Are these bidders Fiero people or dirt-track racers?

http://cgi.ebay.com/ebaymot...QQrdZ1QQcmdZViewItem

quote Originally posted by KurtAKX: Are these bidders Fiero people or dirt-track racers? http://cgi.ebay.com/ebaymot...QQrdZ1QQcmdZViewItem

None are me that's for sure. Pretty trick. If you have the cash go for it. Only problems are possibly fitting airfilters. And the way you tune them is to put a special device over the openings which you won't be able to do because of the trunk. I am sure you can tune them without this device but that is the best way to get them insync.

quote Originally posted by The_Stickman2: Or there is always this. http://cgi.ebay.com/ebaymot...dZ1QQsspagenameZWDVW

That's what I was JUST on ebay looking for!
I never see the good stuff because I only search the common terms like "GM 151", "Pontiac 2.5", "2.5 151", and not "Super duty" or "Superduty" because I get sick of only getting results related to early 60's Pontiac V8s and Diesel Ford Pickups.

Oh and I wouldn't touch the carb setup myself, because I want this to be something that:
A) can be replicated by anyone
B) makes consistent power. I understand that in a thesaurus, Weber is listed as an antonym to consistent.

[This message has been edited by KurtAKX (edited 03-21-2008).]

Any updates on this?

Something I wondered the last time I read a "big bad duke"-type thread but never got around to asking: could you use an SBC throttle body in place of the duke throttle-body? would it make a difference?

[This message has been edited by PerKr (edited 11-01-2008).]

bump?

Still gathering the last few parts:
https://www.fiero.nl/forum/Forum2/HTML/098791.html
https://www.fiero.nl/forum/Forum1/HTML/074825.html

[This message has been edited by KurtAKX (edited 03-11-2009).]

https://www.fiero.nl/forum/Forum2/HTML/023474.html

not that my engine has documented results, or the capability for "anyone" to perform this build, but it did run pretty well before the fuel line broke. might be useful to answer some questions, or provide another avenue for parts. i hope your final outcome is better than mine was. i am back in the game again. just picked up an 87 dis 5 speed car to tinker with. had to promise the wife that i wouldn't make it a money pit like the last one, so it will be way milder. but, i am back in the game...yay!!!

Update:

My flow bench is almost done. Here's a couple teaser pics of the progress:

First I made a plate from a piece of cheap melamine that had bolt holes and bore centers in the correct places.

While I suppose this is possible using a set of transfer punches and a good guess at the location of the bores, I sketched out the bolt and bore layout from a Super Duty head machining print.
Also, since I'm using PVC inserts to seal against the bottom of the head, I had to cut the holes bigger than 4".

Schedule 40 PVC has a nice 4" ID that is a good approximation of the 2.5 bore, but the OD is about 4.52" Since the bore centers are only 4.40" inches on a Duke, this meant that the holes in my plate overlapped.

The next problem the bore center vs PVC thickness issue was related to making the PVC fit so close together. To do this, I had to machine about .050" off the OD of the pipe in two diametrically opposed places down the full length of the pipe- about 6 inches. Here's a crappy pic attempting to demonstrate that the pipe had "flats" down the sides when I was done.


After getting the pipes to fit, I simply turned the whole thing upside down, put 2mm spacers around the perimeter of the melamine, and pushed the tubes through and epoxied them. The 2mm spacers ensure that the PVC pipes protrude from the head mounting face more so when I put the head on, clamp force is concentrated around the bores. Heres some pics of the nearly-final product:




And a shot from underneath:


Still on the to-do list:
-make some plugs that lock into the bottom of the tubes and allow me to pull vacuum (or generate pressure to work exhaust ports)
-peel the butcher paper off where the epoxy leaked through
-cut a gasket for bench out of the thin 30x45cm piece of foam I bought at Meijer.

If I get ambitious, I'll show you what I'm doing to actuate the valves on the bench and how to calibrate a MAF sensor for this using a set of standard-diameter circular orifices made of thin plate and a tube of water.

[This message has been edited by KurtAKX (edited 04-09-2009).]

I'm going to bump this. It seems to be the most recent thread I can find on building up a duke the way it should be built. If there is were another official thread for this build that doesnt start with "dyno results" it would be easier to find for anyone looking into building up their duke (I don't know if there is and I couldn't find one - just want to point that out).

Now as a technician who worked in a shop for a few years, until I got this Fiero, I was mainly a muscle car enthusiast. I listened, read, found out anything I could about engines, even built one, a ford 351w with a few above stock modifications(300+ horsepower). This went into my 68 mustang I had at the time.

In this school of thought I learned that for a street machine, or mostly street including some quarter mile type drag racing, the main thing you are looking for is low end torque. This is what gets you off the line faster (or at the stop light faster), and also happens to be one of the main good points of the duke engine. So, with heads, we are talking, port matching, possibly bowl porting probably the best way to go. Stock heads have a grain in them that creates turbulence which actually improves air flow and fuel atomization, unless you have a motor that will be making really high rpms like an indy or stock car where the air is just being rammed in through a long intake passage, then you want the full port and polish.

Using 87-later crank and rods is good, although simply having the crank and stuff balanced may be enough to make the crank reliable enough for up to 5 grand rpms consistently. I had my 351w balanced and after it was done machine shop guy said it was good thing I did If I remember correctly one of the counterweights was off by like 10g or something.

This site has a formula for getting 120-130 horsepower out of a duke engine fiero:
http://ironduke7.tripod.com/builtduke.htm

Another concern. I live in a state where I am required to pass emissions tests every year, so this build must pass emissions. Mainly this concerns what cam to use.

A lot of people are writing off the duke, and some even the fiero with it. I believe we can safely and reliably create a build that gets 120-140 hp or even 150 hp, doesn't cost too much(hopefully comparable to or less than buying new or rebuilt), and still gets great gas mileage (its fun telling people I drive an 86 pontiac that gets 40 mpg and watching their reaction). If we can have a build that uses relatively cheaper parts like from summit racing or something, that would be great, too.

I plan on building this on the side over the next year or 2 sometime, then putting it in when ready.

Either way, I am having a lot of fun driving the duke, and dont plan on exchanging it for a V6 that breaks more often and uses more gas and won't last nearly as long. I have 130,000 or so on odometer and given the oil burning, I think its the original engine and it sounds like it will keep going and going.

The 84-86 duke never exceeded 70% VE. There's plenty of room for improvement.

quote Originally posted by KurtAKX: The 84-86 duke never exceeded 70% VE. There's plenty of room for improvement.

what sort of modifications do you have in mind?

Question on the S-10 block. I thought I read some were on this forum that the S-10 2.5 engine runs in the opposite direction of the Fiero 2.5? Which would entail getting a different water pump, and maybe alt. Oh would the ECM need to be changed? Lets see the crank sensor and coils and module should be ok. I also question the block having the correct bosses cast into it for the engine mounts. Any one familiar with this? Is this the case?


Thanks,
Steve W.
NE Grand Rapids, MI
88 Coupe

quote Originally posted by solotwo: Question on the S-10 block. I thought I read some were on this forum that the S-10 2.5 engine runs in the opposite direction of the Fiero 2.5? Which would entail getting a different water pump, and maybe alt. Oh would the ECM need to be changed? Lets see the crank sensor and coils and module should be ok. I also question the block having the correct bosses cast into it for the engine mounts. Any one familiar with this? Is this the case? Thanks, Steve W. NE Grand Rapids, MI 88 Coupe

If the engine ran the other direction, you would have bigger problems then the alternator and water pump.