I'm trying to put together a list of performance parts for the 2.5L Iron Duke/ Tech 4, with a list of what it is, how much it costs, who sells it, and where to get it. So far I have
Some great info here: http://mywebpage.netscape.com/fierost4rsc/fierost4rsc.html Alot of the parts mentioned say where they are from, but not how much they cost. Particularly interesting are the hooker spuer comp headers and Crane Roller Rockers. Anyone know how much these cost, or where to get them (when I enter the part numbers at the sites, they come up 0 results found)?
The main reason I'm compiling this info is I'm thinking about rebuilding an 84 Duke, bored .030, as well as porting, balancing, etc. Ultimately I'd like to get 130-140HP (or as fast as a stock 2.8L) naturally aspirated, also beacuase I don't think the duke could take much more reliably.
If anyone has anything to add, please post. I'm also looking for -Crankshaft -Connecting rods -Pistons -Piston Rings -Spark Plugs -Valves -Valve Springs -Any Bearings
If anyone has any experience with any of the above parts, feel free to add the pros/cons of your experience with them also.
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05:02 PM
PFF
System Bot
Avery Montembeault Member
Posts: 392 From: NIskayuna NY Registered: Jan 2001
For all of the money you're looking at spending, why not put in a bigger engine? 4.9, 3.4, 3.1 would probably be in the price range you've listed. Not bashing you; just looking at the dollars vs. gains.
For all of the money you're looking at spending, why not put in a bigger engine? 4.9, 3.4, 3.1 would probably be in the price range you've listed. Not bashing you; just looking at the dollars vs. gains.
Good Question! Lets see
1. I think it would be great to get as much HP out of the duke to keep up with the 2.8's, and still retaining the stock look of the 2.5L. This would be great for Pace Cars that still want to look like a Pace Car, but perform like a GT or Formula. Nobody expects the duke to be as fast as the V6 Plus bragging rights, you can say you have one of the fastest dukes.
2. Cost
V8 Archie Complete kit: $3250 Small Block 350 For the sake of argument lets say $500 = almost $4000 for ~400HP?
The mods I've listed so far = $1400.85 so far, maybe $2500 when all's said and done? For 130ish HP BUT on a college student budget, which limits it SEVERELY. The exhaust components can all be added one at a time of the course of time, buying one thing at a time, and you can still use the car as a daily driver, whereas the V8 swap you have to have everything right there, dropping all the cash at once.
SO the cost per HP isn't as economical as putting in a V8 ("dollars vs gains"), BUT when the budget is half the cost of putting in a V8, it makes more sense. Plus the greater Fuel economy of a high-output duke VS a V8.
It would also cost $1500-2000ish to put in a 2.8L, and I'm not sure how much it would cost to put in the other V6's, but I can't imagine it being much less than $3000.
I looked at that Crower Site, and although they don't have any Duke-Specific parts, they do custom stuff, but I don't know what numbers they would need to make say a custom crank? The crank and connecting rods are the two big items I'm trying to figure out, since the three weakest points on the Duke seem to be
One part that really interesting, a Mercruiser 3.0L Crankshaft, sold by H+M Performance for $178 + $60 core charge.
I sent Fierobsessed a PM on what he thought about the Mercruiser crank, since he mentioned it in the thread 'big bad duke'. I got this reply back:
quote
Wow, Never got a PM for a responce I made a year ago! Thats a first! Anyway, to answer that question. The 3.0 Merc crank has the same bolt pattern as a SBC not only on the block, but on the crank as well! So there would be a decent amount of machining right off the bat to get the crank first down to the stock size on the output of the crank, then it would need to be drilled for the new smaller flywheel pattern. Since I never obtained a Merc crank, I never had the chance to see if indeed the clearances in the block around the crank were sufficient to clear that massive pair of counterweights swinging from each cylender. I also don't know if the rod journals are 2.000" or 2.100" Because the SD4 has 2.100" and the stock duke has 2.000" and the merc is somewhere in between those, Im leaning toward the 2.100" The good part about that is that Small Block Chevy rods can then be used to build that bottom end up. They would only have to be narrowed to fit the crank properly. Thats not too hard to have done.
I do not know anything else further then that. I really think that the engine would be able to take some really respectible power with that crank and a good set of rods. BTW, The deck height on a 2.5 is 9" the bore is 4" IDENTICLE to the SBC's! So in reality you have a world of aftermarket at your disposal that you may have never known existed.
