quote Originally posted by alienfiero: Pontiac use to make a duel over head cam conversion for the iron duke. And a magnesium block also.

Actually, it was Cosworth that made the conversion. There wasn't a magnesium block involved in the SD program.

Nate

I saw a article in Hot Rod Magzine 10 + years ago. But because most people like to stay away from magnesium , it may not have made it into production. But you can get a aluminum SD block, ref. GM power book, not made by GM.

quote Originally posted by alienfiero: I saw a article in Hot Rod Magzine 10 + years ago. But because most people like to stay away from magnesium , it may not have made it into production. But you can get a aluminum SD block, ref. GM power book, not made by GM.

Actually, Kansas Racing Products are the only ones licensed to make the SD block. It isn't even identical to the GM desigin, and they make them for using SBC and SBF heads, primarily. I was up at their shop a couple of months ago, those blocks are insanely overbuilt. They look like they belong in a tank. There were not any aluminum Pontiac SD4 blocks that were licensed from GM. There were aluminum Fontana and Chevy 4cyl blocks made, though.

My information was from the 2004 GM power book. And they said they don't make SD blocks anymore. Also GM dose not take any responsibility on what KSR offers in SD blocks or warrentee them. But sbc heads are much better.

Duke Power!

------------------
1984 Pontiac Fiero 2M4 - 88 Formula Front End, Roof Wing, JVC Stereo, 215/60R14 Cooper Cobras
Drop me a PM about which engine swap to do. 3800 S/C or 3.4 TDC

Hey mrossum, I was wondering if you could help with a problem I have. My billet SCAT crank has the same seal type as the 153 crank that you used, 2-piece with a SBC crank pattern. What adapter do I need to adapt it to the 1 piece seal on my Pontiac Super Duty block?

Nate

quote Originally posted by FastIndyFiero: Hey mrossum, I was wondering if you could help with a problem I have. My billet SCAT crank has the same seal type as the 153 crank that you used, 2-piece with a SBC crank pattern. What adapter do I need to adapt it to the 1 piece seal on my Pontiac Super Duty block? Nate

place called Nu-Tech Machine in el cajon/lakeside, ca has the adapter in stock. the guys name is Britt. 411 will have number. area code is 619. i have it, but it is packed away in file in rafters. tell him that charley from Quality Truck had you call him.

Thanks a bunch. I just talked to KRP and they still have a couple that should work. If it doesn't though, I'll give Nu-Tech a call.

Thanks
Nate

Any update?

quote Originally posted by Toddster: Any update?

Ditto/bump!

[sorry, double post]

[This message has been edited by mrossum (edited 02-17-2005).]

good thread, it outlived some of those who posted in it. worth a bump (so i can bookmark it).

------------------
John DuRette
Custom 85 ; 87 Coupe in the driveway. "Kinda makes you nostalgic for a Members Only jacket"

When high octain gas was readily avaible at every gas station, (pre 1973) 11.5:1 was kinda high for a daily driver. With that in mind, make sure you do your dyno runs with a wideband readout to see what your A/F looks like everywhere. I'd bet you're going to need to change your chip to adjust timming and fuel deleivery. I too, like to see people make power where others say it can't be found or is not worth doing. Guss I'm still just an old hot rodder at heart. Good luck with the project.

>ahh, ahh ahh ahh - stayin' alive, stayin' alive!<
I keep visiting this thread and have some more thoughts, just 'cause this seems like a cool excersice. The stroker crank looks like the cost effective displacement solution on the duke. I wonder if there is a way to keep the compression to 10:1 for pump gas? I saw someone above consider the 87-88 duke harmonic balancer, and though my 87 doesn't have the in-the-oil-pan filter I suppose it is not the duke with the counter balance weights, so perhaps the 'improved' balancer is a plus? I seemed to miss whether the Nova crank needed a custom flywheel or not, I got the impression the Merc crank would. I also saw that the Astro van block (I was thinking S-10 block) would be the ticket, of course the starter would have to be adapted and the FWD water pump swapped. I also seem to recall that the later (87-88) Duke had a much larger CFM intake/TB stock? And after reading through David Lane's (Ogre's) Cave articles there seem to have been some Duke motors rated at a little over 112 HP from GM. Not that that is an enormous change, but I wonder what the changes were., and if those parts could be used here without breaking the bank... manifolds, electronics - whatever.
Last, can anyone point me to the 'Duke Owners List'? I distinctly remember seeing that once upon a time...

here is the car about 2 hours after getting it back together this last week. pulled the stroker crank out of engine, and put everything else in my 87 dis engine. on the maiden shakedown run, fuel line split and poof.........think it might be time to give up this pipe dream.........

quote Originally posted by mrossum: here is the car about 2 hours after getting it back together this last week. pulled the stroker crank out of engine, and put everything else in my 87 dis engine. on the maiden shakedown run, fuel line split and poof.........think it might be time to give up this pipe dream.........

