Di you ever get the dyno numbers on this bad boy?

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87 GT
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well I did some dyno2000 simulations as close as I could with info he gave.

I'd suggest 1.94/1.60 valves if you haven't redone the heads along with some pocket porting. Looks like it won't do any damage to bottom end power and helps a lot with mid and top and on this combo. Also happens to be the cheapest valves available being stock 350 size everyone wants.

I'd also suggest a 100 horse nitrous kit :-)
I came up with a 4.0lb a minute nitrous engine using mostly your combo that makes 300hp and MONSTER torque... how about 400ft-lbs of torque at 2500rpm... and about 300 horse 5000-6000rpms?

That's an improvement on the stock 98 horse... you did say your o-ringing the heads right? :-)

Oh, your combo...
Peak torque about 201ft-lbs at 4000rpm
Peak power about 180hp at 5000-5500rpms

assumed a bit of port work in heads, hard to determine cylinder head flow,unless you've got flow data... 1.94/1.60 valves look like they would bump numbers to about 210ft-lbs and 203hp. Sounds like an easy 20hp and 10ftlbs torque to me for the money.

If you want dyno2000 files let me know.
By the way, blowers and turbos just don't seem to help much on this type engine, nitrous seems to be the way to go.

Bump...

Any word on getting this project back on the road?

quote Originally posted by Scott-Wa: Bump... Any word on getting this project back on the road?

still waiting for the block to come back from machine shop

are you doing any port work to the head? boring out for bigger valves maybe?

Inquiring minds want to know ;-)

quote Originally posted by Scott-Wa: are you doing any port work to the head? boring out for bigger valves maybe? Inquiring minds want to know ;-)

new head has a pretty healthy port job. totally relocated intake ports. stayed with stock size valves to try to get low end torque. keep in mind, the engine will not see more than 6,000 rpm.

I have to say that this is one of the most serious duke buildups I have seen! You should be proud of yourself! I cant wait to see some numbers on this engine. Good work!

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James Essar
Co-Founder of NEO Fiero Club!
88 V6 Coupe 3.2L V6 With NX Nitrous Wet shot (100-150HP Shot)
Stock 4, Wanna Race?

quote Originally posted by mrossum: new head has a pretty healthy port job. totally relocated intake ports. stayed with stock size valves to try to get low end torque. keep in mind, the engine will not see more than 6,000 rpm.

In theory I showed a power increase with 1.94/1.60 valves from 3000rpms and up with a 1 ft/lb loss at 2000, 0 change at 2500.

Gains at 4000rpm 6hp 7ft/lbs.
4500rpm 9hp 11ft/lbs.
5000rpm 14hp 15ft/lbs.
5500rpm 21hp 20ft/lbs.
6000rpm 26hp 23ft/lbs.

Oh do you have the actual dialin chart for the cam? I used a cam math calulator to try and match the cam. The sheet for dailing it in would be more acurate.

Also do you have any actual flow data for the cylinder head? I could make a custom profile that would also be MUCH more accurate. If you had it flowed and they gave you a chart of flow on intake and exhaust at a specific pressure drop in H2O at different lifts I can get real close on what to expect.

Since I can't cut and paste from DYNO2000, I'll scan the printouts and post parts of it for you to evaluate. If you want the entire 5 pages of what I punched in for my best guess with your given info and the 5 pages with the change to 1.94/1.60 valves, let me know.

Ok, im debating the building the duke or just putting in a 3.8L My questions are probably vauge but here goes

first off what year is your car? Mines an 88 model and runs off the DIS ignition.

chevy 350 pistons will work just fine right?

chevy roller rockers will work just fine right?

will the 153 crank fit in the 88 block?

how many rpms is this engine good for?

could you pull the front wheels off the ground when it was running?

do the hooker headers add horsepower to the duke?

what about the bored holley throttle body.

matthew

quote Originally posted by m0sh_man: Ok, im debating the building the duke or just putting in a 3.8L My questions are probably vauge but here goes first off what year is your car? Mines an 88 model and runs off the DIS ignition. chevy 350 pistons will work just fine right? chevy roller rockers will work just fine right? will the 153 crank fit in the 88 block? how many rpms is this engine good for? could you pull the front wheels off the ground when it was running? do the hooker headers add horsepower to the duke? what about the bored holley throttle body. matthew

mine is 86 with distributor

350 pistons should work, but you willhave to pay close attention to compression height to get the correct compression ratio.

