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 Post subject: Answers to When is an engine Over Cam'd.
Posted: Sat Nov 12, 2005 4:07 am 
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This is a topic I started on another site and I post here for review and discussion. It is long, but has evolved over a short time. It is also a very frequently visited thread on the origional site I posted it on. Some is geard towards Bombers and Limiteds, and some for Sprinters. It is all good.

If you have a push rod V8, then here is where you will find what I consider to be very valuable info.

Cheers,

Shaun Tiede


Last edited by Shaun Tiede on Sat Nov 12, 2005 3:07 pm, edited 2 times in total.

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Posted: Sat Nov 12, 2005 4:08 am 
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Someone from this Forum asked me this excellent question in a private Email.

Here is my answer: Over Camming results when a cam is selected without prior knowledge about the cylinder head valve lift flow curve. The flow curve is measured on a flow bench.

In common language, it means you failed to do your homework. Therefore, your engine combination is not a winner.
In technical speak it happens when the valve lift exceeds the port capability to flow air.

Opening a valve in .100 lift increments while flow testing a head on a flow bench will show that on some heads (most of which are very commonly used at local tracks) airflow in the intake port begins backing up after a certain lift. The head flows less air at .550 lift than at .500. Therefore, installing a cam with more than .500 lift would be overcamming the engine.

Remember that the cylinder head is linked to the engine via the cam. The engine does not know that the head exists without a cam. You can have the greatest flowing and flow bench engineered pair of heads that anyone could conceive, but without the right camshaft to tie the knot, they are worthless. I have seen old school and out dated cylinder heads with no real technological value to them, but used with the right cam, circles around other heads that outflow them miserably at all lifts. The cam design was the deal breaker.

I have seen these old school heads in service on the Dyno and on the track. I have also witnessed them be replaced on the very same engines by the new and advanced designs of today. To everyone's disbelief, the new heads have been performance flops more often then one would believe. Many times, engine performance was less with these new and technologically advanced works of art then with the ancient cast iron mules they were designed to replace. However, after changing the cam, the engine delivered power numbers with the new heads that were inconceivable with the old stuff.

You can buy the best flowing pair of heads in the world, but if the cam is wrong, the heads will be wasted.

I feel it is very important for anyone seeking technical information to use much consideration regarding the sources from which they attain their information.

Case in point: I have had a very well respected head manufacturer (the best in conventional aftermarket bolt on heads in my book), call me many a time to sell a cam to one of their un-happy customers because the customer insists that their car is not any faster with the new heads though the new heads out flow their last pair by 20% at any given lift. In their ignorance, I can understand why they are Pissed. When I sell them what I consider to be the right cam for their situation, I get a call from the Head people telling me the customer is ecstatic because he just shaved a full second or more off of his 1/4 mile time slip.
I have seen it with my own eyes on more than one occasion, a great flowing pair of heads and the wrong performance cam running 14 second 1/4 mile times deliver a low 12 second 1/4 mile time slip with absolutely nothing done to the car or engine except a cam change! That is a cheaper gain than most N2O systems cost, and I think it is totally cool.

I believe that using a flow bench to evaluate a cylinder head is a vital step in proper cam selection. I also believe far too many never consider it. I feel the fewer amounts of tricks that the Rules state I can do to an engine, the more critical an issue that knowing what my head is doing becomes.


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Posted: Sat Nov 12, 2005 4:08 am 
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Weak Pushrods and Pushrod flex can also contribute to more cam than needed. There is considerable Horsepower and huge reliability to be gained by using a stiff Pushrod. The more spring pressure, the more the Pushrod is going to be Taxed.

I won't even begin to discuss the things I have learned from building and Dyno testing Pro Stock Engines, but I will tell you that the valve spring life and the rest of the valve train was drasticly improved when we installed Pushrods having a significant increase in wall thickness. It cut down on valve bounce 70%. That valve bounce will make the engine act like it has more cam.

