2.00/1.60vs1.56. The valves being larger than the seat can help in some ways, hurt in others, and not matter in most. Run what you want, but you'll be hardpressed to find a better valve than the Ferrea 6k 2.00/1.56 stuff in my opinion .

 

Here's a cool link to a page about some pretty trick valve springs that I bought for my LT1.

They will supposedly eliminate as much valvetrain weight as Ti valves.

 

That's pretty much what I was going to relay to you, as told to me by a reliable experienced head porter.

 

OutKast, if you haven't already bought valves, drop me a line at mlgracing@comcast.net

I have a set of Ferrea valves that you might be interested in.

 

FastZinTennessee - Comparing to some valves I've been seeing on ebay. Most say they are stainless. Take a look at the maddog valves on there and let me know what you think. I'm doing my best not to buy crappy ones yet at the same time don't really feel that I need those unobtanium supervalves either

SkarodoM - I don't think I said that the 1.56 is "wrong" but after talking to a few others I'm now starting to get the idea that there is little to no difference between going with the 2.00/1.56 vs 2.02/1.60

 

I was referring to ameanTA's comment regarding valve size . The difference on whether i'd run one or another would be more an issue of longevity vs. performance than anything.

 

Sorry, didn't have the energy to read back and see if it was me that said it

Longevity Vs. Performance - Can you elaborate a little on this? Are you saying that the 2.02/1.60 will give better performance than the 2.00/1.56 yet the 2.02/1.60 will "wear out?"

Thanks

 

I read that article, those look trick as valve springs look trick as hell, its too bad I just laid down the long jack on some dual coils.

Aaron