big block chevr roller rockers will work if you machine the head for 7/16 studs

153 crank will fit the block, with rear seal adapter, but the isn't any provision for the trigger ring on the crank.

probably good for 7,000 rpm, but i have a 6000 rpm rev limiter chip in the msd.

didn't try anything with a brand new motor. probably will not pull front wheels off ground.

the header and bored tbi are probably good choice, but tbi ,ight not have big enough injector to feed extra cubes.

hope this helps............

im also looking into the quad 4 scince ive picked up a 88 grand am for 150 bucks with a quad and a 5 speed. but its only 150-160 horse with probably 130-150FT/lbs torque, if that can hang with a stock v6 i might just swap it in.

matthew

Posts that go BUMP on the web.

...you can see pics of the engine here...
https://www.fiero.nl/forum/Forum1/HTML/019826-2.html

...and here is what was posted at the yahoo group akxsironduketech4garage...

At the Michigan Fiero Club "Fieros in Frankenmuth" show, I saw
an amazing car... and it wasn't even in the show. Imagine this...

Start with a super duty block, use the 3 liter crank. Get the high
port aluminum SD head, and top it off with the SD valve cover.
Use a full roller valvetrain. Get the biggest cam that you can
stand. Get the hooker headers flange, and use it to weld up your
own header which is connected to a custom built exhaust
system. Weld your own intake manifold and borrow a throttle
body from a 305/350 TPI intake setup. Use programmable
sequential fuel injection. Use nitrous as desired, adding up to
150 HP. Put engine in '84 Fiero Indy.

This car was amazing... I forgot to ask the owner what his name
was, but I wish that I had. He said that the first engine that he put
in this car was a SD from a racing team, but it ONLY made 230
HP. He decided in 1995 to custom build the engine that is
currently in the car. And the best part is this: he put the car on a
dyno after he built the current engine and guess what... 340 HP,
and that's WITHOUT NITROUS! He used a built up THM 125 and
the results are interesting because the cam gives the car a poor
idle, even when it was between 1-2k RPM. When he was leaving
the show, the car stalled the first time he put it in drive. He said
the engine could take up to 8,500 RPM, so I'd believe that his
power peak is probably somewhere around 7,000-8,000 RPM

What a sweet car... I was drooling.

....I would be as well if I could do that with an iron duke/tech IV. Anyone else experiment with fuel injection?

About blocks, I have been told that the old S10 pickup 2.5 is a sturdier block (same internal casting as an SD but with regular cast iron and bearing sizes). This block must be drilled for the starter since the starter is on the other side in the S10. This might be a better "budget" block to start with in building a better duke.

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Ira Crummey
1984 econo coupe
1985 coupe
The Iron Duke Resource Site

bump

quote Originally posted by TI_3VOM: ...you can see pics of the engine here... https://www.fiero.nl/forum/Forum1/HTML/019826-2.html ...and here is what was posted at the yahoo group akxsironduketech4garage... At the Michigan Fiero Club "Fieros in Frankenmuth" show, I saw an amazing car... and it wasn't even in the show. Imagine this... Start with a super duty block, use the 3 liter crank. Get the high port aluminum SD head, and top it off with the SD valve cover. Use a full roller valvetrain. Get the biggest cam that you can stand. Get the hooker headers flange, and use it to weld up your own header which is connected to a custom built exhaust system. Weld your own intake manifold and borrow a throttle body from a 305/350 TPI intake setup. Use programmable sequential fuel injection. Use nitrous as desired, adding up to 150 HP. Put engine in '84 Fiero Indy. This car was amazing... I forgot to ask the owner what his name was, but I wish that I had. He said that the first engine that he put in this car was a SD from a racing team, but it ONLY made 230 HP. He decided in 1995 to custom build the engine that is currently in the car. And the best part is this: he put the car on a dyno after he built the current engine and guess what... 340 HP, and that's WITHOUT NITROUS! He used a built up THM 125 and the results are interesting because the cam gives the car a poor idle, even when it was between 1-2k RPM. When he was leaving the show, the car stalled the first time he put it in drive. He said the engine could take up to 8,500 RPM, so I'd believe that his power peak is probably somewhere around 7,000-8,000 RPM What a sweet car... I was drooling. ....I would be as well if I could do that with an iron duke/tech IV. Anyone else experiment with fuel injection?

