How "fast" was this thing? I know average of 90hp/135tq, but what would a well tuned properly running one perform say in the quarter-mile. Et, Trap speeds? Bone stock of course. I'm curious.

 

I think the correct question is how slow was this thing?

Just a guess, but slow!

 

Thats why I put the word fast in quotations. Hehe.

 

I would have to guess at a very high 16.8-17.5 second range being I have only seen them with a standard trans so the lauch could be well enough to get it rolling.

 

Well, lets put it this way...

the car actually had 92 horsepower (the additional 2 makes a big difference!!), and 135lbs of torque.

They offered them in the Pontiac Fiero (the only motor that year). While this ONE engine was soley responsible for the demise of the Fiero (because of them all blowing up), it really wasn't THAT bad of a motor. Anyway, other than the hair-line fractures in the FWD Iron Duke connecting rods...

ok, I'll get off the fire issue.


IN the 1984 Fiero, the motor could be had with a 4-speed muncie and 4.10:1 gears. WITH all that mighty 92 hp and 4.10:1 gears, the 2,500 pound Fiero propelled itself to the quarter mile in about 17 seconds. I EXTREMELY doubt that an f-body with a stock Duke could even do low 17s!

The engine DID get pretty decent mind you..

In 1985, it was renamed the TECH-4, and it got a slightly redesigned TBI unit. It also then received ROLLER lifters, if you can believe that. (Some 85s were still Dukes however as it came out mid-year).

1986 was a carry over.

THEN!!!

In 1987, the engine output came up to 105hp!!! AND get this.. it came with DIS ignition! DIS ignition in an Iron Duke! Who would have thought? It also came with a torsional damper and a serpentine belt system (FINALLY!).

 

the good ole iron duke! My car was the slowest one in town when i had that motor in it. I had a hard time beating loaded semi trucks stoplight to stoplight. LOL, Im not kidding!!

:hail: iron duke

 

Well I never officially timed my car. But going from a dead stop and high revin through my 5 speed I got a 0-60 time in like 20 seconds (counting in my head while watching the needle...real accurate!)

This car is by no means quick off the line. Ive been torched by every civic in this city. I don't think Ive ever beat anyone off the line with this car.

Its all stock but I don't know how much horse power this car is pushing anymore.

Now when Im crusing on the highway ive been able to bury the needle on my speedo. Car handled well at that speed and seemed like it should stay there. Real comfortable to cruise in.

Going up hill while maintaining 50mph is impossible.

 

True, very true!!

 

My 4-cyl Camaro doesn't have a prayer in hell with my 2002 2.2 S10. And I still get get smoked by pretty much everything in the S10.

Brandon

 

so whats the quarter mile then 17.7 @ 55 mph?

 

Uhhh! Probably in the 20.0 range.

 

Well.. if memory serves correctly, I believe the two fastest Iron Duke cars were the Pontiac Phoenix / Olds (whatever it was called) and the Pontiac Fiero.

In the Fiero, you could probably run low 17s in the quarter if you had a VERY VERY bare bones Fiero, with the 4.10:1 4-speed manual, and the WS6 suspension.

Todd

 

I would agree 20 seconds with an Ion duke would be nice.

As most early 305s, I believe mine include have trouble getting 15's with 16's being more appropriate.

 

Man, it was worse than that!

In 1982-1983 the f-body was SOOO slow that.. get this.. the POWERHOUSE of the f-body line was the CFI 82-83 TransAm. With the WS6 suspension they managed SLIGHTLY better quarter mile times. The time that a BRAND NEW 82-83 CFI WS6 TransAm got was a 16.5 in the quarter mile (according the Road & Track).

If I remember correctly, the HIGH OUTPUT (L69?) 305 in 1984 managed only a high 15, like 15.8 or 15.9 or something in the quarter.

The rest of the LG4s were usually running about high 16s in the quarter the whole time.

The horsepower ratings for the f-body LG4 was 145hp from 1980 to 1984 I believe,

(1980 and 1981 Firebirds also were available with the corporate engine)

and it built up to 175hp that the last year 1987 LG4 put out.


Pretty sad if you ask me.

