Is there a difference? I dont own any 4 bangers but have always wanted to know.

hope i don't get this too wrong. the quad 4 was a twin cam engine developed by olds. avialable with up to about 185hp. i think it's supposed to be a little lighter than a duke and more resposive to mods. now the engine has been refined (balance shafts) but with lower hp numbers. it's the engine in cavalier z24's and similar gm cars, but i think the peak output is around 150hp now.

it's kind of something to watch because every once in a while thry'll make a concept car and put a blower on the engine and get around 250hp. also there are turbo kits with even higher numbers.

hopefully someone can confirm or correct this.

from what i've been reading you've got it right. I've been reading up on things to try to decide what mods i want to do.

The "Iron Duke" is a 2.5 liter conventional pushrod engine and was used in many cars including the Fiero. The Quad 4 is a high reving, light weight engine with 4 overhead cams and 4 valves per cylinder. The Quad 4 makes a lot of horsepower for it's size, but at the price of sacrificing low end torque. The older 2.3 liter Quad 4's also have a reputation of blowing head gaskets.

Batboy is right. Quad 4s also go through water pumps like nobody's business. The 2.4s in newer caveliers and sunfires aren'e quad 4s. They are totaly revised and I don't think have a lot of interchangeable parts. They are better motors and put out nearly 200hp with a blower. They obviously cost more but it's worth it to get one in the long run if you plan to swap motors.

BTW Northstar v8's are based on quad 4s.
If someone is bragging about their Northstar, Just use that fact if you want to shut them up.

Ok, interesting....what engines were put into 4 banger Fieros? I mean, were they all the same, or did they change any from 84-88?

Pontiaddict:

I beg to differ. While some of the Northstar's design may have come from the Quad 4, the N* is much more an evolution of the LT5 engine used in ZR1 Corvettes.
The Northstar is not two Quad 4's put together. I know the pistons do not interchange. I don't know if any other parts interchange at all.

All four cylinder engines put into the Fieros at the factory are the 2.5 liter Iron Duke. The Quad 4 was never original equipment, although some people have swapped them into Fieros. They did some changes to the 2.5 in 87 (went to a DIS ignition system) and did some more changes again in 88, but they were still the 2.5 Iron Duke. The Quad 4 engines are aluminum, not cast iron.

Batboy,

The Quad 4 engines have an aluminum head ... the block is still cast iron.

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Paul, Sedgwick, KS
88 Coupe, 88 Formula, 88 GT

I just went outside to see what I have in my just delivered 86 t-top fiero(really bored).
It says Quad 4, in big letters on the engine.
Does this mean I have a quad 4, or the Iron Duke?
Well since it's going to be a v6 or v8 swap...it doesn't really matter.
)

Hmmm,

If I had a Fiero with a Quad 4 already installed, I think I might make a visit to the General Motors performance catalog before doing another engine swap. The Quad 4 can be a real fire-breather. For those of you who may not know it, you can go down to your friendly Pontiac dealer and purchase a couple of different high performance cylinder heads (including an aluminum one)for the "Iron Duke" Different intakes are also available (4 bbl carb, and the Holly TBI manifold) Hooker still makes a header for the 2.5 (a bit pricey, I think it is around $375?)

Paul, that's what I meant, the Quad 4 has a big over-sized aluminum head.

Child of Rod, the two engines look nothing a like. Lots of the 2.5 has Tech 4 on the air cleaner. Below is a pic of a quad 4 in a Fiero and here's an URL with more info.

http://www.gigaparts.com/users/fiero/q4b.htm

[This message has been edited by batboy (edited 08-02-2000).]

Hi, I am planning on doing a HO Quad Swap in my GT. It's a 1990 out of a Grand am. I also have a 97 Sunfire GT with the 2.4. That is moded and it runs fast. As far as the older Quads, before the revised Twin Cam, now in Cavs and sunfires were known for many problems. The coil packes fail,headgaskets blow (10:1 compression), and of course the water pumps. Most mentioned above. By the way, the 1990 HO Quad I have is rated for 180 HP and 160 ft#'s of torque stock. It is easily moded and takes to the mods very well. There is place on the net called Genertec Racing, they have a 600 HP Sunfire and work only with these engines. Down the road I will be upgrading pistons and cam with a new computer, good for 225 HP out of a four cylinder. I believe with this engine in a Fiero and the the good power to weight ratio, you would have a heck of a performer.

Anybody have one in their Fiero? Would like to know how it runs in there. I'm hoping for at least a 14.9 quarter. That may be pushing it.

Eric in PA
86.5 GT