I personally know the owner of this "Super" pace car. I am a member of the MI Fiero club, so I am very familiar with this car. He started by building up the 2.5 Duke that came in the car with a SD head. Later on he decided to go all out and build a SD race engine for his car. This car is very over the top. All engine components are top shelf, high dollar items. His engine pulled 340 HP/ 280lb/ft while being tuned and broken in on a dyno. He runs Cal-map so he can change the A/F on the fly with a laptop. It is a port injected engine (not TB), running 12.5:1 CR, and 50lb/hr injectors. The reason he uses such large injectors is that he also has a three stage dry nitrous kit good for another 150HP. Basically he has a 3.0 liter 4 cylinder engine that can put out roughly 500 HP. He has the original TH125, but it was completely rebuilt to withstand this much engine, and he has some insane racing torque converter that has like 4,000rpm stall.

The owner is a great guy and has helped me resolve some engine dilemna's on my car.

I LOVE this thread!

Steve

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http://kelleyfamilyfieros.50megs.com

quote Originally posted by Fiero5: I LOVE this thread! Steve

Me too! I had always needed to rebuild my 87 4 cyl engine, then it died, so now id love just to rebuild it to like 200hp, but would need some advice, or help for this from someone who's done it. cant wait to see how this turns out!

Jon

car went to muff shop yesterday. still don't have intake back from machine shop. hopefully have intake back mon or tue. maybe have car running again by friday.

car is back from muffler shop. changed the stock header type manifold to a 180 degree cast iron manifold with a custom built 2 into 1 header pipe. intake is back from welder, also. works, but i don't like it. am gonna build another one. car is back together, but still having fuel delivery problems. 454 injector is not big enough. am fiddling with the fuel pressure regulator, trying to bump up pressure. car sounds GREAT with exhaust on it...can't wait to drive it.............

I have just started following this thread, I have to say It takes some Ba11s to get past the naysayers.
I am Very familiar with the Iron Duke and its design and layout problems and benifits. Other than flawed rods, a crappy crank design, and constant oil leaks (Ok, it leaks any fluid you put in it) , the Iron Duke is a decent daily driver engine.
The biggest flaw that hurts the engines ability to produce decent power, is its crank, the design of it is horrible. There is only 1 counterweight on each cylender, so at high RPM's the crank wants to distort, and starts to do so at around 5000 RPMs, it's a weak crank anyway. The stresses it puts on the block and rods cause it to blow up if reved too high. Or at least thats what I have gathered from working with a few of them. I think that if you put in a crank, any crank that has the full 8 counter weights, the Iron duke will suddenly be capable of puting out a decent amount of power.
There are a couple of cranks available. Like mensioned, there is the
1) 153 Chevy crank, I know nothing about it.
2)Mercruiser 3.0 Crank witch has a real long stroke (3.5"?) and is built to sit at revs all day long, It is REALLY good with torque. I don't know if it has 8 counter weights or not.
3)SD4 Crank, witch is a longer stroke crank as well, it has all 8 counterweights, is knife edged and has 2.10" crank pins, SBC rods and pistons actually will fit. Unfortunatly the cost is prohibitive.
I was considering building up a Hi perf Duke for my Indy, as a freak motor. Stock looking but puts out 150 or so horses. It never materialized when I couldn't find a crank.

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Matt D
1984 Indy Fiero 4sp.
1985 2m4 now equipt with a 1996 3.4 DOHC.

Here's the picture of a Merc 3.0L crank:

There are the eight counterweights you wanted. Here's my thoughts:

1986 Vin E (from Astro Van) Block
Merc 3.0 Crank
Crower Rods
Silvolite hypereutectic pistons (9.5:1)
+1 Roller Cam and Lifters
SS Stock Sized Valves
Hi-Po Springs
Full Roller Rockers
87-92 S-10 Head, Ported/Polished
Custom Aluminum Flywheel
Adapt an 87/88 Intake/TBI unit to head.
87/88 Harmonic Balancer
Have entire rotating assembly balanced.
MSD Ignition with Rev Limiter
Add a nice 6-8 PSI of boost and tune-it.

