Failure to hump AFR leg

[Sky65]

OK, since we're talking about marketing here's one I'll throw out to the peanut gallery.

The entire AFR story is based on small port big flow...all the rest of the bullshit stems from there.

Why is it, with the BILLIONS spent on R&D in professional racing, offshore boat racing, 9,8,7 second cars....all that money spent on R&D and to beat the next guy by .01 second....why is it that no other manufacturer takes that path?

Does Brodix, Dart, All Pro, Edlebrock, TFS, Canfiled, not have the money to do it? Do they not have the smarts? If it were that good wouldn't EVERYONE be doing it? Makes me skeptical to say the least. And this thing about lightened valves, same question.

To me, I think it's a bling factor...no basis in science or reality, just something cool to talk about and impress your schoolyard chums.

I gonna step into the water here, please don't drown me.

My understanding is the small ports improve low/mid range torque. High flow is for top end hp. In a race engine run full bore all the time no one cares about the bottom end. Top end and hp is it. On a street car you need the torque. On a street car small runners with high flow would be the ideal? Have I just drank the AFR cool-aid or is there some fact to that premise?

That's the cut and paste. Here's a little more.

Port size has an effect on power band and where the torque lies, yes. If this were the case, we'd all be seeking L98s, not LT1s right? After all the L98 has more torque.

To say "on a street car you need torque" is a gross generalization and assumes that everyone wants the same thing out of a motor. How much torque do you need? I can't ge If you prefer torque and you think that's better, that's up to you, there's plenty of ways to get it.

If you believe that AFR is the only company that can offer performance, then yes, you drank the Koolaid.

I don't believe AFR is the only company that can offer performance. Yes, I have been considering AFR heads. I have a 350 in my 65. It is a driver, a street car not a race car. I like cars that set you back in the seat when you stomp the gas. I have a Richmond non-overdrive 5 speed with a 3.08 rear. What head, cam, intake and carb size would you recommend to set me back in the seat without breaking the bank?
Thanks

 

[Jsup]

I don't believe AFR is the only company that can offer performance. Yes, I have been considering AFR heads. I have a 350 in my 65. It is a driver, a street car not a race car. I like cars that set you back in the seat when you stomp the gas. I have a Richmond non-overdrive 5 speed with a 3.08 rear. What head, cam, intake and carb size would you recommend to set me back in the seat without breaking the bank?
Thanks

Depends on your criteria. If you decide that AFR is the right head for you, that's terrific, go buy them. I hope you enjoy them and they do everything they can for you and are everything you wanted. All I have ever said is, there's more than one brand on the market, and perhaps once your criteria is identified there may be a better solution. I sincerely appreciate your willingness to at least consider that there are other products. I betcha when you hopped on forums no one ever had the discussion with you that I'm about to have below. They simply told you that if you want to make power go buy AFR and that's all the information you were ever given. Perhaps they even "knew a guy" or something.

Tell ya what, Dart has a fantastic message board. Go there, get their story then come back and ask us if they are feeding you buillshit. Once you are armed with that information, you can make the informed decision. $1500-2000 is a big purchase, check them all out, listen to all their bullshit, ask questions about the line they are feeding you, then decide. Has anyone on another forum ever typed the word Brodix? Dart? Patriot? All Pro? Canfield? anyone? No, you probably asked a question and got one answer.

I lifted this from another forum I post on, Hotrodder's forum:

I did some research on heads and was narrowing in on a set of Dart, Iron Eagle cast iron heads due to durability concerns with aluminum (old school I guess). I called Dart to discuss and the tech said Dart really didn't make a head for the 396 application due to their head being designed for 4.3 minimum bore and he had concerns for valve to block clearance. This tech further recommended I consider using an Edelbrock head since they had more offerings for the 396 application..Huh. If I go with Edelbrock, I may do the top-end package if I can't determine my cam spec's. I'd rather use what I have (cam, TC& gear) and use the money elsewhere if possible.

How many manufacturer's tell you to go buy someone else's product?

When I hear things like "without breaking the bank" I think Brodix IKs. You can find them for under $1000 and they are a fantastic head. The 200s support over 600 HP easy. The 180s will probably work for a 350.

Look, picking parts is a process. If it were me, and it was, first pick your criteria. How are you going to drive it? What operating range?

Then, IMO, PICK THE CAM FIRST!! Get the cam card. Duration will determine your operating range, ramp will start to guide you toward heads. Ramp will be critical.

