A bit off the subject perhaps, but a plea to one track to give the Vortec head a chance.
Before you read this remember that there is strength in numbers!
Since an engine being over cammed relates to the cylinder head flow curve with respect to valve lift, it would sure make SB Chevy engines much more reliable if the SB Chevies were allowed to use the readly available Vortec head. Casting numbers 906 and 062.
They reduce spark advance requirements which also significantly reduces Brake Specific Fuel Consumption and increases Torque at all RPM's. They have a fast burn style chamber and a revised spark plug location as compared to the old stuff.
They are much cheaper to come by than the old stuff too. They are unleaded fuel compatible, have really hard/reliable seats, and have the same chamber and port volume as the old closed chamber heads but will out flow them 20%. And they won't quit flowing at .500 lift like the old stuff will. Out of the box with stock valve diameters, they will murder a big valve Dart 200cc head in the low-mid lift flow, and they will just about flow nearly the same at 600 lift. The old open and closed chamber heads of the late 60's and 70's era's won't even come close though they all have nearly identical intake and exhaust port volumes. This proves my point when I say that the shape of the port is even more important than its size.
The old stuff is so hard to find in good rebuildable condition anymore. Especially ones that some brilliant "seeing eye" head porter has not already widdled on, ruined, and are therefore illegal. Other than ignorance, I just can't understand why racers would use them. it is 2005. You wouldn't buy a Computer dated even ten years ago let alone one dated back to the time these heads were designed. The only reason these cars are fast is everyone is doing the same thing. As for them being fast, I ask the question: Compared to what? I tell people all of the time when they talk about their old tech beast having all of this power that they don't know what real power is.
Countless times I have put engines on the dyno to evaluate them when a client wants me to make them more power. I tell them I won't touch it before it is dyno'd because he say's it makes 450, and I say there would have to be a miracle for it to crack 350, which it half the time won't even do that. They are shocked. Like I said they don't know what real power is. They think they have 450. They wouldn't know 450 if it stared them in the face. I can make over 400HP out of it with Vortec heads and nothing more than an RV cam. And it idles as calmly and quietly as your Fathers Oldsmobile! When you are used to building N/A engines which make well in excess of 2Hp per cubic inch, the stuff you need to run at Cowtown is a Sunday drive.
My first secret for you all to go fast is turn RPM's. RPM's is like adding cubic inches!
Before long, Vortecs will be old and all that is available for the older small blocks. It is very difficult to impossible to find a rebuildable set for sale by anyone who doesn't want way more Money than they are worth becuse they know that these Dinosoars are just about extinct. All of this makes them more expensive to build than a Vortec Casting.
If the secondary purpose for the rules in the majority of classes at Cowtown are intended to keep engine costs affordable and reliable, then it makes economic sense to allow these newer head designs a chance on the track.
They will reduce costs by reducing stresses on the lower ends of the engines via the reduced spark advance requirements. Just watch what slow burn speeds and the resulting needs for additional spark advance requirements do to an engine's torque production on the Dyno. Especially at low RPM. The mechanical efficiency (the power an engine requires of itself to rotate) TANKS! The Mean Effective Pressures are simply fighting the upward stroke of the crankshaft. The earlier the plug has to fire, the worse it gets. This really loads the rods and bearings. It also puts heat into pistons and chambers. Perfect for improving the environment for Detonation.
So what, there would need to be a different intake. Big Deal!
One can also get a Fel Pro 1255 intake Gasket to convert the Vortec intake flange to an old style intake.
I really don't see the difference in just allowing an Edelbrock Performer intake (not a performer RPM) because the performer is cheap, a very old/out dated design (just like the old factory heads and intakes), and it is virtually a clone of the old stock intake anyway. It is not like it has any real power advantage above the old school stuff everyone is currently using.
The raised valve cover rails on the Vortecs would also eliminate valve cover leaks thus adding to the saftey of the track surface by reducing the chances of oil getting onto it. For tech or service reasons, I can get a cordless drill with a 1/4 inch socket attachment, and have the valve covers off in less than 30 seconds! I am a firm believer in working smarter rather than harder. being allowed to run Vortec heads will definately be a big step in the working smarter direction.
If enough racers ask with one voice, they just might be allowed to run them. If they don't stand up and ask, then I am sure they won't.
Not to get off on another track, but that is the main problem with this great country. There are too many bad people getting away with bad things because, and even though the good people still far out number the bad people, the bad people and/or people with evil ideas are the only ones who are in the majority of standing up for their cause. They get rules changed and laws passed because the good people with high standards and values are either too busy to be heard or won't open their mouth's. Therefore they give away their power. Nothing changes because of their silence. That is why I call them the "Silent Majority."
The close of the season is drawing nigh. Rules are soon to be evaluated for the next season I am sure.
don't be the silent majority, make a combined stand for the Vortec Heads!