Saw this performance cylinder head on Ebay. Guy claims he had 190hp on a duke.
http://cgi.ebay.com/ebaymotors/aw-cgi/ebayISAPI.dll?ViewItem&item=421496875&r=0&t=0

Wow, at that price for the performance. I'm now thinking about going out and getting a 2M4. That's more than double the horsepower. how?

GM, I hear, still has a preformance head for the 2.5L engine. Sells for $310.00. The horse power listed is a bit high but I belive more than 150HP can be gotten out of a Duke. New cam, pistons, port and polish head (or preformance head) larger valves, Holley TBi, Holley intake and preformance exhaust header with high flow muffler and cat. After all it only takes money. For reliability a forged crank, new timing gears, rods, bearings lightweight flywheel and custom pullieswould help. After all the SD4 is modled after the DUKE. (stronger block, better componants) Kanas Racing will sell you a SD4 for about $12,000.00. As I said it only takes money.

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Peace and Happiness
Frank and his fotoflash, an '84 SE 2M4
http://fotofrank.homestead.com/fiero.html

That guy has the Holley stuff and a Hooker header for sale too !! Wish I had the cash. I'd be bidding. Hec...even 150 hp out of a Iron Duck would be real COOL !!! I wonder what all those mods do to fuel economy ? Better or worse ?

You can get a stoker kit for the 2.5 to 3.0 and if you have the SD block instead, add an over bore to 3.3 liters. Or over bore to 2.7 liters if you can't get the stroker crank. At 3.3 liters and a high flow head and cam, you should make over 200hp. Don't forget the bigger TBI injection and throttle body. With 14:1 pistons, I'm sure the hp would be closer to 300. And if you could get your hands on the 16 valve head...way over 300hp could be achieved... But then let's see you pass emissions...

superduty's are coooooool

quote Originally posted by lou_dias: You can get a stoker kit for the 2.5 to 3.0 and if you have the SD block instead, add an over bore to 3.3 liters. Or over bore to 2.7 liters if you can't get the stroker crank. At 3.3 liters and a high flow head and cam, you should make over 200hp. Don't forget the bigger TBI injection and throttle body. With 14:1 pistons, I'm sure the hp would be closer to 300. And if you could get your hands on the 16 valve head...way over 300hp could be achieved... But then let's see you pass emissions...

lou_dias:
who makes the 3.0L stoker kit?

Here is a link to a place that has ALL the SD4 engine parts! Just click on what you want. The link takes you to the rod/crank stroker kits. You can buy a street SD4 with 210hp for $9500. The only engine they sell built-up on-line is the ARCA truck engine for $13000. But if you call them up they can build the SD4 of your dreams!
http://www.gtsonline.com/krp/prod2.htm#rods

"Speed is just a question of money, How fast do you want to go!"

that webs-site only mentions a 4.125 inch bore, but I'm pretty sure the GM performance parts catalog says it can go higher or they offer a longer stroke crank (>3.5 inches)... 3.3 Liters is attainable, don't forget to shorten the piston height to make up for the extra stroke.

quote Originally posted by Oreif: Here is a link to a place that has ALL the SD4 engine parts! Just click on what you want. The link takes you to the rod/crank stroker kits. You can buy a street SD4 with 210hp for $9500. The only engine they sell built-up on-line is the ARCA truck engine for $13000. But if you call them up they can build the SD4 of your dreams! http://www.gtsonline.com/krp/prod2.htm#rods "Speed is just a question of money, How fast do you want to go!"

So does anyone know what the biggest crank is that'll fit in an Iron Duke?

Supposedly, all SD parts are interchangable with the iron duke, but the iron duke doesn't have enough iron behind it to withstand the output of the SD parts. that's the rumor anyway.

According to the Pontiac Performance Plus book, The largest crank is 3.9375" stroke
(Pontiac part # 10041860) I don't know if the GM part # is still good. Book was printed in 1985.

My math must be off. This KRP engine ... built from parts. Just playing with numbers.