SO the crank could possibly be made to fit with some machine work, but I have no idea exactly what that would involve, or the umbers I'd need if I were to take a Merc crank to a machinist and tell him to "fix it!" Though this crank seems to show the most potential. Though the only other duke cranks I've seen are the Fiero Store's refurbished units, which would still have the stock crank's limitations.
[This message has been edited by RWDPLZ (edited 03-03-2004).]
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05:54 PM
Tugboat Member
Posts: 1669 From: Goodview, VA Registered: Jan 2004
How about transplanting one of those 3.0 outboards? 225 HP!
With half the stroke, 1.8" plus a 5.7" SBC rod, you'd have 7.5", 1.5" short of the deck. 350 pistons are 1.560 deck height, so you could cut them down a bit and be ready to go! The block may be a little taller anyway.
GL
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10:37 PM
fieroturbo Member
Posts: 1085 From: Orefield, PA Registered: Jan 2003
My cuz has a Regal 18' boat with a Mercruiser 4 banger, and I think it's 3.0L. If it dies, I'll let you guys know.
Some things to add to the list:
The parts selection from Kansas Racing Products
MSD's Adjustable Ignition (add's what feels like a small shot of NOS)
Denso Iridium Spark Plugs. Reduces the chance of detonation, and runs the motor cooler.
Low temp thermostat (and low temp fan swtich for non-88's) is a BIG help. The motor runs sooooooo much cooler with it.
Greddy E-manage ECM piggyback module, or the unit that West Coast Fiero's has (which may be easier to install, but not as effective).
Del West Titanium Valves and Retainers, with bronze valve guides. It's weird, but bronze and titanum have the least amount of friction than any other metal combination (i.e. Steel/Aluminum, Steel/Bronze, Steel/Steel)
And need I mention a small shot of NOS ? (88's only, unless you're brave)
Porting your heads can do alot, as well as a new camshaft. Don't polish the ports, cause the slight turbulence can help mix the air/fuel together a bit better.
If you want to stick with 4 bangers, and get an even lighter weight setup, you could go with Ecotecs, like me, but there's no kit, and you'd kinda loose the stock look.
I say do the duke if you have the cash.
------------------ Airman Michael C Casaceli Patrol Squadron Ten, United States Navy 1988 Pontiac Fiero 2.5L, soon to be 2.2L Ecotec Turbo (project starts in MARCH 2004) 1988 Oldsmobile Firenza 2.0L non-turbo (R.I.P.my beloved J-body. KIA by a Ford) 1994 Chevy S-10 4.3....COMING THIS WEEK!!!
[This message has been edited by fieroturbo (edited 03-03-2004).]
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11:12 PM
Godson Member
Posts: 36 From: Raytown, MO, USA Registered: Feb 2004
ok so let me ask this question, Comp cams has a "Beehive" Valve spring, I know very little about it, mainly that it is the same as the LS1 design and that it can increase power due to the lighter parts (smaller retainer etc.),so therefore would these springs be able to be used on the Duke and if so lighter valvetrain(w/ aluminum roller rockers, roller cam, and lightwieght valves would allow quite a light valvetrain rather cheaply right?).
Now I have one simple question on the dukes crank, is that if it is basically the same architecture as the SBC, you would right out of the box be able to use SBC connecting rods, if so light weight aftermarket parts right there quite cheap, also lightweight pistons. If so then the 2.5l from the S-10's would be a great donor as they are said to have a stronger bottom end that the fieros, plus the con rods, etc., with this work, altough alot of doing but little machining would increase revs, reliability and streetability, with cheap parts correct????
------------------ Don't judge me for how I talk, judge me for who I am.
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11:27 PM
Mar 4th, 2004
numan Member
Posts: 166 From: Kentucky, USA Registered: May 2003
If anyone has any experience with any of the above parts, feel free to add the pros/cons of your experience with them also.
Throttle Body 84-86 HOLLEY BIG BORE THROTTLE BODY W/ SENSORS
I purchased this item in June of 2003 I don’t see any better performance with it. Maybe just a bit at the higher end. It is sure is not worth the 300.00. However it does come with all new sensors and that is a plus. It is easy to install and does look nice when you install it. But the bottom line is there is little performance different. I would suggest you save your money and buy something else. For that type of money it is disappointing.
Just my 2 cents worth.