A modern camshaft like one produced by CompCams will utilize a very aggressive lobe design. The idea here is simple, cylinder heads used in racing classes often have to sacrifice low lift airflow (.100-.300) in order to get the very high flow at high lift numbers. They have found that through camshaft design that they can generate more hp through a pretty simple concept. Now many will talk until they’re blue in the face that a good head has superior low and mid lift numbers and that is not entirely correct. SURPRISE!!!

If for example, you are going to use a 1.7 rocker to achieve .675 lift (with today’s valve springs and valve train parts is not a big deal for a dual purpose engine) and you are utilizing a new CompCams solid roller you are wasting your time focusing on lift numbers and here’s why. The aggressive lobe was designed to get the valve quickly (very, very quickly actually) into the .400 lift and higher range. You also sped the process up a bit by using a higher ratio rocker. The end result here is simple, you have a package that is designed to get the valve open quick, and stay open for as long as possible (when the valve spends most of it’s measurable time at high lift, it’s best to get your flow there). You also (since you read the above) have a well tuned exhaust tract that is aiding in the initial cylinder filling… In other words, IT’S ABOUT THE COMBINATION!!!

To boil it down I am a firm believer in the decision making process which is determined by the cam, then work toward the rockers, then the intake THEN you can pick a head. Without knowing all this other stuff, how do you know what head you need? The cam will set the tone for the rest of the motor. Pick your operational environment, pick the cam, look at all the specs, then we can discuss.

 

[brngrhd]

i still think that you have to chose the heads you want after getting as much info as possible THEN pick the cam..... there can be things that will be different based off the heads you chose...... on another forum where lost of people are AFR leg humpers they say that you don't need as much split on the cam since the exhaust flows so well.... now mind you i don't think it will make that big of a difference when compairing it to say a set of pro-1 heads as long as your compairing like heads like 310 pro-1 to the 305 AFR and the bigger cnc heads to each other..... ok i'm done rambling...

 

[Jsup]

i still think that you have to chose the heads you want after getting as much info as possible THEN pick the cam..... there can be things that will be different based off the heads you chose...... on another forum where lost of people are AFR leg humpers they say that you don't need as much split on the cam since the exhaust flows so well.... now mind you i don't think it will make that big of a difference when compairing it to say a set of pro-1 heads as long as your compairing like heads like 310 pro-1 to the 305 AFR and the bigger cnc heads to each other..... ok i'm done rambling...

IN my opinion, for the reasons I listed above, pick the cam, the intake, the rockers, THEN the heads. How can you pick a head when you have no idea what intake and cam are going on that, and the rockers are all part of that formula? It just makes no sense to me. The cam determines the operational environment which the purpose built engine is going to provide. Not the heads.

There again is another myth. 900HP RACE CARS are flowing less than 240CFM on the exhaust side. Exhaust flow numbers are basically meaningless in our applications.

This is one that every professional I talk outright laughs at; the idea that a cylinder head has to flow a ton on the exhaust side to make good power. When I ask this question I usually get a response like “a 900hp race engine has an exhaust port that flows 250cfm, so why would you feel that a street engine needs one to support 500-600hp?”. Does sound ridiculous on the face of it doesn’t it?

Think about this in terms of airflow demand just as we would the intake side. Again, the shape and tuning of the exhaust is what pulls the last bit of exhaust out and first bit of intake charge in, not the flow number. In other words, in the absence of real design work being done, go for brute force, or big numbers. This is not a design, this is a guess. Think of a siphon, if you’re simply letting water run out of a hose, vs, a siphon sucking it through, that’s what port design and wet flow (on the intake side) will do for you and that is why exhaust flow numbers are meaningless. That is why we put X pipes in our cars. Isn’t it? If you don’t subscribe to the above, I will expect we should all be pulling out our X pipes tomorrow..

Therefore, a few engine builders have expressed that they do not feel that restriction in the exhaust port is anything to really look at, the flow bench number, and it has no value. To them it’s all about tuning that tract to do the above. Many will cite how unimportant cylinder head flow numbers become when a supercharger is added to the intake side as some of the reasoning they feel that exhaust port flow numbers are not the hot ticket. So essentially, this exhaust flow thing you’re going to hear is utter nonsense perpetuated by the ignorant, ill informed and uneducated.

 

[Jsup]

i still think that you have to chose the heads you want after getting as much info as possible THEN pick the cam..... there can be things that will be different based off the heads you chose...... on another forum where lost of people are AFR leg humpers they say that you don't need as much split on the cam since the exhaust flows so well.... now mind you i don't think it will make that big of a difference when compairing it to say a set of pro-1 heads as long as your compairing like heads like 310 pro-1 to the 305 AFR and the bigger cnc heads to each other..... ok i'm done rambling...

Which never happens. You can have Dart CNC any one of those heads then the "flow numbers" don't really compare.