4.125 diameter bore divided by 2 equals a 2.0625 radius

Volume of a cylinder is v=<pi> times radius<squared> times heighth

radius squared is 4.2539 times 3.1417 ('pie') equals 13.364 (about)

13.364 times 3.9375 inch stroke equals 52.620 cubic inches per cylinder times four cylinders equals about 210 cubic inches displacement.

that's about 3.5 liters on conversion!!!

Course KRP has this block set up for either the SD4 or SBC performance heads! That means you can get the revs up to about almost 10,000 rpm.

Good great gravy! At the 1.77 hp per cubic inch (theoretic max sustainable power output using normally aspirated Fuel injection) puts the max output in the range of 370 HP and over 400 torque! Say 70% of that so you have a durable engine that might idle without dying and you got ... 259 HP and 323 f/lb of torque. !

IN A FOUR CYLINDER???

Or is that a "vibra-bed" ???

Need to have a driver and copilot both in the 250 pound range to keep that "rocket ship" on the ground!!!

Lord! What fools these mortals be!!!

The Pontiac Performance Plus Lists the Street/Strip car as bore: 4.0 Stroke: 3.9375
Displacment as 3.0L Using Twin Holley 2 barrel carbs. Horsepower as 346 and torque as 280. It shows quater mile as 10.47 @ 126mph! From a normally aspirated SD4 carbed.
Wonder what it would do with fuel injection?

3.0 liter would be about 181/2 cubic inches

1.77 hp @ cubic inch would be 320 hp/400 torque ... but that is a theoretical (numbers only) assuming "street setup". Cam, tuning and intake/exhaust could adjust that by 20-25% either side (higher RPM =more horses but less torque and vice/versa) The engine is on the edge of design envelope and probably would only last maybe 10,000 miles.

Still a heck of a lot to ask out of a four cylinder. Especially in a "daily driver". Now for a race car ... especially a drag car this could be cool.

My 1985 Iron Duke 4 is putting out 92hp and 143f/lb (at rear wheels) with only K&N filter, Accel coil, and aftermarket converter & muffler. It runs smooth, starts immediately and allows me to outdrive all the kids in their "my stereo cost more than my car" mobiles and even hang with the 'vettes and such around my city. I have no complaints.

[This message has been edited by Tryxalon (edited 09-03-2000).]

BRAIN OVERLOAD...lol

Just get a Ferrari V12 and replace that Duck of Iron.

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'86 Special Edition,
High-Output V-6 Yellow Fiero
Special Rally Heavy Duty Suspention

quote Originally posted by Tryxalon: hang with the 'vettes and such around my city. I have no complaints.

You hang with Vettes with a I4 !?!?! Do you live in a city that has snow year round??

Wait is that Corvette or Chevette ??
lol.....j/k

How can you do that with a 4 bangger?? I have a 2M4 with only 46,000 on it (Runs Perfect) and I cant hang with anything

[This message has been edited by Haze_Performance (edited 09-03-2000).]

Haze - Yep. Hang with Corvettes, Chevettes, Merceedes 450SL, Vipers or even the one Lamborgini Diablo in town.

Seems I always catch them at the very next stop sign/traffic light !!! <smile!>

They can run, but they can't hide!!

Yeah, I'm shuckin' and jivin' some!!

I was just having some fun running numbers. My point is that a 4cylinder of that power output would loose every advantage a 4 cylinder has except weight. If you want performance like that you should put a Small block in it. That's Power!

I'm over 40 and value "sports car handling" much more than "feeling G's". That's why I have a 4 cylinder, not a V-6 or even one of Archie's v-8 kits. I like the balance of the car with a Duke and I have no need for traffic tickets or a desire to reach "escape velocity"!!

I also have no idea why someone would invest more than 10% of a car's value in an "audio system". For me that's about $200. I paid $75 for my used CD changer (and put it behind the passenger seat) and run it through the stock AM/FM Cassette radio. (just read about the guy who has stacked 5 amps in his trunk and stuck 12 speakers in the cabin??) I'm happy and having fun! - but that's my take.