I am not saying to go out and buy a set of high Dollar Smith Brothers Pushrods with a .165 wall thickness, but I am saying there is power and reliability to be gained even in the stock classes where whimp valve springs are the norm. Don't overlook the Pushrod. Even a readily available ChromeMoly piece with an .083 wall thickness is a great investment.

Then it's time to do what we do best.... GET IT ON!


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Posted: Sat Nov 12, 2005 4:09 am 
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Now I want to sell everyone on the ideas regarding valve diameters.
What I am about to say will hopefully discourage cheating.

Looking at flow data of an "old school" stock head on a flow bench, one can quickly conclude that unless the valve job is done with a radius cutter, and unless the short turn radius is corrected to the new valve size(port floor transition into the valve bowl), it is almost always a loss in low-mid lift air flow CFM through the port when a 2.020 intake and 1.600 exhaust valve is installed in a typical chevy head origionaly equiped with 1.940's and 1.500's! It also hurts the air velocity.

Remember the golden rule for Naturaly Aspirated Engines: Air Velocity in the intake port is King! Air Velocity=packing the cylinder with air. The result is that it makes more torque. Who would not want their engine to pull harder? The more port velocity, the more power because the air/fuel mixture is governd by the law of inertia just like your race car.

Big/early and lazy opening cams with their long and late closings will also MURDER velocity. Just look at the vacuum guage readings!!!

Insisting on a bigger valve diameter in the heads will negatively impact cylinder filling air velocity. The slower the RPM, the more negative influence a bigger valve will have. I don't see any "real" gains on small cubic inch engines with stock heads at RPM's less than 5500. By Today standards, 350 inch engines are small even for small blocks.

I am amazed at how many people assume that installing bigger valves and performing other tricks to the heads will do anything beneficial for an engine in such a case where the air flow restriction is not in the heads to begin with. Yes the heads are restrictive, however 2BBL carbs and/or the stock exhaust manfolds are a far greater restriction.

90% of the air flow gains to be had in these heads is in the valve job! (That is assuming that you are not welding up the port floors like we do in NHRA Super Stock.) I mean 90% of the gains are had in the valve job when you are also not trying to re-invent the head. The last 1/2 inch of port starting from the valve seat (the bowls/pockets) is the most critical place in the entire port with respect to effects on airflow. It has to have a venturi. Ever see a valve pocket where some "seeing eye" and brilliant head porter ground the venturi out if it and ground all the way out to the seat? This ain't right. The best thing to do is go in there with a 75-78 degree Bowl Hog cutter. It gets them nice and straight, and it is a 360 degree machined cut.

I will also mention that big, huge, and wide 45 degree seat angles KILL flow! You use a 45 degree angle, just don't make it a thick 45 degree angle. The actual 45 degree portion of the seat angles should be.040 wide on the intakes and .060 wide on the exhausts. I have seen 10% flow increases on the flow bench after using my C.N.C seat and guide machine as compared to a hand job done with a stone.

If rocker arm geometry is right, you have the valve job done on a seat and guide machine with a good operator who can line everything up straight, and then assemble with Viton seals, all that you will need after a full season of races on the heads, is to simply get some FINE valve lapping compound and lap the valves into the seats again and replace the seals with Viton seals. You WON'T need to perform a valve job again because everything will still be straight. Spend your money somewhere else.

Now back to the heads and cam thing. If you had a set of hedders, a 600-750 CFM 4BBL Carb, and an intense Solid Lifter camshaft with a 106 degree Lobe Seperation Angle, then the engine would be able to suck enough air through the heads to hit a wall. That wall is not going to be anything less than both 430 HorsePower and 6000+RPM in 350 inch engines.

My point: even if you have a pair of bigger than stock valves in your heads, and you have flown under the radar without detection by the tech department, I promise you the only way you will go slower around your super short 1/4 mile track with smaller stock diameter valves is because of tire spin from the increased torque to the rear wheels. I also very seriously doubt that anyone in Bombers or Limited Modifieds are able to turn anywhere near 6000RPM unless they are spinning the tires. I have seen many Limiteds turn 6500. However after installing a good tire couldn't turn 5000 the same night!