My stock 1997 2.4 liter GrandAm 4-door automatic runs a 16 flat in the quarter.

Man, if I could take my 1997 GrandAm back to the height of the 80s... like 89 or something, I'd be ruling the streets!!!


Todd

 

you would have to go further back then 89 ..... :hail: 89 TTA :hail:

80-84 unfortunately where dog years (except L69) LG4 had low compression weak cams coffee straw exhausts to name a few.

 

Is there any hope for the LG4? I mean every one is raggin on them. Can you get any good numbers from them?

Headers, exhaust, cam, intake, carb....isn't there anything out there that can make the LG4 have a better rep than its original days?

The reason I say this, Im getting an LG4 from a friend. (free motor, im not complaining). What kind of things can I do to this puppy to make it sing? Im planning on rebuilding it fromt he bottom up.

 

I'm gonna say between 19.5-20.5 sec at 63-67 mph. This is going by a preformance calc. of 3350 lbs w/ driver (probably a little light) and 78 rwhp = 20.3 @ 66 mph. I would be willing to help you(whoever) to swap a V8 in for beer money.

 

Course you can make good power with one it is after all a GM Product.

First off I would look up Sitting Bulls car, good mods, good results.

I plan in this order of things to replace with better stuff.
PS this has been covered lots, but I have nothing better todo so here goes.

Exhaust - Headers, cat, catback - as most people say don't get LG4 specific.
Cam - XR 256 or 262 is good
Intake Manifold - performer or Action+ or ZZ4
Heads - port and polish 416's or World S/R Torquer

And after all the IF you need more fuel change your carb.

Oh and good gears and if auto a TC would be good too

Oh ya and tracking stuff - LCA's Panhard SFC's

 

Maybe I can help. I talked to 82-T/A [Work] awhile back about extracting a little more "performance" out of my Tech 4 (Iron Duke) in my 88 S10. I have a G-Tech. Bone stock - original everything, plugs, wires, etc - 78K miles I got a 19.2@75MPH. This is a NO options standard cab S10, with a T5 and 4.10s. After a full tuneup and a few select mods (modified open element and Pacesetter header with 2 1/4" exhaust to a Walker muffler) suggested by 82-T/A [Work] - 17.4@78MPH. I could have done better with a tach though

 

Yeah, like Drakar pretty much said.

Bottom line, all that the LG4 is REALLY good for is a shell. That's about it. They made the engine to be a good reliable heavy duty work horse engine that could power the current cars of that day, provide decent fuel economy, and be emissions legal.

If you want to get an LG4 to be powerful, you have to strip everything about it that makes it an LG4. Basically, the ONLY thing I think I would ever keep would be the block, crank, and connecting rods.

I'd get new pistons (.030 or larger), a high output camshaft, all new aftermarket heads or some better performance GM heads...


Todd

 

My brother RACES an Iron Duke Fiero in the street roundy-round races at Langley Speedway in Langley, VA!!!!

The Fiero is totally gutted (and wearing 4 different color body panels) and running autocross tires, but the motor and transaxle are stock. He KILLS cars that are much faster than his for 2 reasons: He can launch it as hard as an AWD talon (bounce motor off rev limiter, drop clutch) and the 88 Fiero chassis is an absolute dream for going roundy-round. Also, he NEVER LETS OFF THE GAS! Full throttle all the way around, accelerating the whole time.

He's killed so many fast street cars it's disgusting. The fans always cheer him on in every race- they love watching that little Fiero kill fast cars.

 

Yeah, my understanding is that the 1988 Fiero suspension was designed by Lotus with some other dude named Herb Adams or something..

 

craig liberty ran a 2.5 in the 8.5 range for 1/4 mile

 

people need to get off the dukes .for the displacement it had nore horespower than any v8 of the same year,second it get the serous gas mileage.so i dont beat hondas or v8s ,so what
it cruises at 90 just fine and i can afford to acualy use the gas pedal instaed of watch the fuel gauge go down.

 

Wow, you're saving $.50-$1 every 25 miles you drive compared to the V8s.

 

Those of you with the Iron Duke should consider swapping out to the 4 cylinder Offenhauser engine. It can make all the horsepower you want especially with a turbo charger.