Holy Crap!!! I hope your ok after that. Before I get my car back on the road I was going to buy a fire extinguisher just in case. Now I definatly am.

Josh

That's really a shame, but the car isn't a total loss. You should be able to bolt on a new rear clip. I'm sure there are plenty around from people doing fastback conversions. How did it run while it ran?

quote Originally posted by mrossum: here is the car about 2 hours after getting it back together this last week. pulled the stroker crank out of engine, and put everything else in my 87 dis engine. on the maiden shakedown run, fuel line split and poof.........think it might be time to give up this pipe dream.........

First of all, sorry about your loss! That looks like a nice ride (past tense)

Well, when you take things apart, we would like to see pictures of what this crank machine work was and what the adapter looks like. I have a stock 87 DIS crank in the basement and the 499311 crank that is supposed to be the "good one" for performance sitting right next to it, and I just can't see for the life of me what it takes to make this work. It looks like you would have to ADD material to the marine or 499311 crank to make all this work! This is not to mention the extra "lip" on the 499311 crank. If you give up on the dream, at least send the key components on to one of us to try and make things happen, although maybe at a lower CR and with a MS for management instead of GMs TBI. I wish I were in CA so I could see your work, it looks like a nice car before the uhh, "typical 4 cylinder thermal event" took place.

Kurt

quote Originally posted by avengador1: That's really a shame, but the car isn't a total loss. You should be able to bolt on a new rear clip. I'm sure there are plenty around from people doing fastback conversions. How did it run while it ran?

car is total loss. completely melted the middle of car. cost a fortune to replace everything. am completely giving up on this project. would be able to help in any way i can for anyone who wants to pick up where i left off. to all of those who offered encouragement and assistance, thank you from the bottom of my heart...............charley j

car ran exceptionally well for the few hours it ran. didn't really lean on it. was going to be nice till it was broke in. such as life...........

[This message has been edited by mrossum (edited 12-04-2005).]

quote Originally posted by KurtAKX: First of all, sorry about your loss! That looks like a nice ride (past tense) Well, when you take things apart, we would like to see pictures of what this crank machine work was and what the adapter looks like. I have a stock 87 DIS crank in the basement and the 499311 crank that is supposed to be the "good one" for performance sitting right next to it, and I just can't see for the life of me what it takes to make this work. It looks like you would have to ADD material to the marine or 499311 crank to make all this work! This is not to mention the extra "lip" on the 499311 crank. If you give up on the dream, at least send the key components on to one of us to try and make things happen, although maybe at a lower CR and with a MS for management instead of GMs TBI. I wish I were in CA so I could see your work, it looks like a nice car before the uhh, "typical 4 cylinder thermal event" took place. Kurt

i did not use the stroker crank in this engine. you are correct. it would not work. had to use the stock dis crank for the crankfire pick up to work. everythjing else from stroker motor went into this engine. did have to change pistons, but stock mercruiser 181 flat top pistons worked well for the 9.5 to 1 compression i wanted. i do still have the stroker crank, and will try to get a pic posted this next week, if interested in seeing it.

this is still a great thread and not worthy of archiving.. yet.

If anything can be learned by this... it's... "DON'T RUSH...."

Always take your time when putting a motor back together. Imagine all the money spent and basically wasted because of this. Whenever I first start a car for the first time, I usually like to let it sit and I ALWAYS have a fire extinguisher around.

A lot of people say I worry too much, or that I'm being too anal... but you know what? It's better extra safe, than extra sorry.


I don't mean to rub it in by saying that... but hopefully everyone else here (including myself) will learn from your misfortune.


Something like this REALLY sucks....