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03:05 AM
PFF
System Bot
bonzo Member
Posts: 1350 From: Jacksonville, FL, USA Registered: Jul 2003
How about a Super Duty 4 head. That should flow a lot better than stock and also flow better than a ported stock head. Bigger intake and exhaust valves! Frank
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01:25 PM
FastIndyFiero Member
Posts: 2546 From: Wichita, KS Registered: Aug 2002
I just got the flow numbers for my SD head from the machine shop. This head's ports were NOT expanded. This was only a Stage 1 job, which means that this thing could flow like crazy.
It finally stopped flowing at .700 inches valve lift. At .600" it was at 270 cfm. At .500", 250.4 CFM.
How about a Super Duty 4 head. That should flow a lot better than stock and also flow better than a ported stock head. Bigger intake and exhaust valves! Frank
That would be GREAT, and I'd be willing to sacrifice the stock look for one, but where do you GET one? On Kansas Racing Products site
They don't list any SD heads for sale, though they do have a SD block, at a whopping $2500 (probably a fair price, but still relatively expensive). How WOULD it fit? On the Indy's they have that huge (awesome looking) valve cover.
quote
Originally posted by fieroturbo:
MSD's Adjustable Ignition (add's what feels like a small shot of NOS)
Denso Iridium Spark Plugs. Reduces the chance of detonation, and runs the motor cooler.
Greddy E-manage ECM piggyback module, or the unit that West Coast Fiero's has (which may be easier to install, but not as effective).
Del West Titanium Valves and Retainers, with bronze valve guides. It's weird, but bronze and titanum have the least amount of friction than any other metal combination (i.e. Steel/Aluminum, Steel/Bronze, Steel/Steel)
Any links/Part Numbers/Prices on these? They sound interesting.
I just got the flow numbers for my SD head from the machine shop. This head's ports were NOT expanded. This was only a Stage 1 job, which means that this thing could flow like crazy.
It finally stopped flowing at .700 inches valve lift. At .600" it was at 270 cfm. At .500", 250.4 CFM.
SD heads just flow better!
FastIndyFiero
So how does that compare to a stock head. Also what size valves are in your head. I belive that it can accept an intake valve of 1.94 to 2.02 inchec and exhaust of 1.6 or 1.62 inches. The staock valve size is intake 1.75, exhaust 1.5 inches.
Frank P.S. I got a head comming that I just bought. Will put it on my '86 with Holley intake and TBI. Plus MSD6A, MSD coil and K&N filter. I will be using full roller crockers in this beast. Maybe I'll even get 100 HP out of it LOL LOL LOL
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06:44 PM
FastIndyFiero Member
Posts: 2546 From: Wichita, KS Registered: Aug 2002
Damn Good Argument on this thread. Its hard to show your intelligence level on the internet but you have done one great job in this thread!!! No sarcasm!!
+ for you
------------------ Failing to prepare - Is preparing to fail....
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02:01 AM
fst4rsc Member
Posts: 98 From: Farmington, NM Registered: Oct 2003
I got the hooker super comp headers from JEGS. You would have to call them for price and availability. Not enough people buy them to list on any web site. I think they were in the $500 range ceramic coated. They were expensive but well built. For the roller rockers, you also have to special order from JEGS to get the set of 8. They are the same as V 8 rockers which would have the set of 16. I think they were like $200 with the new studs. Amotion has cams and they could probably build one for probably any engine. My cam was about $200. So, all in all, the goodies were about a grand. I rebuilt the entire rear end power train (engine/transmission) for a total of about 2 grand. Of course, all this was 4 years ogo.
The one thing that worries me about the MSD system is this:
But I don't think it should be a problem?
fst4rsc, the Super Comp headers: That includes an intake and exhaust manifold?
quote
Originally posted by fotofrank: I got a head comming that I just bought. Will put it on my '86 with Holley intake and TBI. Plus MSD6A, MSD coil and K&N filter. I will be using full roller crockers in this beast.
Any info on this Holley Intake and MSD Coil? Part numbers or prices, or where to buy, if possible?
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11:38 PM
Mar 6th, 2004
Fierobsessed Member
Posts: 4782 From: Las Vegas, NV Registered: Dec 2001
Just so you know. The Mercruiser is a difficult swap, never been done before. It would need a SBC adaptor kit, the engine is not cross-flow, meaning that the intake and exhaust are on the same side of the head. The water pump situation is another big problem since mercruiser's and some RWD 2.5's do not have provisions on the side of the block for a waterpump. I think it would make much more sense to adapt the crank to a good strong S10 block. I really dont think the machining for the crank is that hard, The hardest part is drilling and tapping the six bolt holes for the flywheel. Anyone with a good accurate lathe can cut down the output of the crank to identical to the normal Iron duke size.
