quote Originally posted by Avery Montembeault: THANK YOU for being another person who took on the challenge of building up a duke despite the heavy "Want horsepower, drop in a v8, its the ONLY way" mentality.

Yea, there is a lot of that attitude going on around here. Perhaps some people are just afraid of change.

------------------
Fiero-related Conversions Performed:

1985 SE 3800 Series 1 SC 4T60-E
1987 Coupe 3800 Series II 4T60-E
1987 SE 3.4 TDC 5-speed
1984 Coupe SBC V8 non-OD to 4T60 OD swap

http://dtcc.cz28.com

H+M Performance sells remanufactured 3.0 cranks for $178. Not sure what the core is though. They also list a #499311 crank for $60 which is reported to be good for 7600 RPM. The 311 is 3" stroke the 3.0 is 3.6".

I have figured out a way to do all my parts for my build up cheap, with the exception of the head. I am trying to find out which factory casting flows the best, I do not want to do major surgery to get good numbers and the stock flow is weak for what I want to do. Any ideas or leads?

Erik-

quote Originally posted by erikred: I have figured out a way to do all my parts for my build up cheap, with the exception of the head. I am trying to find out which factory casting flows the best, I do not want to do major surgery to get good numbers and the stock flow is weak for what I want to do. Any ideas or leads? Erik-

been told that cast. #552 cyl head flows best.

This question has probably already been asked, but, is there a bearing cap girdle for the Duke that would strengthen the lower block of an otherwise stock engine?

Would this help or is the crank itself the problem?

Is there a stronger crank which will work with the stock pistons and rods?

I am looking at the (remote) possibility that I would build a reliable Duke in the 120 to 150hp range so I am now gathering as much new information as I can. My website contains all of the information I have gathered so far so take a look and let me know what I have missed.

BTW sounds like an awesome engine project, been a great read.

Ira

------------------
Ira Crummey
1984 econo coupe (soon to depart)
1985 coupe (work in progress)
The Iron Duke Resource Site

[This message has been edited by Monza76 (edited 03-08-2003).]

quote Originally posted by mrossum: been told that cast. #552 cyl head flows best.

That's what I've heard too. I have one now that I'm using for my "performance" build up.

Pat

------------------

84SE w/ T-Tops

I just had a good laugh, I just found out that a mercruiser 3.0 Wont fit into a Fiero, unless you get an Archie kit. It's an Iron duke with A SBC bolt pattern. Its also missing the side water inlet that you would need for a Fiero. So much for that idea. However, I may purchase a 3.0 crank very soon, it shows promise.

------------------

"How do I get one of those Smileys that rolls back and forth accross the screen?" -Archie

MAN I LOVE THIS CAR. still don't have power numbers, but will get them soon.......

Any new news on this car, the weather is warm and I figure it should be out tearing up the streets!

Ya I would love to see some pic's! I hate to say it but the v8 guys do show alot of pictures...

------------------

I checked with H&M Performance about availability, price and core deposit on the Mercruiser crank. The crank cost $178.00 and has a $60.00 core charge, for a total of $238.00. Here is the problem, and I am not sure which crank to get. One stock number has two piece bearings and the has one piece bearings. Which one would you use? I think I have heard of one piece bearings, butI am not sure how they work or what they look like. Anybody got any ideas?
Jim

------------------
87 Gold GT down for upgrades
86 Red coupe ana duke 5 speed running now daily driver
84 IRM Turbo Duke, Loaded with goodies
84 Silver SE Parts

quote Originally posted by fix her up: I checked with H&M Performance about availability, price and core deposit on the Mercruiser crank. The crank cost $178.00 and has a $60.00 core charge, for a total of $238.00. Here is the problem, and I am not sure which crank to get. One stock number has two piece bearings and the has one piece bearings. Which one would you use? I think I have heard of one piece bearings, butI am not sure how they work or what they look like. Anybody got any ideas? Jim

maybe they are talking about 1 or 2 piece rear main seal. if so, i would use 1 piece seal. they leak less. if they are really talking about 1 piece bearings, i would like to know how they get them on the crank??? just my 2 cents worth..........charley j

------------------
86 econo coupe-ground stompin' stroker 4 cyl, 88 rear cradle, koni's with coil overs, lowered 3 inches, mr2 spoiler on decklid. e-mail ossum1@hotmail.com

Would love to here how the duke is doing. Thank you for doing what a lot of us duke owners want to do! Keep up the good work.