 

You know... I've got to be honest though... and I hate to insult anyone with an Iron Duke Firebird... but...

You're never going to get any real power out of the motor unless you blow TONS of cash. I mean... if doing something that hasn't been done before is "your thing"... then I say go for it... but if you want to hop of the performance of an Iron Duke because you're inexperienced with engine swaps and think that there's an easy way to get lots of horsepower from it... you're wrong.

You could spend about 10 grand in a total rebuild with a turbo charger on the Iron Duke, and it still won't compare to the performance of a stock 350 build with headers and a 4-bbl intake.


Unless you've got a Turbo Duke in a Grand Am, or you want to hop up the performance of one in a Fiero... then I say don't bother.


My 1984 Fiero 2m4 SE WS6 has a 2.5 Iron Duke... 92 horsepower and 132 foot pounds of torque. It runs high 17s all day long with the 3-speed auto...

I cannot IMAGINE how unebelieveably slow the acceleration would be in a third gen...

 

Hey, be different. I'd like to see what a turbo Duke would run if you boosted it to around 16 PSI, assumming you built the engine to handle that much. With the room in the engine bay, you could fit a decent intercooler in there, too. Add an alky injection kit to keep knock counts down, and turn up the boost some more. Sure, it would probably get expensive, but it would be really FUN... You could pick on stock LO3's and even some stock LB9's, I'm sure. Of course, you can kiss your economy goodbye...

Imagine to look on an L98 car's face when you keep up with him and then tell him you only got an Iron Duke.

Not that I'd try it myself, though... I already have a boosted F-body.

 

whats an offenhauser?and jow much do they cost?

 

I've never heard of an Offenhauser Iron Duke... but I do know that Offenhauser used to build Formula-1 / Grand Prix race engines back in the day. I THINK they're out of business now, which is a real shame... but they make performance parts for cars...

 

My Iron Duke Camaro burned to the ground on the way home with it the day I bought it. It had a perfect body and I was going to put a 355 in it. I was only out $150.00.

As for an LG4, I have to agree for the most part with Drakar.

If it has 416 heads, I myself would just throw in a new cam, a set of headers, cat back (I like the Flowmaster American Thunder, mine sounds great), performer or other aftermarket intake, run a NON-CC Q-Jet, and leave the heads alone.

Unless you plan to tear the motor down and rebuild it, I'd leave them alone.

 

That's the Offenhauser 4 banger I was refering to. Hehehe. They also used them with great success in the Indy cars. Saw a picture of an Offenhauser in a Model A Ford. It would be interesting to know how it performed.

By the way it was the Offenhauser 4 banger I was refering to for the turbo charging. Saw one for sale for around $8000. Of course you would have to find a way to hook up the accessories. Allen

 

So, is Offenhauser still in business? They make some of the best intake manifolds... even to this day many of their older intake manifolds are vastly superior to those made by Edelbrock...

 

this is something im trying to do until mine blows up and i put a better motor in my car. see my sig for stock & near stock times

im going the bolton route with my 84' LG4 to see exactly what kind of #s i can get out of it. there will be dyno #s and everything. so far, however, alls i have are track times for the mods ive done

 

Oh man.. of course there's hope for the LG4...

I used to own a 1982 Pontiac Trans Am.... (which is why my sig is 82-T/A). It was originally a LU5 CFI motor.. but someone had more or less converted it to an LG4. (same block and heads basically.. )

I swapped out the cam with a Crane Cams (forget which one), went with an Edelbrock 3701 intake and an Edelbrock 1405 carburetor (600 cfm).

I also removed the smog pump, installed a set of FlowTech headers... went with an electric fuel pump, open element air cleaner, free-flow muffler and free-flow cats.

I had a 3.08:1 LSD rear end in it... and a I think I did a few other things...

Anyway, I would typically run high 14s in the quarter using a GTECH, so I figure maybe it would run a consistant flat 15 in the quarter all day.

I never separated the block and heads....

engine dumped all it's oil in the parking lot at 150,000 miles (EXACTLY at 150,000... pretty weird).