By the way, if you live anywhere near Fort Lauderdale, I have a PERFECT white Notchback rear quarter surround panel in mint condition.

------------------
Todd,
2006 Pontiac Solstice
2004 Volkswagen Beetle Convertible (Wife's Car)
2002 Ford Crown Victoria LX
1987 Pontiac Fiero SE / V6 5-Speed
1987 Pontiac Fiero SE / V6 (3.2L) Auto
1984 Pontiac Fiero 2m4 SE
1981 Pontiac TransAm (Olds 455BB)
1973 Volkswagen Type-2 Transporter

sorry to here about your car

i have a 2.5 on the stand mine is a little difernt here it is

1978 2.5 duke block sbc bell
153 crank
153 marine head int. & exhaust on the same side 202 160 valves
chevy 250 I6 rods w/ arp bolts
ford 360 20 over kieth black hyper.pistons (ya its 70 over block) 12 to 1 comp.
cam not sure on the size yet
holley 650 double pumper carb
custom intake for 4 barrol carb

this motor is going in my s10 low rider so i can spank some V8s

btw i have a new 2.5 head and intake w/ nos fogger and holley big bore tbi for sale if any one is int please pm me

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

86 coupe with a 2.5 w/5speed droped on 17s 75 hp nos fogger wet kit big bore holley throtle body right now it is under going full custom fiberglass dash and sub boxes inside. outside giten rid of the belt molding full costom paint. should be on the road in summer of 2006

boy do i REALLY miss this car. might have to get another one and start over.....

This thread has definitely been "fuel for my efforts". I have always been a mouse motor builder. I have a 1.3 in my Suzuki Samurai that stock was 60HP and is now about 90. When you figure most indy cars have a displacement of 2.0L and produce about 600-900HP, thoughts are, a duke build-up CAN be done! I have been researching and aquireing parts for my "duke" and finding out alot of info from builders of engines for the "Pure-mini" race circuit. This is what I have found and with it being a DD, little mods for durability:
-S-10 block and head (re-drilled for starter)
-350 flat-top pistons
-Big-block roller lifters and pushrods to match
-88 crank ( I have an 85, but the mass of the crank helps)
-Port head and custom header
-Rods (still working on that for the strongest possible)
-Balance ALL components
-Increase fuel pressure and use a regulator to dial in best results(this way fuel mapping by the ECM is not needed)
-Mid range cam
-Low tension rings(cylinder walls will last alot longer)
-Use a remote vac valve(electric) for the EGR
-no cat, hollowed out or high flow design
-A/F ratio gauge to dial in F/P
I think this engine will be reliable and good for around 150HP. Since the bottom is stronger this way, nitrous can probably be added without much ill effect. I have thought long and hard about the 3.0 crank, but the compression ratio would be to high. Flat-tops will bring it to about 10.2:1.
I will kep you posted!

------------------
carpe diem

This isn't a pip dream, I'm ogin to map out a 200hp Duke, but no guesses as to when. I just read through this thread, as i'm nearing rebuild time for my duke, and see this as a reasable achievement. I'm going to base my build off the Mercruiser Crank.

This appears to be a sad ending to a very aggressive project. Perhaps the engine and tranny can be salvaged. Duke engined Fiero coupes are not the ones in high demand and you should be able to replace the car for a moderate cost. While I'm not a big proponent of hot rodding the light duty Duke engine, it's nice to see a project that takes a different twist. Look for another coupe and just throw the powertrain back in. I often see these 4 cyl. Fieros with blown engines sell for just few hundred bucks and often under a thousand in running shape.

------------------
87GT 3.4 Turbo- 0-60 5.2 seconds -Best
Engine Controls, ECM goodies, Chip
re-programming & odd electronics stuff

I think the reality is that the duke has many limitations, between poorly balanced components, weak block/heads, and an odd displacment (off square) I think the best way to achieve maximum duke power, will be to limit RPMs, and work at the low torque, which the motor is inherently good at. Also to steer away from high compression ratios, and forced induction. The motor wasn't meant to dissapate that type of stress. I'm betting a well put together, reliable duke could be in the 140-160hp range, with RPM capped at 5500ish. I think this build shows the extreem, and failure of the economy duke.

