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Discussion Starter · #1 ·
Maybe you guys can help me out with understanding something. I know that there is an awful lot to be said about heads. And I dare say that I know a thing or two. But some of the basics seem to elude me. I have several questions and in my experience, its best to number them if I want each one addressed. And I do.

1. What is the deal with the factory mustang heads on the 94-95 GT's? Why do they suck so much? Why am I just better off to buy a set of aluminum heads, than fix up the stockers? I'm sure the stockers could be a lot better with some good machine shop treatment and better parts. Is there simply not enough meat on them? You go to making them flow better, and you run out of room or something?

2. I've been told by some people, that a more "aggressive" head isn't necessarily going to make the most power. Now while I can see where that might be true, they also said its all in the quality of the machine work. Ok. So with that in mind, the plan for my car is for it to just be a street machine. Granted I want a fast street machine, but I want to keep all the luxuries and maybe even add a few. So naturally I don't want the car shaking all over hell with some huge cam in it. Is that going to limit my power? Do you necessarily have to have heads that flow so damn much, that you need a monster cam? Or can you just pay a lot for awesome heads, that the machine work is so good that you just don't need a huge cam? I must admit that I'm a little confused on where the point of diminishing returns is.

3. Why do they even make heads out of aluminum? What's the advantage? Of course you get to ditch 40 lbs of weight, and that's nice. But what else? Beyond that is there any real reason to buy aluminum? It seems weaker.
 

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Factory heads just suck...port design isn't good and you need a REAL good porter to get them to outflow most aftermarket heads.

Aluminum dissipates heat faster than aluminum and they can handle more heat before detonating compared to iron.

If you have heads that flow great you wont need a big cam to make power.
 

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1. For the money spent, better results can be had with gt40 junk than stockers. The design limits what can be done with them.

2. Velocity at different valve heights plays into effect also. Ability of good flow is in port shape. In alot of the cases, the higher lift cams also raise your effective rpm range.

3. The ability to shed heat faster.
 

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Here's my opinion.
1. Cost,effort and end result. By the time you get all the machine work done, new valvetrain, ect. you're at the price of a good set heads, without the performance.
2. A good flowing head does not need as big of a cam to flow the same cfm. Ideally a custom cam will be used matching you're components , and wants together.
3.The aluminum heads run cooler, allowing a little more timing. But don't discount that weight, it will make a difference.
 

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Its 65 lbs difference.

1. Yes with about 2k worth of head porting, valves, valve job, springs, retainers, milling, etc, you can make a set of stock 87 to 95 E7s perform like an out of the box set of trick flows, and weigh 65lbs more, which means the trick flow car will be faster just because of the weight reduction.

2. If you have high flowing heads in a small ci motor, then you need a camshaft with more aggressive numbers to take advantage of that flow. If you dont want the larger camshaft, you will just leave power on the table, how much is dependent on combo.

3. To save weight, inhibit detonation, ease of machining and porting, and because they look cool.lol

Camshaft design isnt magic, its just science and more lift/duration coupled with tighter lsa produces more power in a higher rpm range, netting more power from the combo.
 

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Discussion Starter · #6 ·
Ok thanks for the replies everyone. So basically, it really is all in the quality of the machine work. Therefore, my next question might be, who makes the best out of the box heads? That I don't need a huge cam with. I want to get all the power I can out of whatever set of heads I buy. I don't want to leave anything on the table. However, I also don't want my car to shake much at all. Knowing that, which heads should I go with?
 

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For a 302 standard bore, go with trick flow 170s.

If it's a 306 or otherwise, AFR is good too.

Sent from my galaxy s II
 

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And what do you mean you don't want your car to shake? That shits awesome!

If you want a smooth cam either keep the stock One or get a custom ground one to be "quiet" and they'll use a really wide LSA to make it idle smooth.

Sent from my galaxy s II
 

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Discussion Starter · #9 ·
I just don't like it. I like luxury and speed lol. Of course its not going to be nearly as fast as a gutted car with no luxuries but its just a street machine not really much of a track whore. I want to be comfortable in it.

Is that the typical reason that people get custom ground cams? So they don't have to feel the jiggle? I always thought that custom ground cams were just being matched to the heads so that the combo was perfect. Then again, why would they make off the shelf cams if that were true...

My knowledge on the subject has a lot of holes, I'm afraid.
 

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Factory heads just suck...port design isn't good and you need a REAL good porter to get them to outflow most aftermarket heads.

Aluminum dissipates heat faster than aluminumand they can handle more heat before detonating compared to iron.

If you have heads that flow great you wont need a big cam to make power.
Typo? Lol.
 

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^Omg dude, WHO is that in your av? Sooooo hot!

Anyways, if you want good power, get a kit, the trick flow top end kits are sick, street kit is good for 300hp IIRC, and its just over $2k. A cam won't make your car shake unless its huge, and good street cam will just make it sound and perform better.
 

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^Omg dude, WHO is that in your av? Sooooo hot!

Anyways, if you want good power, get a kit, the trick flow top end kits are sick, street kit is good for 300hp IIRC, and its just over $2k. A cam won't make your car shake unless its huge, and good street cam will just make it sound and perform better.
Claudia de falchi

Google and be amazed...
 

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Discussion Starter · #14 ·
So why do they make new aluminum heads, that still need head work done? So many people will get a new set of AFR's or Trick flows and then send them straight to the machine shop. Do the head companies just leave extra meat in there so you can do whatever you want? Or are they just not all that great out of the box?
 

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So why do they make new aluminum heads, that still need head work done? So many people will get a new set of AFR's or Trick flows and then send them straight to the machine shop. Do the head companies just leave extra meat in there so you can do whatever you want? Or are they just not all that great out of the box?
I'm not sure what you're saying?

Just because they went to the machine shop doesn't mean they are being ported... They can be getting milled (more compression), getting a valve job, installing springs, cleaning up bowls, fixing bad valvetrain etc.

Not all heads have good valvetrain out of the box. But if you have good valvetrain, then there's no need to go to the machine shop. Just put whatever cam you have in your engine, and change your springs to match. Some people can change springs at home, some cannot.

And by the way, my b cam is one of the worst and smallest cams you'll find on a 302, but my whole car and shifter shakes when I'm at idle. Just to let you know.

Sent from my galaxy s II
 

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My last 5.0 combo was a stock HO short block, Comp XE266HR, out of the box Trick Flow TW 170's backed by a stock T5 & 3.73's. It ran [email protected] the first time out. The 266 cam had a slight lope @ idle(way less than a B or E cam) but made awsome power across the board! If your looking for a less choppy idle check out the Comp XE258HR!
 
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