 

Sure there is hope. Use forged bottom end parts and then use forced induction. Run around 25 pounds of pressure. That ought to make the car run real good.

 

Heres an interesting article that proves that the mighty Iron Duke can actually move pretty good with some modifications.

http://www.thirdgenfbodies.com/media...perbirdpg1.jpg
http://www.thirdgenfbodies.com/media...perbirdpg2.jpg
http://www.thirdgenfbodies.com/media...perbirdpg3.jpg
http://www.thirdgenfbodies.com/media...perbirdpg4.jpg

 

I scanned those pages for Thirdgenfbodies, and it's interesting reading. I believe the Iron Duke motors in our Fbody's and the one in that superbird are different. They utilized the Super Duty 2.7L motor. Different components and such to boost power.

I'd love to drive the car featured there. I know most do not like the wide body kit, but if I had the money, I'd build my bird to mimic that one.

 

You V6 and 4 cylinder guys think that your cars get like double the mileage of all V8 f-bodies or something. I would imagine a well tuned L03 f-body with chip/exhaust and 700R4/2.73s probably gets within 5 mpg of any 4 or 6 cyl 3rd gen f-body and would blow it's doors off. Mine got 30 mpg on the highway and ran mid-high 15s with chip/exhaust/open element/timing advance.

not that I hate the Iron Duke or the 60 degree V6's. they just weren't practical motors for the f-body. either of the 90 degree v6's (3.8, 4.3) would have been an improvement.

 

the 2.5 in the Actual Indy Pace Fiero in 1984 was putting out over 250 hp and ran that car to 140 mph.

 

The V6 was and IS an excellent motor... then and now.

And it was an ideal motor for the 3rd gen during those times.

The 3.1 especially was a pretty decent car for a sporty looking RS Camaro or Firebird. They ran decent times for the era as well.

Of course these are all just my opinions... but I really have to say that the 2.5 Iron Duke never should have found it's way into the F-body. I don't know what they were thinking.

Back in the early years of the Iron Duke... it wasn't such a great motor. And that motor single handedly destroyed the image of the Pontiac Fiero which in turn caused the company to discontinue making them.

(connecting rods were breaking at around ~20k miles causing the block to crack and leak oil all over the exhaust).

The Iron Duke didn't really become a decent motor until 1986 when it went to roller lifters, revised oiling and dedicated oiling for the timing gears.

In 1987, it got even better with the DIS ignition and belt tensioner.

I dunno... I've never been a big fan of the Duke. I have one right now that I'm in the process of building up. It CAN be a reliable motor if it was taken very good care of... but it's a motor that requires much more supervision than most other engines. A 305 V8.. as crappy as they were in LG4 form back in the day... (no offense, but it's true..) they were reliable as hell.. you could beat the **** out of them... everything else would break before the motor would go out.


My guess would be that a highway geared 3.1 f-body would probably get the best mileage out of all of them.

When you start going to smaller displacement like that, it ends up taking a LOT of effort on the motor to get the car going. A 3,000 pound car is a lot to move around for a motor that only has 92 horsepower. It ONLY even has 132lbs of torque...

Even the low output Quad-4s have more torque than that.


The new 2.4 EcoTec with VVT is a very impressive motor though....

 

I had a Quad 4, peppy motor, but they suck. I even raced some 84 and 85 Z-28s with them and won. Replacing head gaskets and the like every 60,000 miles sucks.

 

quad 4s are complete garbage, worthless junk motor turned down by ford, ford said they suck so you know they are crap, a freind of mine went throu 4 of them in a year and a half and the never worked right ever.gimme a duke any day of the week.

 

Quad-4 has nothing to do with Ford. It was designed by Oldsmobile.

The Quad-4 has problems with head gaskets because of the way people drive them. The later TwinCams were much better.


Even still, the earlier Iron Dukes are just horrible motors. At the first sign of overheating, the cyl heads crack around the valves...

Like the Quad-4, the Iron Duke DID improve throughout the years.

It ended up being not too bad of a motor... but they really half-assed the Iron Duke in it's earlier years.

 

i thought ford designed it and then sold the design to olds.
at least thats what the mechanic said.still its a piece of crap compared to the duke.