Originally Posted by C_Williams@RPM

For everyone's information or data banks - we've been running the che guide/solid stem/proper spring rate in this Corvette Challenge Series for over 4 years- and on at least half a dozen vehicles - and that includes the last three championship cars in the series. Combined, that's a lot of laps.

We've aslo gathered data on engine acceleration rates from our chassis dyno and see zero difference - acceleration ramps were run at release points of 300 RPM per second.

Originally Posted by Rock36

Great videos DH, and I'm glad you are happy with the results. I can't wait to cross over from drag racing into actual road tracks. If I wasn't on the other side of the world, I'd hit you up for some driving tutelage.

Originally Posted by Dirty Howie

Well I promised I would give some feedback after getting in my first track day with my reworked WCCH LS7 heads (guides, dual springs and SS valves)

I am very familiar with the track (Auto Club Speedway in Fontana California). I was hoping to give accurate data feedback. The weather didn't completely cooperate. There was huge wind on the track which no one can ever remember occurring before.

Anyways I can tell everyone that the dual springs and SS valves do not rev slower than stock (at least not perceptible to me). In fact I think they may rev quicker as I hit limiter 2-3 in 2nd and 3rd times today which I hardly ever do. The wind was blowing very hard across the high speed straight which made it a little uncomfortable and certainly inhibited top speed. But I did gut it out for the Forum and made sure the car would still get up to 156 mph down the straight before going into Nascar turn 1.

So bottom line is wether on the street or track there is NO PENALTY running SS valves and dual springs

Here is video of the day:






DH

Originally Posted by '06 Quicksilver Z06

I recall something about redline "slaughter".

Damn. I guess Howie forgot to take his calculator with him.

And after I told to be sure that he did, before he went out there.

Originally Posted by Michael_D

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.

Originally Posted by Michael_D

No, that is not what I have said. I said that redline capabilities will be reduced when adding weight. I'm a bit vexed that some of you are arguing with me over that point....

Just for a tidbit of info, David Vizard's latest head porting book does have a side bar on post spin tron analysis on valve weight and rpm capabilities. Three valves with the same spring, retainers and locks. 119 Gr solid stem - 7600 rpm. 101 Gr hollow stem - 8000 rpm. 89 Gr Ti - 8300 rpm.

Originally Posted by Michael_D

Now I’m pissed, at you. Just to be clear on that point.

Originally Posted by Michael_D

If I would have at that time known that the people making cavalier statements as if they were factual in regards to IC engine theory really didn’t have a clue, I would have chosen my words differently. My mistake, I own it. The point being made during that conversation was; that the addition of 20 grams of weight to this particular valve, with all else remaining the same, would result in a dramatic loss of peak rpm. I ran the calcs before, it was in the order of 500 rpm. That to me, with consideration to the peak operating rpm of this engine (7000) is in my opinion, a slaughter.

Is that better?

I have also made these posts that I took crap for stating, which you conveniently overlooked.

Originally Posted by Mark200X

That may be true but it would
a) fall into the category of uninformed speculation, and
b) I'd still like to see the posts.
I see a lot of stuff claimed that turns out to be internet myth... I heard it, I read it, somebody told me, somebody told someone that told me, but when you go look for the original source you can't find it -- often because it does not exist or it does not exist in the form it has morphed into. Unfortunately that's just the nature of word-of-mouth information; it is no one's fault, except those trying to exploit it.

Anyway, don't mean to hijack the thread, just trying to sort out some of the oft-repeated speculation and myth. I'm glad you're back on the track and the car is running good. Wish I could be out there running with ya... maybe one day not too far distant

Originally Posted by 04_Z06_CE

Thanks for info DH, I will be redoing my heads at the end of this year as well. I find it sad that we have to but I guess peice of mind is what we live for.

Originally Posted by Dirty Howie

Thanks, car ran flawlessly.

I don't really have a need to go back and find the post where this theory was expoused ............ because I know for a fact it was !!

Purpose of this thread was to dispell that information as incorrect, at least for me.


DH

Originally Posted by Michael_D

Feel free to blame me, or to call me out. I can distinctly remember a thread about a year ago where the collective CF brain trust of keyboard jockeys who have gained decades of engine building experience vicariously through the written word of others on the internet gave me a bunch of crap for a comment I made.