I think i recall the race superduty injected 2.7 engines in the IMSA Dole Huffaker fieros making 275 hp at 6000 RPM
for about 30 hrs then rebuild time. On a side note I know someone in Toronto that has two of them, never been run..
Kinser injection and all. They were a SD dealership's display engines and they were almost complete.
*Grins soooo evily (no not me... yet ?)

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

GT just waiting for the conversion
84 Fiero Turbo Vortec 4300 Phantom GT
L35 block, Syclone Intake and ECM
T31 turbine with T04B S3 compressor
super T61 waiting for next winter
www.cardomain.com/id/vortecfiero
Murphy's Constant Matter will be damaged in direct proportion to its value
Murphy's Law of Thermodynamics Things get worse under pressure.
Arthur C. Clarke "Any significantly advanced technology is indistinguishable from magic"

Wow that took a long time to read! Hey man sorry about your bad luck, such is life! I did enjoy the read as I just rebuilt my 84SE engine. I had a cracked head on mine so I went to the ol pull a part and picked up another head for $15 off an 86 Celebrity wagon and had a valve job done. Dunno how well it flows compared to the stock one. I bored my engine .030 and put new pistons. Seems to run pretty good but I agree I'd love to have more power. Since this car is my daily driver I think I'm gonna leave most things stock on it. i think I may add an MSD box and maybe a hotter coil to the ignition. Possibly even experiment with different injector sizes since I have a few laying around. I love the gas mileage and it's cheap to insure. I'd love to see someone succeed making a lil more power for some of us low budget guys. Wanted to share a couple thoughts on the duke though. 1. Don't wind the engine up too much, it is what it is, definately not a barn burner! 2. Dukes are noisy no matter what you do to them, it's just the way it is!! 3. Keep the oil changed and keep up your regular maintenance, it'll pay off I swear. 4. No matter what engine you choose keep in mind you are behind the wheel of America's ONLY mid engined sports car, You can have fun with 90hp, or 900. It's still a Fiero and despite all the different views we all love these cars!

Keep it out of the ditches y'all!
Jeremy

quote Originally posted by vortecfiero: I think i recall the race superduty injected 2.7 engines in the IMSA Dole Huffaker fieros making 275 hp at 6000 RPM for about 30 hrs then rebuild time. On a side note I know someone in Toronto that has two of them, never been run.. Kinser injection and all. They were a SD dealership's display engines and they were almost complete. *Grins soooo evily (no not me... yet ?)

The super duty has little in common with the Duke. That is why it can be rev'd high and built to produce a lot of horsepower. On the other hand you can only make so much power with the Duke before it self destructs. Nothing wrong with a mildly hotrodded duke engine for a bit more exciting of a drive, but bear in mind that the duke has a thinwall light duty block. You can only go so far with it. As suggested, a modified Duke should be built for as much low end power as possible. Those engines just don't like high revs and staying below 5000 RPM is probably a good idea. I also believe that they can be safely boosted with 5 or 6 psi or boost ( and some fuel mods) as long as the RPMs are held in check. Hotrodding the Duke can be an interesting project but for the money you spend , the horsepower to cost ratio will probably be better with a V6 swap. You can buy a good used 2.8L for $500 or less and have 145 HP. You could spend $2000 hotrodding the Duke and still only end up with 125HP. If the Duke is what you want go for it man but if you want an opinion here it is.

------------------
87GT 3.4 Turbo- 0-60 5.2 seconds -Best
Engine Controls, ECM goodies, Chip
re-programming & odd electronics stuff

one question, what's the wieght difference between a stock V-6 and the L4?

Has anyone used the Mercruiser crank yet?

I need some specifics...

where would someone go to get the mercruiser crank?

I know it seems like a total loss, but your efforts have been appreciated. I posted a link to this thread in this thread

.....annnnd BUMP

quote Originally posted by USFiero: .....annnnd BUMP

WOW!!!

it has beeen a while since i thought about this project. am starting to get the itch again. might have to go get another 88 4 cyl cpe and try again...

Scratch the itch. The time is right. Find a coupe someone is giving up since its the end of the "fun" season.

You have really left a lot of us hanging. There are probably a hundred people or more who want to know what kind of numbers that setup would have run.

Do you have the compression height and stuff for the 181 pistons? Seems like they would lower the CR relative to stock pistons, unless mercruiser rods are shorter or the deck height is different.

Kurt