I'm curious, I know it's been done, and I've seen pictures of the crankshaft differences but I can't find anywhere/anyone to buy from. also, if a 2.5L was stroked .40 over what size would it make it? I've been thinking I love my little Duke in my 88 a lot, and don't really want to do an engine swap so what about stroking it and pushing the 2.5 to a 3.0L and upgrading the valve train with a decent cam, roller rockers, better valve springs, and getting it ported.
I know I can't be the first to think of this, so if you have any thoughs, info, etc. I'd be curioous to see where it goes.
------------------ 1987 Fiero Auto Base Coupe 56k Original Miles 1988 FIERO Coupe "IRON DUKE" 5-Speed (the show car ;-) 1992 Firebird T-Tops V-8 24k original Florida miles(collectors car)
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10:24 PM
PFF
System Bot
DPWood Member
Posts: 540 From: Aylmer, Ont. Canada Registered: May 2002
Ummm... Not sure where you're getting a .400 stroke from. Are you thinking of having it bored as well as stroked?? More common is .030 over. Cylinder will usually clean up with that. It would only give about 2.5CC increase in displacement so it wouldn't make much impact on the total amount in Litres.
IIRC A marine stroker crank for the Duke as a 3.6 inch throw. You use 5.7 inch rods and the marine D dish top pistons. I think cam available for the Mercruiser 4 banger output 120 HP (at least that was what was printed on the valve cover) Downside is that it is a flat tappet cam not a roller. You almost would have to get a custom grind to really pull power out of a stroked Duke. The fiero store lists a performance roller cam but I doubt it would ideal for a 3.0L. They don't list the specs or dyno figures for it.
------------------ His Fiero: 1984 2M4 Coupe
Her Fiero: 1984 2M4 Convertible
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11:05 PM
Jul 20th, 2009
gtxbullet Member
Posts: 4180 From: Pewaukee, Wisconsin, USA Registered: Apr 2008
sorry I meant a .040 over Bore...lol also what is the Marine version?? or is that just the name of the kit? I looked at Comp Cams and there are 3 different aftermarket cams, and the HP numbers are Grind number: 240H - about 10-15 HP 252H - about 15-20 HP 260H - about 20-24 HP these are estimates because no one has posted any dyno numbers relating to a Fiero I4. I'm half tempted just to buy one and see if it's noticeably differnt. worst case is I spent $300 for what a good Exhaust system would cost. and I do my own exhausts so I'm saving money there already.
any Price numbers or places to buy the stroke kit?
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12:55 AM
joshh44 Member
Posts: 2166 From: Nanaimo, B.C, Canada Registered: Aug 2007
also apparently the cly heads are pretty weak and pro to cracking. im only going off of what other people are saying. you can swap out the cly head with a chevy s10 head. i believe they have better flowing cly heads? and maybe stronger to?
iv thought about beefing up the duke and put some extra mods on it. then i got into reading into engine swaps and doing the 3.8 swap would cost just as much as adding perfomence parts on the duke and having double if not triple the hp with afew add on parts to the 3.8 and still have great MPG like the dukes.
but i think it would be pretty rad to have a pretty decent 2.5 fiero that can keep up, if not out perform a 2.8 fiero.
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02:35 AM
White Spyder Member
Posts: 1047 From: Gluckstadt USA Registered: Sep 2007
Mercury Marine uses a version of the Duke. They come in 2.5/120 HP and 3.0/140 HP. The head design is a little bit differant, intake and exhaust on the same side, and it uses a mechanical fuel pump. These engines are designed to run at wide-open throtle/3000+ RPM all day long. I always wondered what they would do in a Fiero. Considering you live in the land of many lakes, you should be able to find one without much trouble.
Bob
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07:56 AM
Gwain Member
Posts: 460 From: Titusville, Florida, USA Registered: Dec 2004
He ran a 2.8 stroker in our car club here in Florida. He ran quite a few different mods over it's life time, but ended up pulling the engine this year when the block failed.
The 2.8's don't have much "meat" for over boring and such.
Make sure it is DIS! Most crank shaft are not have DIS Timing Notch Wheel. Stroked are usually HEI in this engine. (84-86 Duke) There no notch wheel.
But wait... 88 even worst. Balancer/oil pump would need gear on crank shaft. No stroker likely have that. 87 don't have that problem. see cave, powertrain, engine, 4 cyl, quick ref
Most shop won't .040 cyl. .010-.020 max. Cyl get do weak. Cyl bore to cyl bore in main problem.