I can also bet the engines are going to blow up when the tires are hooked to the track rather than spinning because when the tires bite hard, that is when the engine is loaded in "GRUNT" mode and making power. For instance, the less load I put on an engine when it is on the Dyno, or stated another way, the faster I tell the Dyno to let the engine accelerate in RPM's per second, the less power it makes. That tells me that spinning the tires unloads the engine and sends it on a Sunday Drive.

I showed this very example to a driver in Killeen. He couldn't get it to the ground. We put on some new and legal Hoosier's just like we took off, and he blew it up that night. Funny thing was I told him he would blow it up that night because the tires would load the engine. Was too bad because he was starting the final lap of the King of the Hill race and he was nearly a full lap ahead of the rest. Would have paid him $2500.


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Posted: Sat Nov 12, 2005 4:09 am 
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Shuan,

The guys engine did not blow up because it was over cam'd or the tires were incorrect.

Engines blow up when they come apart from stress or are not built correctly.

The cam selection process is for the torque curve across the rpm range. Too much cam would mean loss os torque in the lower rpm range. However this loss can be corrected by selecting a lower gear ration on the drive train.

It is all a combination of the right parts that will get you what you want on the track.

The Fan


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Posted: Sat Nov 12, 2005 4:10 am 
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I do agree with you about the causes of engine failures. I said what I said previously because most of the engines running around there are sad build's by my standards. When you load them down and make them grunt, you find out real quick. The ultimate torture test for an engine is OffShore Marine Endurance. I do the Mercruider Marine reigning world record holding offshore Roller Cam. I also did their factory 454Magnum cam which ran 550 Hours full load and full throttle on their dock dyno.

Yes you can give it more gear. However, there comes a point in the Revs that the engine simply runs out of air. Once it hits that wall, gear is just going to make that happen before the car gets to the end of the track.

I do admit when my customer in Kileen installed the new cam, I saw the engine when he had it apart for the cam change since he pulled off the heads when he did it. Once I saw what I saw, I told him he was going to blow it up because the cam increased the cranking compression nearly 50 psi. He is actually a friend who lives real close, so I saw it all.

I am with you on the gear thing. I think the cars should run more gear and turn more RPM. However, most couldn't afford to race anymore due to the significantly increased engine Maintenance. suppose that is why most of them don't run 3 or 4 series gears.

If I was out there running, I don't care if I had a Bomber or a Limited, I'd gear that thing to twist 7000+ and stick a Rhodes Lifter in it. And I would build and cam accordingly. You can spread the LSA's on the cam to reduce the CFM demand on the Carb and therefore raise the RPM at which it hits the wall. I build 350 inch NASCAR Southwest and West Coast Tour Engines with Raised Runner Heads, 9:1, Solid Roller Cams with 700 lift at the valve, and 390CFM carbs with hedders and they have no problems running 8300RPM. That is with considerably less carb than a Holley 4412.

If everyone out here in Bombers or Limited's would run a small cam, they could fly with 110 Lobe Seperation Angles as the 110's have a really wide power band compared to 106's. Just don't run a big duration cam on a 110 in a low compression engine without any gear because it won't have any mid-range acceleration. Idle-6000+RPM powerbands: Small Duration cam, wide LSA!


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Posted: Sat Nov 12, 2005 4:10 am 
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Posted by another:

Money is the main factor in racing.

Ive know several guys who got into racing then got right out after finding that the track can take a big toll on the wallet even in the spending cap limited classes.


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Posted: Sat Nov 12, 2005 4:10 am 
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think that is because most people can't drive. And half of the ones who can, deliberatly aim their cars at others or block them to keep them from winning. But, that is a totally different issue than an over cam'd engine, and an issue which astute and judicious officials should deal with.