How about a recap of the engine build, I know you have outlined everything here but this has become a very big thread, a condensed version would be very helpful to those of us who would like to try something similar (if not quite so ambitious). I would like a stronger Duke, but I am not pushing as far as you have. I don't mean to have you go over everything, just the high lights of what worked such as:

- what block?
- what crank?
- did crank or block require machine work?
- what connecting rods and pistons?
- what head or head modifications?
- what head gasket?
- what cam?
- what fuel system and modifications ?(injectors, etc.)
- any problem with flywheel or clutch?
- what oil pump?

You can fill in any gaps I may have missed.

I am so glad to see that there are still a few people out there who feel that a four cylinder Fiero is still a valid alternative. It seems that , too often, the engine swap guys put down anyone who suggests building a better Duke. Usually there responses mean well, the cost of doing a 2.5 right is very high, but often they forget the complexity and cost involved in a swap as well. I would like about 120hp, more would be better but I am realistic about what I can accomplish with my funds and abilities. The Duke is compact and logically laid out so that it is so much easier to work on then most of the alternatives as well.

Keep up the good work

Ira

quote Originally posted by Monza76:Has anyone actually used the Mercruiser 3.0L crank and can comment on what machine work was required and what pistons and rods to use for near stock compression ratio?

I dunno about yall, but if I am gonna go through the trouble of swapping in a different crank, it is not gonna end up with stock compression. I am thinking 13:1 ...unless its turboed

quote Originally posted by Monza76:What about the 2.5 used in the late 1970s RWD Sunbird...

'70s Sunbird? Can't recall ever seeing one of those. Could I get some more info from you, or anyone else.

------------------
--Jess--
AIM/YIM: asyferme

If you expect the unexpected, was it really even UNexpected in the first place?

'85 SE, 2.5, 5spd (350 standing by waiting for ole duke to puke)
'86 SE, 2.8, auto (pushrod 3.4 swap on hold)

'02 Yamaha R6, blue/white, 3600 miles, LIGHT case of roadrash, for sale. Will accept Fiero(s) and/or parts as PARTIAL trade.

Around 1976 Pontiac was given a version of the Chevy Monza with the 2.5L Iron Duke. The engine was a response to the Vega engine which had a habit of self destructing. The Sunbird name lasted until the model was dropped for the new FWD J2000 but after a couple of years they dusted off the name and stuck it on the FWD. I owned a Chevy Monza Towne coupe (their spelling) but I liked the style of the Pontiac.
The 2.5 in those cars did not have the crossflow head (carb and exhaust were on the same side) but the basic engine block was there, with a little mors internal structure (probably similar to the S10 engine). It did not make very much horsepower, typical of the late 70s, definitely less than 90, possibly less than 80 (remember 305 V8s from that era had only about 120hp, 350s ranged from 150 to 200).

this is the only pic I could find, a 1980 coupe.
Ira

So let me see if I have this right:

- stock block 1985
- Mercruiser crank (3.0L) (older type)
- Aftermarket rods and pistons (carefully figure out the correct numbers to end up with about 10:1 CR)
- Quality rebuild parts (bearings gaskets etc.)
- Improved cam, but nothing too radical.
- Machine head for BBC rocker studs and use roller rockers for BBC
- Mild port job on stock head (gasket match intake and exhaust, open up intake ports slightly remove some of the swirl vane material)
- Holley Throttle body with mildly modified stock intake.
- Stock electronics
- Free flowing exhaust

Did I miss anything?

What sort of power and reliability should this provide?

[This message has been edited by Monza76 (edited 05-25-2003).]

