e6/e7 heads and torque

[1990LTD]

I see mention made of E6 heads having a high-swirl design, supposedly for making better low rpm torque?

I'm confused.


Am I misunderstanding something? Why would E7s be preferred to E6s?


I don't want to buy new heads if I'm going to need to wind it up a lot higher to make use of them. I don't really have any plans to put the car down a 1/4 mile.

[1987cp]

They both suck. End of story.


Actaully, not quite. E7 heads are generally thought to have a little more performance potential in stock form than E6s, since the latter's high-swirl chambers basically consists of a bunch of avoidable valve shrouding. Look at pics of each chamber and it'll become fairly obvious. As far as port design, I doubt they're all that different, especially as E7s were scarcely changed from D8s (or possibly even earlier?) except for details like chamber size. And no, you don't have to wind the wee out of an E7 to "make use of them" ... some of my favorite message-board reading from the past few months involves guys' claims of seriously huge "race heads" and making streetable power with a glass-smooth idle.

If you do get E7s, make sure you get them really, really cheap. There are those who claim that rebuilding ANY factory head is a complete waste of money.

[pantera77]

e7's suck. e6's suck alot more. When I did nothing else but swap the heads on my 91 to free, unknown condition, e7's, I noticed no difference in low end torque, and a slight difference in the mid to high range. Granted I only drove it for about 50 miles.

But, with my wagon, that has e7's and a different cam, it is dead as a rock under 2 grand.

If all you want is a stock dd, just throw an HO intake on your lopo and call it a day.

[1987cp]

But, with my wagon, that has e7's and a different cam, it is dead as a rock under 2 grand.

Must be a cam that doesn't like what you're doing with it ....



I guess we also forgot to mention that E7 heads are hugely popular for porting, though to folks who say rebuilding them stock is a waste of money, apparently porting them is an even bigger waste of time and/or money. A certain guy on another board likes to say something to the effect of, "Stock 302 heads make stock 302 power. Stock GT40 heads make stock GT40 power".

[zoomie]

Must be a cam that doesn't like what you're doing with it ....



.

actually it is the way the cam is designed crane 2020 dont make any power until 2k

[1987cp]

Oh, the 444211, the one that's supposed to make sick torque from idle to 5000. That cam has been annoying me every time I drive my car for the past four years. I've been experiencing a pretty soft bottom end and awful fuel economy with it, at least with stockish crap up top. It'd be interesting to try it again if I get some decent heads (and actually degree it this time) and/or toss it in my 351, though the SBFtechers' rule of thumb is to run a stock HO cam unless going custom.

[1990LTD]

somewhat stupid question: anyone have a dyno sheet for a stock 5.0 ho?


& do you lot think there would be a difference down low (idle to 2k) with the E7s? i'm new to this stuff, sorry

[1987cp]

I'm sure back in the day someone must have dynoed an '86 Mustang GT back to back with an '87 Mustang GT ...........

[1990LTD]

I sure as fuck don't want to get into rebuilding heads. If I find a set of E7s for cheap, I'll get 'em.

If I can't find E7s - My current heads are operating just fine - Would I still have gains from the bigger injectors/cam/ECU? and the intake/tb/etc of course

it makes sense that more fuel and more air = more power but there might be something I'm missing here. Who the hell do I listen to? I get people telling me to leave everything except the intake, and I see people telling me to do the whole HO swap.

I want to do the swap to learn how things go together, and to get a bit more power out of my car but the attitude of some tells me there's no point.

[1980c10]

It depends on what you want the end result of the car to be as to which route you will go. I like the full swap myself that way you also get rid of the junk lopo bottom end and have a little stinger engine to play with. You will definetly want gears if you go with the H.O. Stock 3.08's and the ho cam are a bad combo IMO.

[1980c10]

Also do yourself a favor and stop looking at parts for low end torque. You will end up with a turd of a motor than makes poo for horsepower and falls on it's face at 4k. Let it breathe it's what it wants and needs. Unless you like your car to run like an old farm truck of course.

[1987cp]

What's wrong with a lowpo bottom end?

[Southern_Pride]

I happen to like my e6's. My car has zero bottom end power, but the gears make up for it. Passing is possible in OD, I get 16 on the highway on it runs lean with my 650 dp. It's not a normal or sane engine combo by anymeans, but it works for me. It falls on its face by 5000 or so though. I'd keep the e6's. But I'm the only man on the planet of this opinion.

[gadget73]

The stock E6 heads don't breathe at higher RPM. There is a reason the 86 Mustang is rated 25 hp less than the 87, and almost all of that is the heads. The upper intake is somewhat more restrictive, but thats not all of it. Ford quit using the E6 heads on trucks after 1986 too. Trucks don't spin high rpm, and they had something pretty close to the lopo cam but they came with E7 heads for the extra power they can make. They're still not that great though. If you really want to change heads, you'd do well to find something better than an E7 if at all possible.

[1980c10]

What's wrong with a lowpo bottom end?

Nothing, just mustangs got forged parts from 90-92 if I'm thinking correct on the years.