I have my bone stock 88 2.5. Found a pro-engine builder that I'm making a deal with to rebuild it He does a lot of custom one-off engines from a twin turbo rat rod to a n/a bigblock that dynoed at 800+Hp. After reinforcing and then boring the block, he said he would like to lighten up the internals and do a full balance of everything. Custom intake and exhaust with a one off Tbi system. I trust what ever he feels will wake up the ol' duke after seeing some of the other projects he's working on. My only request is that I dont almost die trying to merge onto a fast moving highway and that it's dependable. I like the stock isuzu 5 speed as the gears are evenly spaced. Does anyone know of some higher quality shift forks? I'd like to clean it up a bit. I dont try to shift hard, but 3rd gear dose grind a bit when shifting into it. Thoughts?
1988 Fiero 2.5
[This message has been edited by Zeak (edited 02-19-2014).]
If your builder is talking about lightening up the internals he has never looked inside the Iron Duke before.
Iron Duke Crank:
Iron Duke Rods:
Unless you just like to spend money for the sake of spending it, leave it alone.
This kind of thread comes up at least a couple of times every year, and the people that have seen the results of every one of these builds balks. Then the original poster of the thread gets indignant and accuses the naysayers of being closed minded... then the thread dies with either a completely expected failure/roadblock or a change of direction for the build moving onto another engine before the Duke is finished.
I'm not trying to be an ass... I've just seen this same conversation soooooo many times. There just isn't enough metal in an Iron Duke to work with.
I can agree with the part about the duke builds normally going to crap. I'm not defending the duke as the underdog either. I know the engine sucks. This is all from just the first conversation last night. There was also talk of a v6 or newer in-line 4. The duke seemed to be the most exciting. This is why I ask you guys first. As for doing a swap of say, an eco-tec. Why does everyone try to replace the stock fuel management system? Why not just use the harness and Ecm that came from the donor car? It seemed like a lot of extra hassle. I'm not a fan of v6 or v8's in the fiero as It's more power and torque than I would ever have need for.
I asked about the shift forks because there known to be a weak point in the isuzu trans. 3rd gear is more than likely a synchro or something I think. Thanks for the replys and please keep them coming.
If you want to go with a 2.2 Ecotec... give Roger Thelin a call. Thelin Sells
There is more support for the Ecotech's stock electronics now than there was back when a lot of the original Ecotec build threads on this forum got started.
However, there is no known adapter plate to go from the Ecotec bellhousing to the Metric pattern used on the Isuzu trans. I would use the F23 that came with a manual Ecotec in that case. Roger lists all the hardware needed for the swap on his site. I have his rear trans mount in my 88 GT for my F23 swap and it is a quality piece. He did his engineering on an 88 chassis...
If budget isnt really a constraint, then do a Super Duty version with the right kind of block and matching parts. it should still bolt up to the cradle with minimal mods if I'm not mistaken. IMO that is the RIGHT way to go to make some power and still keeping it a Pontiac.
If it's gotta be a 4 cyl, Anything BUT the duke (for performance). I've got a rebuilt duke in my 85, (most reliable car I've ever owned), go figure ! I was going to 3800 it, but decided it's" too good a car" and decided to put the 3800 in another car. If you're going 4 cyl with no budget, at least use a Dual OHC, they are capable of some Real power, and can be as reliable as anything else.
88 uses balancer to drive oil pump etc. Balancer problems have wreck many engines. Your "expert" needs address balancer problems. Weak bearings for a start.
If your bent on "improving" DIS Duke, get 87 block w/o balancer.
GM built Dukes as cheap and light as possible, mainly for commuter cars like Monza Fiero etc. Why? GM used Aluminum 2300 engine for Vega. Vega w/ Al engine w/ Overhead cam is good on paper but many didn't last... 30,000 to 50,000mile and eats oil etc. Al engine is a big reason why Vega = Junk. To "fix" that problem... GM introduced the Iron Duke in 1977.