I'd even throw in the Brodix X-10s and X-11s. These are GREAT for big motors and there is no AFR product that can match it.

Here's a story. I cooked up a fake build on another forum. Custom designed by parts and applicaitons for the Brodix X-10s. I mean, there was NO OTHER CHOICE.

So in an experiment I had someone else post the config and ask which head.

I chimed in and gave at least 10 reasons why the X-10 was the perfect head. No one discussed my reasoning. No one asked why I thought what I thought. They just ignored it and went straight to AFR 227s. That right there is what I call a leghumper. That right there is bad internet advice.

 

[brngrhd]

i still think that you have to chose the heads you want after getting as much info as possible THEN pick the cam..... there can be things that will be different based off the heads you chose...... on another forum where lost of people are AFR leg humpers they say that you don't need as much split on the cam since the exhaust flows so well.... now mind you i don't think it will make that big of a difference when compairing it to say a set of pro-1 heads as long as your compairing like heads like 310 pro-1 to the 305 AFR and the bigger cnc heads to each other..... ok i'm done rambling...

IN my opinion, for the reasons I listed above, pick the cam, the intake, the rockers, THEN the heads. How can you pick a head when you have no idea what intake and cam are going on that, and the rockers are all part of that formula? It just makes no sense to me. The cam determines the operational environment which the purpose built engine is going to provide. Not the heads.

There again is another myth. 900HP RACE CARS are flowing less than 240CFM on the exhaust side. Exhaust flow numbers are basically meaningless in our applications.

This is one that every professional I talk outright laughs at; the idea that a cylinder head has to flow a ton on the exhaust side to make good power. When I ask this question I usually get a response like “a 900hp race engine has an exhaust port that flows 250cfm, so why would you feel that a street engine needs one to support 500-600hp?”. Does sound ridiculous on the face of it doesn’t it?

Think about this in terms of airflow demand just as we would the intake side. Again, the shape and tuning of the exhaust is what pulls the last bit of exhaust out and first bit of intake charge in, not the flow number. In other words, in the absence of real design work being done, go for brute force, or big numbers. This is not a design, this is a guess. Think of a siphon, if you’re simply letting water run out of a hose, vs, a siphon sucking it through, that’s what port design and wet flow (on the intake side) will do for you and that is why exhaust flow numbers are meaningless. That is why we put X pipes in our cars. Isn’t it? If you don’t subscribe to the above, I will expect we should all be pulling out our X pipes tomorrow..

Therefore, a few engine builders have expressed that they do not feel that restriction in the exhaust port is anything to really look at, the flow bench number, and it has no value. To them it’s all about tuning that tract to do the above. Many will cite how unimportant cylinder head flow numbers become when a supercharger is added to the intake side as some of the reasoning they feel that exhaust port flow numbers are not the hot ticket. So essentially, this exhaust flow thing you’re going to hear is utter nonsense perpetuated by the ignorant, ill informed and uneducated.

well i guess i agree there like you said before one really needs to site down and think about the whole build not any one part..... total package kind of thing....


yes a agree that flow numbers are not as important on the exhasut since the piston pushes it out rather then making atmosphere push it in.....

 

[Jsup]

well i guess i agree there like you said before one really needs to site down and think about the whole build not any one part..... total package kind of thing....


yes a agree that flow numbers are not as important on the exhasut since the piston pushes it out rather then making atmosphere push it in.....

Yes. The first question is "what do you want" and the answer isn't "the most power I can get". The question really is "how are you going to use this thing"......think about that, long and hard before picking part one. If you don't, you'll never get what you want. THEN pick a cam that reflects that. Now you have the duration, lift, now pick a rocker. So now you know where you sit. If you come up with .515 lift, you don't need a head that flows at .700. Now the intake, then you know your intake restrictions and purpose. Single plane? Dual plane? TPI? Miniram? What? You're intake will determine the characteristics of the engine. NOW you're ready to choose a head based on all the stuff you did above. The head is a SUPPORTING PLAYER to a large extent, not the main chracter.

This is yet another example of AFR marketing, not fact. AFR says "we have higher exhaust flow numbers". No one ever questions if that has any benefit, they just run out and tell people they need higher exhaust flow numbers. Based on what? AFR say so? That's a leghumper.

Like I said eariler, with billions spent in this business all the other manufacturer's could EASILY raise their exhaust numbers if it had any value, it doesn't. Ask yourself, are all the competitors that stupid? Are all their customers that stupid? Is AFR that brilliant that they figured out that exhaust flow is really important? no, they aren't to all the questions.