Plus... Make sure you are making all power it can. see cave, powertrain, engine, general, throttle cable
------------------ Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should. (Jurassic Park)
I understand the desire to make the stock motor better. I've been doing that with my GT. That said, the stock 2.8 is pretty tough and has been raced alot both in boats and offroad. It is a decent candidate for modest hotrodding, maybe up to 200 hp. Past that there are some pretty critical needs such as conrods etc.
The Duke however, was built as an economy engine. Upgrading it much more than 20 will stress those light parts.
If you are talking an upgrade cam and porting go for it. But to get into the expense and difficulties of creating a stroker version, you will have an interesting project with uncertain outcome IMHO.
If you turbo'd it for instance, you'd find it would at some point have a catastrophic failure if you were trying for 150 - 200 hp range.
You might want to consider the Quad 4 maybe, or another 4 cylinder that would be close to the stock in looks and weight.
Just my .02
Arn
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09:38 AM
TopNotch Member
Posts: 3537 From: Lawrenceville, GA USA Registered: Feb 2009
Start with a 91 or 92 VIN R duke. It's already rated at 110 HP out of the box. It wouldn't take must to get 120 or 130 out of one of those. I don't think you would have to stroke or bore it -- just put in a slightly more aggressive cam and ported intake and output.
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11:12 AM
gtxbullet Member
Posts: 4180 From: Pewaukee, Wisconsin, USA Registered: Apr 2008
I think I'll look into the S10 version considering it's basically a drop in set up. also I have a DIS (Coil Pack with Ignition Module), not HEI (Distributor).
just for kicks and giggles, what about a Carbed set up? I've seen a 2.5 Iron Duke in a 20's Roadster and he had an aluminum Edelbrock Intake with a Carb on it. he got it from an 80's car.
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11:28 AM
PFF
System Bot
fierosound Member
Posts: 15220 From: Calgary, Canada Registered: Nov 1999
Billet cranks are also available from Scat in a variety of strokes. I've got a 3.100".
------------------ My Web page | The Turbo Super Duty Build. You know that little voice that says it can't be done? I duct-taped its mouth shut and pushed it down a flight of stairs. (Leader of the Insurgency)
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10:23 AM
gtxbullet Member
Posts: 4180 From: Pewaukee, Wisconsin, USA Registered: Apr 2008
Billet cranks are also available from Scat in a variety of strokes. I've got a 3.100".
I just got done reading through your whole post. WOW!!!! that will be a grreat little monster when you're done. but as far as the head with..."balls", the superduty with red valve cover. I saw that thing on ebay for $2500. did you buy it? also I'm curious about the 4-injector style intake and the aluminum aftermarket one that was posted in your first pictures.
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10:46 AM
fierosound Member
Posts: 15220 From: Calgary, Canada Registered: Nov 1999
Aluminum intake on eBay $100 [URL=http://cgi.ebay.com/ebaymotors/PONTIAC-SUPER-DUTY-ALUMINUM-INTAKE-4-CYLINDER-2-5-liter_W0QQcmdZViewItemQQ_trkparmsZ65Q3a12Q7c66Q3a2Q7c39Q3a1Q7c72Q3a1205Q7c293Q3a1Q7c294Q3a50QQ_trksidZp3286Q2ec0Q2em14QQhashZitem19b52d1ba2QQitemZ110413814690QQptZMotorsQ 5fCar]http://cgi.ebay.com/ebaymot...690QQptZMotorsQ5fCar[/URL] Q5fTruckQ5fPartsQ5fAccessories
Head gasket [URL=http://cgi.ebay.com/ebaymotors/Fel-Pro-Performance-1015-Pontiac-Super-Duty-4-cyl-gskt_W0QQcmdZViewItemQQ_trkparmsZ65Q3a12Q7c66Q3a2Q7c39Q3a1Q7c72Q3a1205Q7c293Q3a1Q7c294Q3a50QQ_trksidZp3286Q2ec0Q2em14QQhashZitem3ef4dbb5c6QQitemZ270396011974QQptZMotorsQ5 fCarQ]http://cgi.ebay.com/ebaymot...74QQptZMotorsQ5fCarQ[/URL] 5fTruckQ5fPartsQ5fAccessories
can I run that on a regular Duke, or do I need the superduty? as for the headgasket that's even big bore than the Merc motor, and those have a 4" bore.