This sounds like fun. I wonder what my wife will say when I start collecting parts for this.

[This message has been edited by mshill (edited 11-12-2002).]

quote Originally posted by mrossum: turns out to be more than blown head gasket. clogged fuel injector caused extreme lean. burned 3 pistons. should be back up and running on mon or tue....

You may want to invest in a $35.00 Air/Fuel gauge so you can detect the lean condition and resulting problem before it happens. Those smallish Duke throttle bodies don't flow much fuel are quite small and don't flow all that well. The larger Holley throttle body may be necessary for a heavily modified engine. As for the 11:1 compression; I don't think that the Duke will hold it without an O ringed block. In addition where the heck are you going to buy the 113 Octane gasoline that this type of compression requires- your local airport??
Good luck on the project.

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87GT 3.4 Turbo Best 0-60 5.2 seconds
http://turbofiero.fierojoe.com/turbo.htm

car is finally up and running. 21 psi fuel pressure is what it finally took to get it to stop running extreme lean. made my own fuel pressure regulator, and used a stock type v-6 fiero fule pump. have some dialing in to get it right, but should be fast. has already stomped a 2000 mustang with v-6 and 5 speed. will post hp numbers when i get it to dyno shop.....

Good job, any chance of getting pics of this beast completed?

quote Originally posted by Bizquik: Me too! I had always needed to rebuild my 87 4 cyl engine, then it died, so now id love just to rebuild it to like 200hp, but would need some advice, or help for this from someone who's done it. cant wait to see how this turns out! Jon

I'm at a point with my 84' where I need to rebuild or replace the engine. I've been considering a swap to a V6, but this sounds pretty interesting. I would also be interested in doing something a little less ambitious than mrossum, although I also can't wait to see how it turns out. Any ideas for a 150-200HP Iron Duke?

Can you just imagine the stupid looks that you are going to see, when they find out that they just got stomped by a 4 cylinder!

I am so proud for you, I've got goosebumps!

Way to go!

jetman

that build up of the duke sounds like it was a fun project, makes me want to build my own now, thanks for the inspiration

dan

If you want a better head gasket than stock the SD-4 nes are still availible. The part number for the iron head version is 10031324. It say to torque the bolts do to 105ft/lbs and tht this head gasket does not need retorquing. BTW RP sell refurbished 3.0L marine crank for around $400.

The Stickman

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http://members.tripod.com/~TheStickman/SnTsFieros.html

i had forgot how much fun it was to drive my little hot wheel. should be able to drive it back and forth to work after this weekend. have to put the body back on and do the alignment.

quote mrossum: i had forgot how much fun it was to drive my little hot wheel. should be able to drive it back and forth to work after this weekend. have to put the body back on and do the alignment.

How many miles have you been able to put to the rebuild? Is it run in yet?

quote Originally posted by 30+mpg: How many miles have you been able to put to the rebuild? Is it run in yet?

have about 100 miles on it so far. haven't broke it in fully, so i haven't really romped on it very hard........

What is a duke? i havent ever heard of this before!

This is the sort of thing I would like to be able to do some day>

Bump!!

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Ira Crummey
1984 econo coupe
1985 coupe
The Iron Duke Resource Site

I'm hoping to have 4 dukes here by the weekend.. sounds like I may have to tear into one of them for experimentation...

Well, if this turns out good I may have to have an engine built. IF anyone in SLC needs an engine built I have a friend that owns a machine shop. Builds some of the best race engines I have seen put together.

give us a price estimate as to what the engine cost you (minus the blown engine parts)

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The fiero is now shown! Check out some of my rides:
http://shawn.ccicom.com

[This message has been edited by thegreep (edited 02-21-2003).]

quote Originally posted by thegreep: give us a price estimate as to what the engine cost you (minus the blown engine parts)

rough estimate on price is about $3500, not including the broken parts. money well spent, though..............charley