3.250 stroke crank from 63-70 nova 153. have to have an adapter from 1 piece to 2 piece rear main seal. had to machine about 3/4" off back of crank and drill a new flywhel bolt pattern in what was left. custom aluminum flywheel was then made to match the crank. crower 6" sportsman rods. .030" over silvolite hypereutectic pistons. nothing fancy about pistons. stock configuration for fiero worked well. if you want less conpression, you need custom pistons. arp studs for the main journals and the head. schneider racing custom ground cam. cam specs: lift-.493" int, .465" exh. duration-260 deg gross, 202 deg @ .050" lift. lobe seperation-110. kinda mild cause the car has to pass smog. good port and polish in cyl head. i used a 87-92 s-10 head with 642 casting number. all the race car machinests said this is the head that breathes the best. had to make a little adapter for the intake manifold to fit. stock size stainless valves. titanium keepers and locks. 454 screw in studs (7/16"). had to machine the head for these to fit. also had to have the guide plates laser cut. crower 1.8 stainless roller rockers for intake, and 1.7 for the exhaust. custom length crower hardened pushrods. 454 injector in my stock tbi unit. changed the stock header type manifold to a 180 degree cast iron manifold with a custom built 2 into 1 header pipe. 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 fuel pump.

------------------
86 econo coupe-ground stompin' stroker 4 cyl, 88 rear cradle, koni's with coil overs, lowered 3 inches, mr2 spoiler on decklid. e-mail ossum1@hotmail.com

[This message has been edited by mrossum (edited 06-06-2003).]

quote Originally posted by Monza76: So let me see if I have this right: - stock block 1985 - Mercruiser crank (3.0L) (older type) - Aftermarket rods and pistons (carefully figure out the correct numbers to end up with about 10:1 CR) - Quality rebuild parts (bearings gaskets etc.) - Improved cam, but nothing too radical. - Machine head for BBC rocker studs and use roller rockers for BBC - Mild port job on stock head (gasket match intake and exhaust, open up intake ports slightly remove some of the swirl vane material) - Holley Throttle body with mildly modified stock intake. - Stock electronics - Free flowing exhaust Did I miss anything? What sort of power and reliability should this provide? [This message has been edited by Monza76 (edited 05-25-2003).]

This combo looks good but I would make some "subtle" changes...

Use a modified intake to accept "other" throttle bodies, drill and weld in bosses to accept port injectors (aimed directly into the port), then flow bench it to slightly exceed max desired RPMs. To run it, use an after market ECM. Kudos on the thread. My opinion is that power can be made from any starting point and doesn't necessarily require the big $$. (Use the Porsche GT1 as a reference to avoid big $$/HP) So getting a 3X improvement from a stock engine is quite an accomplishement and you should get props for it. Technician did the same thing a while back and caught flack (as well as praise) for his efforts. Most importantly is that you enjoy yourself and have fun with it. G/L

P.S. O-ring the heads next time you take it down. That way when you add the NO2, you won't have any problems.

P.S. Anyone collecting stats on things such ... longest running thread?

[This message has been edited by 87GTZ34 (edited 06-06-2003).]

machine work on intake does not work. has a monster vacuum leak. am now gathering parts to put 87-8 intake and tbi on it. all ports line up, but fuel lines and throttle cable are different. will get it done shortly. already made adjustable fuel pressure regulator for 87 style t.b.i.

------------------
86 econo coupe-ground stompin' stroker 4 cyl, 88 rear cradle, koni's with coil overs, lowered 3 inches, mr2 spoiler on decklid. e-mail ossum1@hotmail.com

Did you try the port injection conversion? If so that's too bad that it didn't work out. I wouldn't give up on it yet, but I would do what you're doing to make the car driveable. What other TB did you try and what computer did you use? Thanks for the update and continued G/L!

quote Originally posted by Monza76: I am so glad to see that there are still a few people out there who feel that a four cylinder Fiero is still a valid alternative. Ira

Ira, What about Clifford Products, their slogan is 4/6=8

Here is their Link. http://cliffordperformanceshop.com/home.htm

------------------
86 "PoSE" Needs every thing but 4 NEW Tires!!! They ride better when new, not like after they sit for 3 years!
http://home.cfl.rr.com/fierose

[This message has been edited by Kento (edited 07-07-2003).]

quote Originally posted by 87GTZ34: Did you try the port injection conversion? If so that's too bad that it didn't work out. I wouldn't give up on it yet, but I would do what you're doing to make the car driveable. What other TB did you try and what computer did you use? Thanks for the update and continued G/L!

port injection is not an option. car has to pass calif smog. 87-8 is legal swap, so on in that direction..............