The comments I made was, “Redline CAPABILITIES will be reduced with a heavier valve”.

Of course a few CF valve train engineers took exception to that statement and posted brilliant arguments in an attempt to disprove simple physics 101 crap.

This GM High Tech article you continue to speak of that has done so much damage to the credibility of solid stemmed valve usage is actually a pretty damn good article, IF you actually read it with the intent to learn something. It is a very good, real world, actual test that clearly illustrates why choosing the correct spring for the intended application is so important. Or, you could simply ignore this, call it “nonsense” or a “myth” and take the advice from others on internet forums.

This moronic argument over peak rpm has gone on long enough. Only those who have their heads firmly inserted into their *** has made any statement to the effect that this engine could not spin 7100 rpms with a heavier valve and CORRECT spring rate. What has been stated - by me, and others who actually have a basic understanding of valve train dynamics, is that without CONTROLLED testing, you will not know what the PEAK rpm capabilities will be for any given combination of valve train components. I for one want to be reassured that my engine can spin to NO LESS than 7600 rpm. I want to know beyond a shadow of a doubt that the valves will not start to float, or bounce at NO LESS than 7600 rpm. My reasoning is based on my personal experience with my car and missing shifts which resulted in over revving the limiter and seeing 7600 rpm on the HUD. Don’t tell me this can not happen, as I’ve seen it first hand, with my own eyes. Without testing this engine on a spin rig, or engine dyno, it is damn near impossible to know exactly what’s going on unless it’s bad enough to feel in the seat of the pants – and at that point, some damage is more than likely already occurred. Just because someone says that they spin their engine to 7600 rpm, “and nothing bad happened”, dose not validate that “something bad” is not happening.

Hopefully, the testing that Katech is preparing to do with aftermarket valves and springs will give those who are sitting on the fence the confidence they need that their choice in valve train components was / is the right choice. And I do mean that sincerely. With this information, end users will then know exactly what the hell is going on, and if they should move the rev limiter down, or up, or leave it where it is.

Originally Posted by 08VRZ06

DH

Thanks for sharing!! Like the track!! What the heck was that little car that went flying past you and then pulled away????

Mark

Originally Posted by Bill Dearborn

Howie,
Have you gotten any info on the condition of the valve guides in the heads you took off your replacement engine?

As for the track videos how was that BMW that passed you set up? I could see the wing on the back but it sure looked like he also had some suspension work done and was running some good R compounds the way he pulled away from you going through the long left approaching the Oval.

Bill

Originally Posted by Dirty Howie

Michael

I never got involved in those arguments as they were beyond my knowledge base. But they certainly did stick in my mind. And I was concerned enough to querry both my specialty shop (CMS) and WCCH. Richard said it would be impossible to tell a differnce.

I have done what I can to help bring useful data to the forum. I think the sound comparison let guys see that the beefed up heads sound great although technically a little louder.

The only way I had to indirectly prove that my motor is spinning up the same as before was to look at my final speed (which also corresponds to 4th gear redline)at a specific point of the track and compare it to many previous times at the same track.

Do you feel this is a valid methodology ?


DH

Originally Posted by '06 Quicksilver Z06

I know I wasn't asked, but I certainly do and want to put that out there now, while we wait for Michael_D's response to your question.

In addition, the comments by Charlie earlier, speak volumes about the success that he has seen himself and his experiences with these setups.

I'll take your methodolog, Charlie's methodology, and my own experiences over the "calculator" at this point.

It comes down to practical results. And that's what we have here. As opposed to theories and numbers spit out by "the calculator".

People don't care about "the calculator." They want to protect themselves from a windowed block.

The only ones who'll need "the calculator" are those trying to add up the total out of pocket costs of a dropped stock exhaust valve.

Originally Posted by Dirty Howie

Bill

Still waiting on the guide measurments from WCCH.

I run in the RED GROUP (open passing anywhere, fastest cars). Some of thes M3 have full aero, suspension, slicks and HP mods. Not sure which video you are noting. But I did track down the red M3 that finally threw in the towl and gave me the point by. I am on street tires !!


DH

Originally Posted by Dirty Howie

Sorry, forgot to ask you too

My motor was able to to beat back the HEAVY WIND and still get me to 156mph at 7K rpm just like it used to. So I am satisfied.

My only concern is that it revs too quick now causing me to hit the rev limiter


DH