I also is laboring with my 85's lack of Iron Duke power.I need more power,but do not want to add any weight.I am against dressing up a motor not intentially designed for performance. The solutions above sound intriguing and exciting to the senses. For the money spent, I suggest concentrating I high-tech. In other words, I'm looking at the Quad-4 H.O. Not to disparate the factory set-up, but advances over the years in volumetric efficiency has me convnced. I like my Duke for now. But someday...If I can find someone to help with the swap. Suggestions anyone?

There is a much easier way to figure cubic inches...
try
.7854 x stroke x bore x bore x number of cylinders = cubic inches

no real experience, but from what i've read the 4 cam 3.4 gives the best power without sacrificing so much weight. i think it's supposed to be a little lighter than a stock 2.8 (read that in a kit car mag.).

Got an e-mail from the guy with the NEAR 190hp Iron Duke. Says the bottom end was a SD 4 block and crank. Dynoed at 187hp. Right now I would be happy with more torque and about 130hp or so.Remember guys(and gals) torque is how much work you can do and horse power is how fast. If you only want to get off the line fast (read stop light) maybe torque is all that is needed.An Iron Duke no cat(unlawfull) good exhaust ported input and exhaust,timed 10deg BTDC and the Holley TBI with (check dis out) Better AIR FLOW. how much will a Ram air do on the street? Are we kidding oursrlves that "cold air "is possible on the street? I bet a dollar to a donut that more,or better air flow into our engins(L4 V6) will do more than any ram air/cold air system on the street. What leads me to this you ask. If more air is not better what are supperchargers and turbos for? Sure cold air is better to make more "speed" but we all drive in the same weather.K&N are free flowing filters butnot having a filter could be better.The single best improvment is a new cam. Might as well have that cam installed while we get the rings and valve job most of our cars need. What do you want to spend your mony on today?

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Peace and Happiness
Frank and his fotoflash, an '84 SE 2M4
http://fotofrank.homestead.com/fiero.html

Colder air is more air because it’s denser, which means more o2 gets into the motor. That’s why intercoolers on turbochargers and superchargers work so well.

What is being overlooked here, is many race cars in the early eighties used 4 cly. engines. I know my 4 banger in my Fiero5 can smoke most standard stock muscle cars.
Even a Viper now and then )

I sure wish I had your 4-banger, Fiero5...my 88 Coupe and I got our butts kicked by some kid out on a test drive in a brand-new V6 Camaro Friday night. It wasn't even close.

GM's 3.0 L engine, GM makes a 3.0L 4 cylinder engine... is that just the 2.5 with a stroker kit? would 2.5 parts fit onto the 3.0 is it the same block, size exc.. would it bolt right up?

thanx

That's a good afforndable real-world power upgrade for the Tech4... Put in the 3.0 crank shaft when you rebuild it with good quality V8 class pistons and rods and you have a clean 25hp gain in power, maybe go with the Holley intake and TB and some 1.7 roller rockers... That should be 180 hp...

what did GM put a 3.0L 4-cyl in?

super duty race cars

Does the 3.0 bolt right up to a 84 Fiero Transmition (Auto) and would the emmissions and stuff fit off the 2.5?

thanx

I have seen the 3.0 inline four in marine applications

our old (mid 80's) inboard boat had a 180 horsepower Duke in it. The Mercruiser label said that displacement was 151 C.I.- what would that engine have that a car Duke would not?

It doesnt really seem like anyone knows of the Marine 3.0 will except 2.5 parts and bolt right up to the tranny so does anyone know where i should look to find out? who to ask? books to read......

thanx alot
Kyle

Hmmm well anyways, last try.... about the 3.0 Where can you get the Stroker Kit? and if anyone knows - the Marine 3.0 engine is that just the duke with the stroker on (same exact block?)

thanx

Try your search here.
http://www.gtsonline.com/krp/prod1.htm http://www.homestead.com/fiero2m4/index.html