------------------
86 econo coupe-ground stompin' stroker 4 cyl, 88 rear cradle, koni's with coil overs, lowered 3 inches, mr2 spoiler on decklid. e-mail ossum1@hotmail.com

quote Originally posted by mrossum: port injection is not an option. car has to pass calif smog. 87-8 is legal swap, so on in that direction..............

You mean you can't port inject it because it wasn't offered in CA with port injection, or because you're using an older block?

It's really nice the way California emissions laws prohibit you from using an inherently cleaner setup (port vs. TBI) on a swapped engine.

(...but for those of us that don't live out on the left-coast...)

To ask again, does anyone have experience/links/info on converting the 2.5 to port injection?

[This message has been edited by TI_3VOM (edited 07-11-2003).]

you know that the 84-86 intake manifolds are different from the 87-88 manifolds, but for 84-86 you can put a holley tbi and is bigger and passes california regulations and it delivers 30% more airflow than stock, if you go to www.fierostore.com you will find it there but you are looking at about $300, its good replacement for stock.
-Roy

quote Originally posted by roys88fiero: you know that the 84-86 intake manifolds are different from the 87-88 manifolds, but for 84-86 you can put a holley tbi and is bigger and passes california regulations and it delivers 30% more airflow than stock, if you go to www.fierostore.com you will find it there but you are looking at about $300, its good replacement for stock. -Roy

i have a seriously ported head on this monster. the ports have been moved to match the intake pattern on the 87 up type gm 2.5 head.

air flow is not the issue, here. fuel quantity is where the problems are arising.

------------------
86 econo coupe-ground stompin' stroker 4 cyl, 88 rear cradle, koni's with coil overs, lowered 3 inches, mr2 spoiler on decklid. e-mail ossum1@hotmail.com

quote Originally posted by mrossum: i have a seriously ported head on this monster. the ports have been moved to match the intake pattern on the 87 up type gm 2.5 head. air flow is not the issue, here. fuel quantity is where the problems are arising.

You have given me a new project to work on. I don't know if I should curse you or praise you

OK I see it know, Get PoSE done, then do 2m4=8 and after that only one thing left! Archie! Oh wait I could also do a Turbine !!!

------------------
87 2M4 5 spd Daily Driver with working A/C!
86 "PoSE" Needs every thing but 4 NEW Tires!!!
http://home.cfl.rr.com/fierose

have the 87 intake on car now. am still wresling with wiring for the tbi, iac and tps. should have it wired shortly. still don't have the struts shortened yet. wife and daughters talked me into building a life size play house in back yard. has taken all extra money and time. will get back to monster before long.

------------------
86 econo coupe-ground stompin' stroker 4 cyl, 88 rear cradle, koni's with coil overs, lowered 3 inches, mr2 spoiler on decklid. e-mail ossum1@hotmail.com

Why is everybody using the 3.0L Mercruiser crank? Is it just because it gives a larger stroke? I would like to build my 2.5L up, but I have a limited budget, so I dont want to do much expensive machining, I was looking at a casting #311 crank, which I have heard is a direct replacement. But is is heavier, and stronger than the stock crank. Also, what is a good compression ratio to aim for? 10:1? I want to use 350 pistons in this motor.

------------------

mrossum, we are all behind you bro and waiting anxiously to hear some good news on your quest to successfully build a big bad iron duke

I would love to be able to tear Jordans Green beasts iron duke down and really pump it up some:

His engine looks sweet and amazingly has a lot of power for a lowly 4 banger but still.....
Please keep us updated, and maybe pics at some point of part of the build up would be great.

Steve

So what happened?

Where are these dyno results????????

JM

quote Originally posted by Slammed Fiero: This was 9 months ago so where are these promised numbers and also did you win that race and what was it against??? JM

life size playhouse has taken ALOT more money than originally planned. haven't touched car in quite some time. will get back to it soon.....

------------------
86 econo coupe-ground stompin' stroker 4 cyl, 88 rear cradle, koni's with coil overs, lowered 3 inches, mr2 spoiler on decklid. e-mail ossum1@hotmail.com

hey man i give you 2 thumbs up for attempting this project, please dont let anyone talk you to doing a motor swap keep it up..

------------------
85 fiero se soon to be custom

www.fibersmith.net
a great place for your needs, and it looks great too

for great rim repair-- $75.00 with power coating
http://www.angelfire.com/biz/wheelrepair/location.html

kaBUMP!