I've never seen a truer statement. Jayson has made MTI successful because he realizes that to keep his doors open, he can't spend an extra 20 hours on a set of heads to get a few extra cfm. There's just no payback. For really small shops with low overhead, it may be a different story. In this day of kickass CNC ported heads, it's hard for the hand porter to compete (from a cost standpoint).

 

Visceral...

Whats with the constant "negativity" concerning myself and our product? It's getting quite old and your agenda here concerning posts related to our product is painfully obvious. Does someone at AFR owe you money or something?

What are we arguing about here anyway? The AFR is a good piece as you have pointed out. It consistently puts down above average results and does so in many different types of applications, from mild to wild and anything in between. I think the continued release of independent results being posted in the dyno section certainly help to reinforce that.

Did I take an approach in designing this particular cylinder head that is inline or parallels some of the recent discussion within this thread?....You bet your butt I did and the results of this design seem to be very effective out in the real world, especially concerning dual purpose vehicles like most people on these boards are driving.

Have I ever commented that low and midlift flow coupled with a small runner is the "end all" of this design and assures everyone the highest power curve? NO way....Good luck quoting me on that one. Have I commented that it is part of what makes the AFR an effective piece....Yes...with a capitol "Y".
Peak flow is obviously important but it is not the "end all" either when it comes to an effective cylinder head design and ultimately producing power . A combination and a fine balancing of ALL the varibales is what makes a cylinder head truly great....and then again, that cylinder head might only be truly great in a certain application and only "good" perhaps in another. What AFR has done is create and build a "real world" street/strip head capable of being bolted on out of the box and laying down the numbers....consistently....that is the key and worth the price of admission all by itself. There are certainly other good heads out there and some perhaps better suited to a particular application, but for the money, the results and consistency the AFR heads provide is tough to beat....especially in a "production" type of environment. I have flowed enough "LS" ported castings to make a judgement like that. How many have you had the chance to personally flow, evaluate, and thoroughly look over?

Sorry if I "offended" you with what you refer to as over "generalizations"....I try to be as informative and straight up as I can (on this board and others), although I'm sure some of my genuine enthusiam regarding our product might be misconstrued....especially if your an obvious fan of someone else's product.

Tony M.

By the way, regarding your dyno results, I was going to make a few of the same points Tucanare and Brett had touched on....big disparity in some key areas of cylinder head flow and a cross section not properly sized for the RPM and cubic inch you were running. Also, the AFR being CNC'ed would have had the obvious benefit of being very repeatable from one port to the next....much tougher to achieve the same consistency by hand which could have skewed the results a little as well.

 

Tony, I agree with you 100 percent, your goals set for your heads and what you are trying to achieve with them is right on the money. The original problem was that He thought his motor was down on power because they didn't flow 320 @ .600 lift and were 20 cfm down, but his overall numbers weren't bad except his .200-.300 could of been about 10 cfm better for that head. What I see here is a valve with very little if any back angle on the valve, I've seen this a lot on these LS heads where people want that big top number and don't care about the lows and mids, in this case those are his low to mid numbers. I had a cnc ls6 bought to me about 6 months ago that flowed 319 compared to my 304 @ .600, but my .200-.400 was almost 15 cfm better than his and it only passed by mine @ .540 lift. that curve was useless to me for any cam but he just wanted to show me how much his head flowed , Guess how he did it....about .010 back angle on the valve. This is so typical of how people market these days, People think just because it flows 320, regardless of where it flows 320 at, that there getting a better head. you and I know Tony that that's the furthest from the truth

 

From my previous post alone:

Now...in reference to your salesmanship, I guess I havent said anything really nice. It doesn't bug me that much either... it's just a great opportunity to light a fuse.
Apparently it was connected to some big powder kegs, huh?

And I don't dispute that it puts down better than average results, consistently. What I do dispute is the quality of the "average". I think that there are a great number of sh|tilly done heads out there. I've owned my fair share. What you are not doing is showing how your heads compare to really well done 241, 243, 317 and 5.3 castings. While you say that your heads are an excellent value, last time I checked, it was $2400++ to get into a set of 205s set up with .600+" springs, decked to your spec, etc. Since I have a 387 all bore, imagine what my choices are, $$$ wise, for AFRs?

The only company that I am familiar with first hand that I will throw up against these AFR castings is the reputedly evil TEA. For the same price as a set of AFRs set up for your application, what can you get from TEA? I submit that you can get a product that makes the same or better power than the AFR. Granted, if money is no object, then of course TEA does it's own AFRs.

AFRs are good, I'll say it again. But they are not King of All Seen, and conveniently pointing towards 28" low and midlift flow numbers just tweeks me. There is SO MUCH more to making power. I have shown in fact, as have others, that cams spend SIGNIFICANTLY more time during crucial piston events open more than .500". Pointeing at the dyno numbers on this forum is also dangerous. Historically a vast majority of heads/cam cars perform WELL under what is typically posted (to great fanfare) on this board. This board has routinely created unrealistic expectations for many starting out in the hobby or who have very limited financial means. So its safe to say that parading around 1 or 2 cars a month with good results, and comparing them to the average heads/cam car, is in my opinion a slight dis-service to many.
I know people have been asking for apples-to-apples comparisons for a long time, and objective ones at that... but we havent gotten any. Until someone takes a $2600 set of AFR 205s and compares them obectively with all the same items on an engine on a dyno to a set of $2600 TEAs set up for that engine, what I see is a mass of overwhelming sales marketing.


Sorry I seem to "one sided".... I don't think all others feel that way.

 

Visceral, I think your being a little tough on Tony, I don't remember seeing anything here where he claims that low and mid lift is the end all for heads, but I'll tell you one thing for sure, it's far, far, more important than you think. Like I said in my early posts, Even the 750 H.P. 9300 rpm winston cup motor lost power when we added 20-35 cfm up top but sacrificed 6-7 cfm in the lower lifts, That's facts, weather it offends anybody or not. Our motors constantly evolved and made more power year after year using this as our basis and the dyno back it up....everytime....Mr. Roush wouldn't of had me changing the heads to these designs if we weren't making more power, not in a business as competitive as nascar, in fact in almost 10 years working with that head the ports kept getting smaller, the high lift flow kept coming down and the low and mid lift kept going up, and that was on all the v-8 programs, not just nascar. Take it for what it's worth, I'm just putting out info here !!

 

Tucunare,

I'd love to hear some camshaft stories with these motors. Do we have to wait till another thread?

 

Sportside, now we're talking some real long threads I don't really want to get into. We're talking about hundreds of cam swaps, 2 degrees here, 2 degrees there, moved centerlines matched with those changes and then rocker arm swaps, int., ex, and then both. and then if we saw a trend for an rpm range we we're looking for then we would get into manifold swaps. short runner, long runner, big plenum, small plenum. and after that you'd move the band around with headers, short primaries, long primaries,and pipe diameters. So you see the amount of potential combinations you can get into, To get all of them perfect for all the differant kinds of tracks has got worse odds than hitting the lotto, but that's what went on every single day, always looking for that consistant gain that you can call your new baseline. if I tried to relay those stories my fingers would be numb.....and I'd get nothing done

 

Of course I am. He makes it sort of fun... and someone has to be as well. As long as we keep it non-personal (we have, I think), a good debate is good for anyone here. I've said it before... We are very lucky to have BOTH TEA and AFR making heads for us. Competition is very healthy, and a choice is nice for folks. Having people seperate into "camps" probably isnt healthy in the end... but mature people will handle it if it comes to that.

Im glad you are here sharing info with us. There are, strangely, a limited number of header and intake configurations for us. If we wanted to do a big "Power Off", we could take a AFR 205 headed motor, and a TEA whatever headed motor, and put 8 or 10 of the most popular camshafts in them on an engine dyno. The information, as objective as we could make it, would be infinitely valuable to all these people out here. I think we could probably persuade TEA and AFR to let us borrow a set of heads and then get some folks around the boards to let us borrow cams for the test. Find a sponsor to throw in the motor on loan, and we would have ourselves a hell of a test. Make it an LS6 intake and a set of Kooks 1 3/4" LTs, and noone could claim we werent working for the masses.

Unfortunately, as we have mentioned, there are so many factors in making an engine perform that you never *really* know how well something will do until you hit start and get on the throttle.

 

Visceral, I hope you didn't think I was suggesting that kind of testing, no one possibly could afford that, or the time. I was just saying that I didn't want to open up another can of worms getting into a cam thread, too many variables to consider.

 

Brett, just when I was gaining respect for you, you go and post this.....A little milling will get you a couple of points of compression ?????? I sure hope you meant a little milling will get you a couple of tenths of a point !!!! these chambers take approx .007 to gain 1 c.c., if my math is close I believe it would take about 5.5 c.c.'s to gain one point of compression so that would take roughly .040 of milling. To get 2 points of compression your looking at approx .080 of milling, I don't think that would fall in the parameters of "A little milling" And then "some" porting would get you 75 cfm. I'm just gonna throw my grinder away and send my heads to you. Please redeem yourself quick and tell me you were Joking, if not how much does a little work cost ? Because I'm gonna start outsourcing.

 

LMAO! The line forms behind me.

 

Bret didn't mean the "Little bit" comment literally. He might have been on the phone with me when he posted that lol I much rather weld chambers than angle mill that much off a set of heads though

 

Wow, just came across this thread....

All I can say is there is some really good information in here. I'd like to thank everyone who has participated thus far.

Tucunare I do have a couple of questions for you though. Up the thread a ways you indicated that you don't agree with sending your flowsheets to a custom cam grinder to generate cam profiles.

I'm just curious in your testing that y'all did, if you saw no benfits in trying to match the characteristics of the lobes rate of opening/closing, etc... to the characteristics of the port itself?

Do you have a recommendation/formula/whatever for how you would determine the type of lobe to use, or the duration to use versus say desired RPM.

You mentioned you really only care about the flow sheets to look at I/E %. The same question applies do you have a recommnedation of a formula you use to make those determinations based on I/E%.

If you have any other info to share on cylinder heads I for one would certainly like to hear anything else you might have to add. I do agree with you and Brett and Tony that keeping velocity up is the way to make power by helping to fill those cylinders. It much the same with cams though, you can prop the valve open to help crutch a poor flowing head. In the same way you can open a valve for too long (or from what we see in the Ls world at the wrong time) and slow down airspeed thus effectively killing velocity again.

Just wondering what your thought are. Again, thanks to everyone for your input....

 

Cylinder head specs are very important for designing a correct camshaft profile...

So is the application, the RPM range, power level and a host of other "items" that are not mentioned here...

Then again, I'm a bit biased on "that" viewpoint...

Ed

 

I'll just be very brief here, if you've carefully read these posts without skipping through you'll have already seen my points. So I'll make one more example. The guy that works here has a 2002 vette, it's a stick car with an LS1. We re-worked his heads and changed his cam. He didn't want anything to lopey that would make it less driveable. I believe the cam is around 222 Int, 226 ex @ .050 and .585 lift. we already put in a cam in another car that was well in the 230's @ 590 lift but it was pretty radical sounding ( actually it sounded real sweet ) but it was a little much for what he wanted as this was a daily driver. Now can someone please tell me that with or without any porting work that the bigger cam would have worked for him, NO WAY ! and as far as the gentelman with the car with the big cam that just cared about the top end power and was willing to accept a little less driveability, would he have still put in the same cam for him if his heads were stock or ported, ABSOLUTLY ! Both Guys got the sound, driveability and power they were hoping for and are extremely happy. Had I sent the head specs to the cam grinder the characteristics of the cams for what they wanted would not of changed. Those flow numbers we all see are not what the head flows on a motor.....again ....a flow bench is a tool for measuring net gains and losses. We are simply measuring the restriction at 28" of water so we have a baseline to compare. Weather those two example cars had stock or ported heads , good low flow or bad low flow, good high numbers or weather the flow fell off the planet at ..500 lift, any of those flow disparities would not of changed the characteristics of either cam, the power curves would remain the same and the driveability would remain the same. Like I said before, Pick the cam for what you want the motor to react like for your driving needs, the flow numbers are NOT going to change that.

 

I will respectfully disagree...

Matched parts will always perform better, meet and maybe even exceed a customer's goals all while providing less problems than something just bolted in...

Not eveyone wants all top end power in exchange for bad driveability. Not everyone is happy with "good enough" power levels. I've show it time and time again where a "matched" bill of goods will give the best results.

What this example you provided us reminds me of, is the drag racer that said he used all "mail order" parts and the car flies. No need to custom build anything.

I always ask, "How do you know if it wouldn't be even faster, if you chose the parts properly?"

I'm sure "Mr. Rousch" would expect the same.

Ed

 

Apparanty you didn't read the post about the cam curves with differant heads , Your dead wrong....Mr. Roush would agree with me, we saw it over and over. and please to group our cam selections with mail order engines. your only insulting yourself by by taking it to that leval. How many cam and head tests have you actually performed on the dyno. ????

 

OK... If you say so...

Let me see if I have this is correct...

It's your opinion that cylinder head characteristics do not play a role in camshaft design or configuration? Only the overall pwer requirements of the engine.

Well, this is not what I have seen in the real world. Different cylinder head characteristics require different camshaft parameters just like different "applications" require different pieces. They go hand in hand.

I really didn't think this was that hard to follow...
The "level" I was speaking of was in when "shelf parts" are being used in every application. Yes they do work to a point and the people running well with them will tell you this. If a person wants to optimize their particular combination over that point, is where a "designed" package will show it works better.

Reread what "I" said and then you'll understand the analogy...
Enough where I know the facts and can see trends in using certain combinations over others. That's why I do things that way, it works!

Ed

 

Boy, you sure can take things out of text and twist my words around. I never ever said that matched componants are not better. How do think we made 840 h.p. with a 358 cubes in craftsman truck. Why don't you soak in a little of what I'm posting instead of spouting off. So let me get this straight, You send your specs to the cam grinder, say a mild ported LS1 heads. Now he's gonna grind you a cam matched to your specs without knowing what the hell you want to do. I'll gaurantee the first thing they're going to ask is what are you doing with the car, is it a stick , automatic, street car, drag car, road race, truck pull, is it heavy or a lightweight chassis, maybe even hill climbing. there's an endless amount of camshafts out there that are perfect for the application for which the motor is being used, I mean drasticly differant, Your trying to tell me that matching the cam to the flow numbers is anywhere close to the importance of matching it to the rpm band. Let's make this real, real, simple for you to understand. Back 15-20 years ago when Super stock couldn't port heads the flow was miserable compared to what they can run today. The big Pontiacs of super stock L and K had friggin horrible heads that flowed less than 250 cfm and were all spent between .450-.500 lift still ran .780.-.820 lift cams. Now what cams would they have recommended to you if you sent them those specs.........Hmmmmmmmmmmmmmmmmm.

 

Spouting off? Not even close...

Let me quote you...

Why does providing the flow numbers on a cylinder head iritate you so much that you post this??? Makes no sense!

You allude to everyone that it is a waste of time (in another section of your post) to change the camshaft design in regards to ported vs unported heads...

Well, anyone that runs in a restricted cylinder head class knows what to do and it sure isn't what you state later...

Like I said.... knowing what the heads flow will tell the designe the correct direction to follow. Sure "is not" going smaller in the example you expressed!

At least we can agree on this comment you made...

This appears you actually agree with me where the cylinder head "characterists" ARE important!

No.... I NEVER stated that...

Now who's actually twisting the facts???

I spoke of a properly MATCHED series of components. Each having their place in a camshaft design. Let me repeat what I posted for you...



See.... You are just now stating what I had previously posted...

If you read what I wrote, you'd see that I stated this FACT already. However, I am not the one who blindly stated that cylinder head flow numbers were not important, as you did.
Again... I NEVER said that so please re-read what was actually written.

If you have the extra time, look at just a few of the items asked before designing a profile..

Cam Form

Not just the "flow figures" are asked for... though they are one parameter requested.
Boy... that's a bit condescending from someone who hides behind a screen name...
Sorry but you're preaching to the choir...

We ran NHRA Stock and Super Stock for many years before the "porting rules". Coincedentally with a 400 Pontiac. Got completely out of the rat race because of the whole NHRA "index" BS but that's another story...

We had run plenty of camshafts through those engines looking for more average power... And we DID flow test the heads and use the data to make decisions. before and after stealth work. It made a difference...

Too bad you choose to hide behind a screen name. Would have been fun to swap some stories but I think that time has passed since you feel you must be rude to be heard. I really think we're on the same page on this but it is that blanket statement that the cylinder head flow characteristics are meaningless is where I believe we will always totally disagree...

Ed