I just don't want that tidbit of marketing bullshit to be a determining factor in your decision. If, once we take each manufactuer's bullshit and weed out what matters, then a decision can be made in both budget and application.

 

[Jsup]

Bottom line is that this is all about one thing. VOLUMETRIC EFFICIENCY. Period

Air compresses, becomes more dense in engineering terms, at .6 mach or so. Fact of the matter air speed so rarely reaches .6 mach inside an engine for all intents and purposes, engineers ignore compression as a factor. There is not "turbo charging" effect claimed by the leghumpers. Not to say that port velocity isn't important, the point is there is not "effect" because you will never, or very very rarely, reach over 100% VE on a naturally aspirated motor.

Therefore, the goal is to get as much VE as you can, and accepting that once 100% VE is reached you can do no better. This can be determined by your cam duration, total lift, and ramp. Based on that you can determine valve size, 2.02 vs. 2.05 and such, and what flow you need to get to 100% VE. On a small cam you may NEVER reach 100% VE, so the head flow has less value.

NOW, there's two ways to get VE. Either through port VOLUME (big ports) or port velocity (small ports).

Think about this....if you pinch off a garden hose you are pushing water into the bucket more strongly, but not more quickly. If you take your thumb off the hose the bucket will fill at the same rate as if your finger is on it. So at the end of the day, it's the same VE. Smaller port vs. bigger port analogy. Now understanding that compression is not a factor in a motor (compressing air to be more dense) the bigger port may be better in that it can fill the "bucket" faster in some cases.

Here's the question.....do you know what the real flow number is for a 350 to get 100% VE on an intake stroke under ideal conditions? I don't. I'm sure someone out there does. Once you know that number, there is no need for heads that can flow any more than that. I'd love to know that number.

Now you get into the realm of port design. As we discussed, technology like Spintron and Wet Flow are how you can see this stuff. Without that it's a hand port and flow process. Hack and guess if you will. It is impossible to design a head on a dry flow bench. All a dry flow bench is good for, and flow numbers, is to tell you the changes you made to a head when porting, after the heads were designed using other technology.

 

[Jsup]

OK last thought. One of the most annoying lines ever....."these heads make great power".

Heads don't make power, engines make power.

Dart is the only manufacturer I know with a message board. Go there. Tell them what you're thinking and that you're seriously considering AFR. You know what the response is going to be, but better to hear it and judge it, rather than to ignore it exists. Ignorance is not a way to pick parts.

 

[guru]

Need to determine your criteria:
How fast you want to go in what racing venue
If not racing, displacement and RPM range

Determine your constraints first:

My headers have to fit - This could mean a stock location and an appropriate sized port (for example not a D shaped exhaust port)

Needs to fit under my hood - could lead to intake manifold height concerns, which could lead to intake port limitations

Cash on hand

Transmission

Rearend (not necessarily a constraint)

Your entire top end sort of dictates the other, and you have to pick a place to start.

 

[mrvette]

For years in various posts, I have always said, FIRST you have to know what you want the car to do.....before any engine decisions are made....

wide/narrow ratio tranny/type of tranny, rear ratio...car weight target +300 lbs on account of physics....:tomato:

so for my little street build, I wanted a torquey 400 hp 355 in engine....

little disappointed about the fuel economy....I would have hoped it got more like 26+ mpg like a '87 did, but not to bee....

:quote:

 

[clutchdust]

Was it Trick Flow or AFR that has the canted valves like BBC???


:bonkers:

i totaly wanted a set of those. really hard to find now. i asked a guy at SEMA a couple years ago why they stopped making them and he told me it's because their new conventional (non-canted valve) head was within 5% on the same engine combination and they just couldn't sell those canted valve heads for the cost of manufacture against the conventional heads.
still, i'd like to have them just for the cool factor.
no AFR leghumper here.:kissass:

 

[Twin_Turbo]

You can buy mine for 2000$ or i'll trade a set of AFRs straight up

 

[Jsup]

You can buy mine for 2000$ or i'll trade a set of AFRs straight up

Isn't TFS putting out a 21* head now that fits 23* applications?

 

[Jsup]

Well, looks like AFR wins another forum. I have become very unwelcome at another forum because I don't subscribe to AFR leghumping

I'm not banned from there, I just don't feel welcome. Leg humped right off the forum.

WTF is with people? Over a fkn chunk of aluminum. Sigh.

Shame too, I thought there were some really nice people over there. Just some of them can't get the dam bee out of their bonnet over AFR. Every single thread that mentions mods or heads has to be met with a claim of AFR superiority either in that thread, or started in another thread. Someone mentions Dart, Brodix, etc.....within an hour an "Here's why AFR is great" thread pops up.