One thing that I see on low budget engines almost every time is the timing pointer is not true. Never assume anything, and especially regarding engines.
I replaced a cam in a Modified just this last week. When I found absolute TDC using a dial indicator with the heads off, it was off. WAY off. To get it right, I must have bent the pointer nearly 1/2 inch! Getting this one right is going to help anything run better. I have seen the little cheap Chrome bolt on ones be right on the money(surprisingly), and I have also seen them off as much as 15 degrees right out of the box on the same engine.

I would bet there are a few who would be surprised at what they'd discover if they started checking. Correcting spark timing which is 10 degrees retarded could sure make a big difference in water temps.


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Posted: Sat Nov 12, 2005 4:11 am 
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Also worth mentioning is knowing where the cam's Intake Centerline is installed in the engine. This is what it means to degree in a cam.

Here is a great example to illistrate the importance of the Intake Centerline and how it effects cranking compression.

First, the Intake Centerline is the spot which max lift occurs in relation to the crankshaft and is given in degrees after Top Dead Center. If you have a 108 Lobe seperation Angle, and you advance it 6 degrees, then that means the Intake Centerline is at 102 crank degrees after Top Dead Center. If you check the exhaust cam, it would be at 114 when the intake is at 102.

Now to the example. I sold a cam to a client who installed it himself. He called me the next day telling me his friends retarded it that evening. I think they were all standing around Drinking. He said the engine didn't sound at all the way it did when he installed the Intake Centerline where I told him to. I ended up going over to it to see for myself just what had been done. Since it had a Jessel Belt Drive on it, I could see immediately where it was in the engine. I discovered it had been moved from 100 to 110! That is retarding it 10 degrees from where he initially put it, and 4 degrees retarded from a straight up 106. I told him there was no wonder why the engine sounded dead. It was! The cylinder pressure had all been killed.

I decided to prove a point to him by performing a Cranking Compression test with the cam retarded in the current position compliments of his Genius Buddies. For the record, we never even removed the valve covers the entire time I was there. The engine was Ice-Cold. It only made 170PSI even with having a 13.8 to 1 compression ratio! That is approximately a cranking compression reading of a stock engine having a stock cam and only 9.5 to 1 compression or less.

I moved the cam back to the 100 Intake Centerline(advanced it 10 degrees from where his Genius friends had it), and the Cranking Compression was now reporting 230PSI. That just TRIPPED the Guy out!

A 60PSI increase in Cranking Compression is drastic. You'd feel a gain with 20.

With an externally adjustable belt drive, you can move the cam in less than 1 minute even with the engine in running form!

Needless to say, we fired it up, re-calibrated the ignition timing, and everyone listening in the shop said the engine sounded COMPLETELY different, and that it sounded like it did before they messed with it. They all said the crackle out of the exhaust is back. Of course it was, what would you expect with another 60PSI in cranking compression!

It pay's to know where the Intake Centerline is.


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Posted: Sat Nov 12, 2005 4:11 am 
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390 CFM is the Rule for all of them. They are enhanced with circut work, but they are not opened up beyone specs. NASCAR Tech is the tightest and toughest Tech you will find anywhere. Once the cars qualify, they are confiscated by the Tech Police and locked up in a high security building. No one can touch or go near the cars after qualifying. They can't even put Gas in them.


The purpose is to restrict the power by restricting the airflow into the engine. The initial result seemed to produce the desired significant reduction in power with the added benefits of leveling the playing field of performance. BUT VDL WENT TO WORK AND CHANGED ALL THAT!

Whenever a carburetor is sized improperly to the engine, there are a variety of problems that arise. The air/fuel circuitry was designed for a low air speed/horsepower application. When this design is applied to a high air speed situation it produces a rich, poorly emulsified fuel mixture. Many carb builders have performed extensive dyno and track testing to recalibrate the air/fuel circuitry, accelerator pump circuitry, and idle circuit to produce optimum torque, horsepower and drivability.

Airflow is of the essence with a restricted carburetor. VDL takes every part of the carburetor and maximizes the potential airflow while still operating within the tech parameters. This is where it gets very tricky. For whatever reasons the tech tools have evolved to allow a significant amount of modification beyond the stock sizing. From booster dimensions, booster location, and throttle shaft width to venturi height, this carburetor must be custom fit to the tech tools. The performance gains from these modifications are in the 25 horsepower range! Obviously not something you can afford to leave on the table.

The other aspect to the dimensional aspect of this carburetor is that each series' tech seems to vary just a bit, requiring VDL and other carb builders to build a specific carburetor to each series application. Now what do you think of your "out of the box" carburetor?

After the parts are machined to the minimum/maximum sizing, they are vibratory polished and re-coated. Assembly is done to tolerances unobtainable in high volume production. Boosters are installed to within .001" on height, twist and pitch. The base plate is matched to the main body. All gaskets are properly matched to the main body to prevent overhang. And finally, the throttle plates are adjusted for optimum position on the flow bench. VDL and other carb builders produces the absolute best custom-built 390 CFM carburetor available. Built to your specifications and engine application -- not just another "out of the box" carburetor.

Limited Racers with 500CFM Holley 4412's would be spending wisely if they had their carbs worked by some of the pro's in California, Alabama, and other places. They are not cheap, but well worth the money.

I would opt for a professionally built Quadrajet before I would ever consider a Holley 500CFM 4412 since the rules allow Quadrajets on Limited's. Quadrajets flow over 780CFM! They are extreemly well engineer'd pieces. You just need to understand them and have one built by someone who KNOWS them. That is the key. Consequently from most people not understanding them, they get a bad rap. I won an NHRA Super Stock National Championship Title running a 700HP Big Block with stock cylinder head castings, AND a QuadraJet on it.



Now that this topic has been Hi-jacked into carbs, lets get back to cams.


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Posted: Sat Nov 12, 2005 4:12 am 
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To further reduce/offset the Stranglehold that a small CFM 2BBL carb places on an engine, and especially one with low compression (2BBL equipped engines are low compression with anything less than 13:1) one should look into trying a reverse pattern cam such as we put in Turbo charged engines.

Remember: with an open hedder and a restricted induction system, the exhaust side of things starting with the cam, is NOT where the engine needs any help.

The smaller exhaust cam will really wake up the low speed torque and vacuum. This could be a real help to cars with really tall gears.

The main reason we need tons of compression here is because we are spinning engines high enough in RPM to put the CFM demands way up there, and far beyond the 390-500CFM carbs ability to feed it. When you stranglehold the thing, you have to squeeze the crap out of what little air it gets because there is such a reduction in total volume to start with. Having a compression rule and a Hydraulic cam rule in a few of the classes at Cow-Town forces one to need to strongly evaluate the issues before simply throwing a cam at it. Yes, cams are the heart of an engine combination, but the instant there is a choke chain wrapped around it, that becomes the achilles heel which everything else in the entire engine combination MUST focus upon. Most of what you know about cams and engines equipped with 4BBL carbs and open hedders
does not apply and is irrelevant!
This is especially true when you use "REAL" cams with super fast ramps and tons of high lift area. They really try to move the air in and out. They can make the cylinder head lie to the engine and trick it into thinking it has much more head flow capacity then it actually does.

This is what is done in NHRA Super Stock where factory stock head castings are mandatory. We have to crank the valve off of the seat and reach the lift at which max port flow occurs. Then we try to keep it there as long as possible without creating a cam with an extreemly high negative nose deceleration which tends to toss the lifter off from the nose of the cam lobe, thus hurting power and killing valve train dynamic stability. This is also why I hate POINTED NOSE(Hatchet Cams) and DWELL NOSE cams.

Ever seen the black exhaust gas deposits in the intake port or under the lid of the air filter? This is the classic sign of intake port reversion. It is a sign of an extreemly early opening and late closing intake valve, and/or the evidence of intake valve bounce during the compression stroke. And there are only 2 reasons for it. One is a crappy cam design such as a Symmetrical design which closes and seats the valve with the same aggressiveness as it opens it (because it is the same shape on the closing side as it is on the opening side) or 2: there are some really weak valve springs.