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01:38 PM
FastIndyFiero Member
Posts: 2546 From: Wichita, KS Registered: Aug 2002
Would there happen to be a strong, stock stroke crank that can take some abuse? There was a thread that Lloyd was talking about better crankshafts, but I can't remember what that thread was. I know about the '88 crank. Is there a stock stroke Mercruiser crank? My memory is failing me today...
There is no worry with the MSD ignition. The "tach output" on the MSD box is not used with our cars. I have installed an MSD 6A and MSD 6AL---no problemo with the stock tach. Frank
Guaranteed Performance Boost Cost = Free or at least cheap on many cars.
Make sure the engine is reaching WOT when you mash the pedal.
Fiero's long pedal cable streaches like hell. Many if not all Fiero have this problem and even NEW cables often won't solve it. If the engine can't reach WOT then you can't make full power no matter what you do to the engine.
Automatics suffer this problem worse than stick but all suffer it. The TV cable on the automatic adds considerable load to the pedal cable.
------------------ Edison Carter: When did the News become Entertainment? Murray: Since it was invented.
i could be way off, but i have always been under the impression that many SBC heads will bolt right on to the duke block, meaning you could snag a high flow SBC aluminum head, add the valves you want, and bolt it right up.
I believe i was told by kansas racing that they can supply you with different intakes to accomidate SBC heads used on a 4cyl.
something else you might want to consider if you are wanting to keep the duke. some members have been able to safely achieve 195-200 hp from a duke N/A by using the 86 S10 pickup duke block. with bigger bore, larger crank and rods, ported head, cam, etc.
These S10 blocks were built with a far superier bottum end to deal with the added weight and hauling requirements of a truck, hense the block can support more HP than the fiero duke.
The only mod required if i recall is simply tapping the other side of the block for a starter, as it is on the opposite side.
so in the end, you would by all apperances retain the stock 2.5 "look" but be hiding a respectably bigger amount of HP.
also, adding a turbo the the fiero duke has been proven a good way to end your dukes life early. i am willing to wager that the S10 duke would be more able to withstand a turbo than the fiero duke. turbo'ing a stock s10 duke would be more cost effective than building one up with beefy internals.
I got the hooker super comp headers from JEGS. You would have to call them for price and availability. Not enough people buy them to list on any web site. I think they were in the $500 range ceramic coated. They were expensive but well built. For the roller rockers, you also have to special order from JEGS to get the set of 8. They are the same as V 8 rockers which would have the set of 16. I think they were like $200 with the new studs. Amotion has cams and they could probably build one for probably any engine. My cam was about $200. So, all in all, the goodies were about a grand. I rebuilt the entire rear end power train (engine/transmission) for a total of about 2 grand. Of course, all this was 4 years ogo.
I checked out your website, very nice write-up. I'll study it later, as I'm about to undertake my own build. What caught my attention on yours was the header. I have a Super-Comp header I bought off eBay (new), and it's different than yours. Mine exits under the engine, so it won't have the loop where the factory cat sits. I think I figured out how I can use this, but I wonder if anyone else has already used one of these. Also, what are y'all using for cradle bushings and engine mounts? I already have poly all over the front suspension, and will be doing poly in the rear as part of the engine project. BTW, Eric, nice looking engine. You did a great job on the detail, colors, etc.
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01:51 PM
FastIndyFiero Member
Posts: 2546 From: Wichita, KS Registered: Aug 2002
i could be way off, but i have always been under the impression that many SBC heads will bolt right on to the duke block, meaning you could snag a high flow SBC aluminum head, add the valves you want, and bolt it right up.
Umm...yeah, you're mostly off.
The Super Duty block manufactured by KRP can be machined by them to accept SBC heads. But as far as production blocks, it's a no-go. There isn't enough material in the right places, etc...
Would doing all this to your exhaust require to to get a new ECM? I hear the oxygen sensor is no longer useful on a modified exhaust... but i dunno much.
No, the 2.5 head is the only that can fit without machining the block differently. There are two different patterns, though. One, (the Fiero, FWD pattern) has the bolt closest to the water pump moved a little off-board of the line of bolts on the firwall side. The other (rear-wheel drive) pattern has this hole in line with the others.
? (88's only, unless you're brave)