Anyway, we need to get more traffic up here so I can stay entertained. Thanks for letting me vent.

 

[mrvette]

You can buy mine for 2000$ or i'll trade a set of AFRs straight up

Isn't TFS putting out a 21* head now that fits 23* applications?

Summfin elementary I don't unnersand....what are they talking about in all this 'degree' on a cyl head??? the valves are on the same plane, stems parallel, NO?? or is it something to do with the plane of the intake face mounting to the plane of the head gasket surface???

 

[Jsup]

You can buy mine for 2000$ or i'll trade a set of AFRs straight up

Isn't TFS putting out a 21* head now that fits 23* applications?

Summfin elementary I don't unnersand....what are they talking about in all this 'degree' on a cyl head??? the valves are on the same plane, stems parallel, NO?? or is it something to do with the plane of the intake face mounting to the plane of the head gasket surface???

The angle of the valve relative to the deck. Changes the air flow that it has a shorter path with no turns, there for less turbulence. 18 degree has been the popular number now, but new heads are down to 12 and 13.

 

[mrvette]

Which valve, intake or exhaust?? and that's off the head gasket surface?? that would be 90* in most cases, so you saying the stems are 12-22? degrees tipped toward the intake manifold...that makes sense....but what about the exhaust?? I understand one reason the 440 mopar engine had constant valve cover leaking was the manifold flange on exhaust was putting the headers too close and frying gaskets....but if the exhaust valves were done like the BBC or HEMI, it wasn't a problem....hense the olde original AFR/canted valve design....

so why doesn't Detroit go there???

guys talk of Vortec with taller intake runners so the older shit don't line up, WTF goes on there??? I would go Vortec in a flash IF I could get a cheep enough DPFI manifold for it, but just what does that buy over my present setup???

shit like that I never seen a succinct answer for, just snip and snaps of threads that never add up too clearly for me....

:surrender:

 

[Jsup]

Which valve, intake or exhaust?? and that's off the head gasket surface?? that would be 90* in most cases, so you saying the stems are 12-22? degrees tipped toward the intake manifold...that makes sense....but what about the exhaust?? I understand one reason the 440 mopar engine had constant valve cover leaking was the manifold flange on exhaust was putting the headers too close and frying gaskets....but if the exhaust valves were done like the BBC or HEMI, it wasn't a problem....hense the olde original AFR/canted valve design....

so why doesn't Detroit go there???

guys talk of Vortec with taller intake runners so the older shit don't line up, WTF goes on there??? I would go Vortec in a flash IF I could get a cheep enough DPFI manifold for it, but just what does that buy over my present setup???

shit like that I never seen a succinct answer for, just snip and snaps of threads that never add up too clearly for me....

:surrender:

Detroit has gone there. LSX

As far as Vortec goes, if you want a lot of guys who are real big on Vortec...go here:
http://www.hotrodders.com/forum/

They LOOOOVE Vortec there.

 

[mrvette]

Which valve, intake or exhaust?? and that's off the head gasket surface?? that would be 90* in most cases, so you saying the stems are 12-22? degrees tipped toward the intake manifold...that makes sense....but what about the exhaust?? I understand one reason the 440 mopar engine had constant valve cover leaking was the manifold flange on exhaust was putting the headers too close and frying gaskets....but if the exhaust valves were done like the BBC or HEMI, it wasn't a problem....hense the olde original AFR/canted valve design....

so why doesn't Detroit go there???

guys talk of Vortec with taller intake runners so the older shit don't line up, WTF goes on there??? I would go Vortec in a flash IF I could get a cheep enough DPFI manifold for it, but just what does that buy over my present setup???

shit like that I never seen a succinct answer for, just snip and snaps of threads that never add up too clearly for me....

:surrender:

Detroit has gone there. LSX

As far as Vortec goes, if you want a lot of guys who are real big on Vortec...go here:
http://www.hotrodders.com/forum/

They LOOOOVE Vortec there.

HOO, boy followed that link into another about a FLORIDA lawsuit over some slicksters and their advertising practices/etc......

HOT button issue for me, as I got burned long time ago with Florida business, partners, investments, hotrods, etc......

ALL suits like that are useless waste of time/effort....I would just laugh it off, and not even bother to reply....all court outcomes in Florida are useless as tits on a bore hog.....

don't ask how I know?? OK???

LONG fucking story and I have two boxes of papers from ten years ago that prove the story.....

and the crooked BK law FEDERAL JUDGES that took the payoff and let a fraudulent BK ruling go through slick as shit.....

then some folks wonder why I hate lawyers, damn common crooks is all they are.....complete moral sluts....

:bomb::cussing: