Interesting article on AFR 165 heads

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Interesting article on AFR 165 heads

November 05, 2006, 09:48:19 PM

Ford Muscle article on installing these heads on a stock '93 cobra.

http://www.fordmuscle.com/archives/2003/06/afrinstall/index.php

Seems a great bang for the effort.

Interesting article on AFR 165 heads

Reply #1 – November 06, 2006, 08:15:03 AM

Those look like excellent numbers for a street driven car that sees some track time. I'm diggin the 280 torque at 2800 rpm. I'd love to see what they did at 2000 RPM.

Interesting article on AFR 165 heads

Reply #2 – November 07, 2006, 03:52:49 PM

That reminds me about this article that I'd come across. I'm pretty sure those are the same heads.

Now, they went and did a bunch more than just change the heads, but still, it's quite impressive, considering that it's all with the stock cam!

Makes me wonder if the stock 5.0 HO cam is too much for the rest of the motor, and if Ford might've squeezed a little bit more power out by using a tamer cam. But my understanding of the dynamics of all that is a bit fuzzy at best.

Also makes me wonder how much could be squeezed out of the SO camshaft. A'course, I don't know what the specs are of either the stock HO or SO cams, so I'm really shooting blind here.

Yes, I wonder about strange things that nobody would ever actually do to their car...

Interesting article on AFR 165 heads

Reply #3 – November 07, 2006, 05:15:03 PM

The lift on the SO cam 5.0 is the same as the lift on a truck 5.0 cam and the SO cam is roller where the truck cam aint. The truck motors were rated at 180 HP with a same as SO liflt non-roller cam, e7 heads, different intake with LOOOOOOOONNG runners (for torque), 19 pound injectors and a batch/bank fire computer setup.
A set of 1.7 ratio roller rockers, a free flowing exhaust, HO upper and throttle body, and an AFPR (and perhaps a larger fuel pump)
would wake up an otherwise stock SO nicely. It wouldn't be a quarter mile jugernaut, but the difference would be VERY noticeable.

Interesting article on AFR 165 heads

Reply #4 – November 07, 2006, 06:06:13 PM

Magazine Dyno Testing = Maximum Homogayness :rolleyes:

They wouldn't know the sciencfic method if it jumped up and bit their nuts off.

Interesting article on AFR 165 heads

Reply #5 – November 07, 2006, 06:52:20 PM

Quote from: JeremyB

Magazine Dyno Testing = Maximum Homogayness

They wouldn't know the sciencfic method if it jumped up and bit their nuts off.

My guess is you're referring some what to the BS #'s in this quote....

Quote

The foundation for the test was a bone-stock 5.0L H.O. engine taken from a '91 Mustang. As delivered, 5.0 engines of this vintage had forged-aluminum pistons, a hydraulic-roller camshaft (see spec chart), a double-roller timing set, and stamped 1.6:1 nonadjustable rocker arms. Rated static compression runs around 9.0:1 with the stock cast-iron E7TE cylinder heads, which are equipped with puny 1.78/1.46-inch intake/exhaust valves and nominal 60cc chambers. With stock fuel-injection, this engine was factory rated at 225 hp at 4,200 rpm and 300 lb-ft of torque at 3,000.

Our test engine maintains most of those specs, with the only alterations being a quick bottle-brush hone to clean up the cylinder walls and a set of fresh rings and bearings. We baselined the freshened-up short-block with a pair of rebuilt but otherwise stock E7TE factory heads, the stock hydraulic-roller cam, stock tubular exhaust manifolds, and a Weiand Stealth dual-plane intake topped with a four-barrel carburetor. That combination developed 278 hp at 5,200 rpm and 315 lb-ft of torque at 4,100 on Westech Performance's SuperFlow 901 engine dyno.

I not buying that a swap to a carbed dual plane manifold and a 4 barrel carb as opposed to the factory EFI was worth over 50 HP while moving the peak HP and torqe rages up over 1100 RPM a piece.
All else being equal (if those numbers are somewhat reliable) how bad are the low RPM #'s on that setup?

Interesting article on AFR 165 heads

Reply #6 – November 07, 2006, 07:43:39 PM

When MM&FF did their head comparison a couple of years ago they got 245HP out of a stock HO. Only mod was the free flowing dyno headers...

Guess I'll have to see if I still have the mags to see how the different heads fared(kinda forgotten)...

Interesting article on AFR 165 heads

Reply #7 – November 07, 2006, 07:45:04 PM

Both articles have issues with having a control run and only changing one variable at a time.

In the first article FordMuscle states "the challenge then would be to bolt on nothing but the AFR 165 heads and see what results".
The testers then proceed to port the lower intake, retard the cam 4 degrees, slap on underdrive pulleys, put on a larger MAF and TB, install shorty headers and a Mac Prochamber h-pipe.

This could be forgiven if they tested the E7 heads with the aforementioned parts, but they don't.
So, does adding AFR165 heads add 80 hp to the rear wheels? No. How much? We can only guess, and that rubs me the wrong way.

In the second test, Carcraft claims the AFRs are "worth about 100 hp over a set of stock 5.0L Mustang heads on their own"
The testers manage to run a baseline test this time (yah).
But, when it comes time to add the AFRs, they go from stock exhaust to a Tri-Y pipe and from Carb X to a 625 cfm Road Demon Jr.

How much was gain was purely from the heads, and how much was from the carb and headers? I wish I knew. Also, they just give peak numbers, sans dyno-chart or table.

Interesting article on AFR 165 heads

Reply #8 – November 07, 2006, 08:07:58 PM

Quote from: Paul Flockhart;112183

The lift on the SO cam 5.0 is the same as the lift on a truck 5.0 cam and the SO cam is roller where the truck cam aint. The truck motors were rated at 180 HP with a same as SO liflt non-roller cam, e7 heads, different intake with LOOOOOOOONNG runners (for torque), 19 pound injectors and a batch/bank fire computer setup.
A set of 1.7 ratio roller rockers, a free flowing exhaust, HO upper and throttle body, and an AFPR (and perhaps a larger fuel pump)
would wake up an otherwise stock SO nicely. It wouldn't be a quarter mile jugernaut, but the difference would be VERY noticeable.

You know, I'd actually wondered to myself whether 200 net HP was possible with the stock SO cam and computer. I'm guessing that it might be within reach with the e7 heads, truck intake, and true duals, even if one sticks with the stock 1.6 rockers? Or, maybe, since the exhaust ports on most American V8s in general tend to be not-so-great, going 1.6 rockers for the intake valves, but 1.7 on the exhaust rockers?

How far could one go before the stock SO speed-density computer gets confused?

Quote from: Paul Flockhart;112206

I not buying that a swap to a carbed dual plane manifold and a 4 barrel carb as opposed to the factory EFI was worth over 50 HP while moving the peak HP and torqe rages up over 1100 RPM a piece.
All else being equal (if those numbers are somewhat reliable) how bad are the low RPM #'s on that setup?

I'm thinking that they're using gross numbers on the dyno, which isn't directly comparable to the SAE net numbers they stated for the SEFI 5.0 HO. In essence, the 278 hp is their "baseline" so to speak, which might well be equivalent to the 225hp net that the SEFI 5.0 HO produces.

In any case, I don't buy that they got a real world near-400 hp with the mods they made, but if you compare it relative to the baseline, I guess it's fair to say that you could gain 100 horses, or nearly that, with the changes they made.

On the other hand, AFR themselves did a more real-world comparision here, which indicates a gain of 46 horsepower, which I assume is at the wheels rather than SAE net, given the really low numbers they have. The first test with the 46 hp gain also is just swapping the heads and absolutely nothing else.

Interesting article on AFR 165 heads

Reply #9 – November 08, 2006, 08:18:02 AM

Quote from: King V

You know, I'd actually wondered to myself whether 200 net HP was possible with the stock SO cam and computer. I'm guessing that it might be within reach with the e7 heads, truck intake, and true duals, even if one sticks with the stock 1.6 rockers? Or, maybe, since the exhaust ports on most American V8s in general tend to be not-so-great, going 1.6 rockers for the intake valves, but 1.7 on the exhaust rockers?

How far could one go before the stock SO speed-density computer gets confused?

I think 200 net HP is attainable WITHOUT the truck intake.
The SO flat tops with E7 heads actually makes for a slight bump in compression ratio (I believe it's .4 or .5) so that right there with the better flow characteristics of the E7's at higher rpm's as opposed to the E6's should account for a decent gain. 1.7 ratio roller rockers on both sides of this setup would be fine. The Explorer cam is somewhere right in between the SO and HO performance wise (Exploders need torque 'cause they're fat) and the 1.7 ratio rockers would put the SO cam pretty close to an Explorer cam with the stock 1.6's. Shorty headers, a good flowing h-pipe and an HO intake manifold with some mild porting on the lower end all put together with a 60 mm throttle body.

The stock SO computer should handle that with ease. You wouldn't need to step up to a bigger injector. An AFPR set to about 10 pounds over the stock pressure would be just about right with the 14 pound injectors. You'd need a bigger pump though. The SO pump is rated in at 65 LPH and is pretty much maxed out at the stock fuel pressure with the 14 pounders.

Interesting article on AFR 165 heads

Reply #10 – November 09, 2006, 08:41:23 AM

I've been thinking about after I get my transmission redone slapping on the mustang heads on mine just for the time being until i get the new engine one of these years. That would be my last step for the mid-HO conversion and after reading this its really starting to sound worth it.

Interesting article on AFR 165 heads

Reply #11 – November 09, 2006, 12:24:27 PM

Quote from: JeremyB;112221

Both articles have issues with having a control run and only changing one variable at a time.

In the first article FordMuscle states "the challenge then would be to bolt on nothing but the AFR 165 heads and see what results".
The testers then proceed to port the lower intake, retard the cam 4 degrees, slap on underdrive pulleys, put on a larger MAF and TB, install shorty headers and a Mac Prochamber h-pipe.

This could be forgiven if they tested the E7 heads with the aforementioned parts, but they don't.
So, does adding AFR165 heads add 80 hp to the rear wheels? No. How much? We can only guess, and that rubs me the wrong way.

Isn't there information out there about how much HP the larger MAF, TB, headers and H pipe would bump? And you can't install freer flowing heads without removing upstream restrictions and expect real results. They were just port matching the lower intake, so I think that is valid. That is required to see the potential of the heads.

You don't have to port the lower Cobra intake to the GT40 heads because they are already matched.

Interesting article on AFR 165 heads

Reply #12 – November 09, 2006, 01:00:15 PM

Quote from: xjeffs;112515

Isn't there information out there about how much HP the larger MAF, TB, headers and H pipe would bump?

Probably...somewhere. Can you find it? I can't.

Quote

And you can't install freer flowing heads without removing upstream restrictions and expect real results.

If you say so.
"Real" results depend on what the goals were for the test. In FordMuscle's test, they stated explicitly they wanted to slap on the AFRs and see what the gains were. However, as I pointed out earlier, they had no baseline to compare it with...rendering their test moot.
Don't get me wrong, I'm a fan of AFR heads, but the utter disregard for the scientific method the testers show is disconcerting. It sounds like you could stand to read about the SM too.

Interesting article on AFR 165 heads

Reply #13 – November 09, 2006, 02:52:54 PM

Quote from: JeremyB;112525

Probably...somewhere. Can you find it? I can't.

If you say so.
"Real" results depend on what the goals were for the test. In FordMuscle's test, they stated explicitly they wanted to slap on the AFRs and see what the gains were. However, as I pointed out earlier, they had no baseline to compare it with...rendering their test moot.
Don't get me wrong, I'm a fan of AFR heads, but the utter disregard for the scientific method the testers show is disconcerting. It sounds like you could stand to read about the SM too.

I can see your concern. What's SM?

Interesting article on AFR 165 heads

Reply #14 – November 09, 2006, 03:10:53 PM

Quote from: xjeffs;112532

I can see your concern. What's SM?

Scientific Method. I shouldn't have put into acronym form.