Increasing spring pressure is necessary to a point simply to deal with the weight and inertia of the actual valve train components. However, some cam designs and any symmetrical one by nature of the shape of the lobe, needs more spring pressure to deal with the lobe dynamics. I feel that running more spring pressure to cut down on a valve bounce problem is a band-aid approach. Installing a cam with a short and fast opening ramp and a long gentle closing ramp will open big doors.


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Posted: Sat Nov 12, 2005 4:12 am 
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have spoke with many racers all over the world. I am surprised at the extreme ranges of Cam Lobe Seperation Angles racers are using. I hear some with 105-106's, and I hear several others with 112-114's.

The bigger duration a cam has, the more acceleration a wide lobe seperation angle cam is going to take out of the engine. A low compression engine especially. It is going to give the sensation that the engine is on the verge of exploding into the powerband. The driver will think "just a couple hundred more RPM's and she'll come alive." But it never does.

The opposite is true for tight LSA's like 106's. The problem with them is one: they are explosive. And two: they have peaky and narrow power-bands. When they are on, they're on. But, when they peak, they're done. They are also a problem wich compounds the traction issues with the tire.

Some of you who shop for cams are worried about vacuum. The tech on the other side of the phone tells you a wider LSA will help that. Yes to an extent that is true. However, considering the relatively low rpm's the vacuum rule engines are running, if you have to run 112-114 LSA cams to meet vacuum rules, you have too much cam duration for the usable rpm range! A wider LSA is a Band-Aid. Try smaller cams with a 108LSA. If you run a single pattern cam, it will really help bottom end and vacuum. With small durations like 215@.050, you can get away with a 110. If you run a hydraulic cam and you can't see the high side of 6200RPM's unless the tires are spinning, you are wasting your time putting a 112-114 LSA Cam bigger than 210-215@.050 into your 350 cubic inch engine.

If you want to run a 114 LSA cam in a bomber or limited, I'd bet Money you will run faster with the stock cam than one with 280 Advertised and 230+@.050 with a 114LSA!

You need to make the car zing off the turns. Unless you are running a ton of gear (which would put the engine RPM at the end of the track way over the induction systems ability to feed it air anyway), a big hydraulic cam with 235@.050 numbers will have to be on a wide LSA to even dream of meeting the vacuum rules. Unless you put an original Rhoads lifter in it. And unless a cam like that does run with a Rhoads lifter, it will be a PIG just about anywhere in the RPM range you will use it.

There are cases in bombers or limited's where 114 LSA cams combined bigger durations can work. But it is not on a 1/4 mile track in a car having 2:73 or 3:08 gears. Nor is it in a low compression engine and a 3000-6000RPM power range.


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Posted: Sat Nov 12, 2005 4:13 am 
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am getting feedback from some racers here who are saying that cams and cam specs are Greek to them. Cams are a prime example of "what you don't know or understand will hurt you." I think it is risky leaving your odds and chances to luck.

If something is not easily understood because of the depth of the subject matter then keep reading, or read it again. Get off of Caffiene first. LOL!

If I am getting too deep for others to understand my point/points, then tell me. I really make an effort to write in a way which is easily understood by someone even with very basic knowledge of the subject.

The ultimate display of Faith is to simply put the information to the test. Then there will be Sure Knowledge

The cam is the great air flow controller in the engine. Since air flow is power, then it should make perfect sense to understand everything about the cam first. Then use that info and tie it into the cylinder head because the cam is the cylinder head's link to the engine, and the two go hand in hand.


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Posted: Sat Nov 12, 2005 4:17 am 
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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!


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Posted: Sat Nov 12, 2005 4:18 am 
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Joined: Thu Nov 10, 2005 11:06 pm
Posts: 23
Location: Austin, Tx
For those who wish to call and ask questions or discuss anything rather than typing our hands off, just give me a call.

512-238-6065.
817-917-6497 Cell, In the eves/weekends.

P.S. Please if you call me, don't call after 8 PM or on Sundays,(it's a Wife thing), and I do return calls if you leave message


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