Originally posted by Lou6t4gto: If it's gotta be a 4 cyl, Anything BUT the duke (for performance).
I tend to agree. If you have a healthy budget and want something rare and uber-cool, look for a Super Duty 4-cyl. Your engine builder will have lots of fun with that (in a good way). And then after he's done with it, you'll have lots of fun with it too.
Aside from that, there are many choices available, all of which will yield more performance with more reliability than the Duke... like the Quad 4, 2.2 OHV, and EcoTec, to name a few.
There was also talk of a v6 or newer in-line 4. The duke seemed to be the most exciting.
I've daily driven and autocrossed a 5-spd duke for the last four years (and have quite enjoyed it), but I have no idea how anyone could ever describe the duke as "the most exciting". The most exciting what? Makes no sense to me at all.
I'm now daily driving a 5-spd Formula. I can't wait to autocross it in the spring. The 2.8 isn't exactly the most potent engine, but compared to the duke it's a powerhouse.
Unless you're desiring to be some kind of martyr, forget about spending any money trying to hotrod the duke. You'd be looking at minimal gain from maximal expense.
I think the most important thing for you to think about is this -
You want the Duke to have more power and you want it to be dependable - you can't have both. As said above, the Duke was designed to be a commuter motor. When you start to poor money into it, you can increase the power but you will shorten it's life. They are just not a motor to be "built" for power. If you want more get up and go - but want good reliability, have your engine guy build you a near stock 3.4 V6 - plenty of fun get up and go, very reliable if built with quality parts. Dump the Izusu and get stock Getrag or an F23.
I've built and driven a few Fiero's - 4.9 Caddy V8, 3800 SC, 350SBC, 3.4. I have also owned a Duke car and an all stock 88 Formula. Each were fun in their own way - the swapped cars were great but required some tinkering. By far, my most favorite Fiero to drive was the all stock 88 Formula. The only change I would ever make to that would be to build a nice 3.4 for a little more "seat of the pants" fun.
My .02 cents - If you are dead set on an inline 4 - rebuild the Duke to stock specs using the best quality parts you can find - don't waste your money on "hot rodding" it - you will end up doing another rebuild or swap down the road or worse, loose interest! Good luck which ever way you decide.
The easiest cheapest way to get more power is to swap in a 2.8 from a V6 car - all the stuff is readily available, and the stock V6 will give you more power (and far more reliability) than the most aggressive 4 cylinder modifications.
Originally posted by Zeak: I can agree with the part about the duke builds normally going to crap. I'm not defending the duke as the underdog either. I know the engine sucks. This is all from just the first conversation last night. There was also talk of a v6 or newer in-line 4. The duke seemed to be the most exciting.
Originally posted by Patrick: I've daily driven and autocrossed a 5-spd duke for the last four years (and have quite enjoyed it), but I have no idea how anyone could ever describe the duke as "the most exciting".
I've heard the Duke being referred to by many different phrases --- several of which aren't suitable for a "family-oriented-forum" similar to this one --- but to refer to it as "the most exciting" (to use your terminology, Zeak) ---- never has been one of those phrases. Might you be inadvertently mistaking the 4-cylinder Fiero engine with a different 4-cylinder engine?
Originally posted by Zeak: As for doing a swap of say, an eco-tec. Why does everyone try to replace the stock fuel management system? Why not just use the harness and Ecm that came from the donor car? It seemed like a lot of extra hassle.
I'm not sure what research gave you this idea. Maybe your engine builder? 98% of Fiero swaps keep the fuel management system that was original to the engine they're swapping in. Most every swap here utilizes the donor car's harness and ECU. But that doesn't mean you just plug it in, the Fiero chassis has two connecting points where the chassis interacts with the engine, each with around 15-20 wiring connections. Fuses, diagnostics, A/C, starter commands, reverse lights, vehicle speed, gauge feeds, power feeds, relay bypasses, etc.
This whole thread could have been avoided via some searching. Once a week someone brings up the 200hp Duke dream.