Alright, so lately I’ve been searching around and looking for different interesting engines to possibly swap into a fiero and I stumbled upon a super duty 4 head from I don’t know when.
The ad reads as follows “ Cylinder Head This 2.5 special aluminum cylinder head is a race winning design for the four-cylinder Pontiac aluminum "Super Duty" that's proven itself in IMSA road racing and Competition Eliminator Series. This rugged, lightweight head gives you Pontiac and NASCAR quality with plenty of extra metal, and proven performance with totally redesigned, super free-flowing ports. Oversize ductile iron seats . Intake volume is 178cc. This head accepts standard four-cylinder intake port centerline manifolds. “
I’m going to be honest, I don’t know much about these engines. I do know that they are a very good set up and are quite capable of power and being thrashed on.
What I want to know is that if this is something that I can bolt on to a stock iron duke, or if I need to do some machining on the block, or I have to have the super duty 4 block.
I also am curious to how I can make this work, if there is any way to get or make/modify parts for this thing so it can run.
Hopefully we can make this work, if you know of anyone selling any parts please send them my way!
The "Super Duty Four" was a high performance engine designed by GM to power the Indy Fiero and to be sold as a separate performance item.. It was never used in a Fiero production car. I don't know what head you are referring to but the Super Duty Four usually installs as a unit. If you want an engine swap you need to define your requirements and usage. Then it will be possible for the people here to make a recommendation. Consider factors like, weight, horsepower, torque, mileage, reliability, cost , size and ease of swap.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
I think it can be made to work, but you'll (I'm pretty sure) have to redrill the head bolt holes in the block, and use larger fasteners. Depending upon the casting #, you will probably need a special intake manifold and exhaust header. Now... if you get it to work, you will probably break the bottom end in fairly short order. That head will likely allow your engine to make at least twice the power that it was designed to. Think broken rods or crank, and ventilated block castings. It will probably go like stink. For a few days.
I have thought about similar mods for my 88 Duke, using a much milder cast iron SD head. This was with the full expectation that I would probably blow it up, at some point. Good thing I couldn't find one of those heads.
(I don't make these comments lightly. I used to own a Fiero with an iron head SD4. It probably made close to 200 HP. It felt as strong as my 4.9 car.)
[This message has been edited by Raydar (edited 09-11-2019).]
Have you read 2.5l myths and differences by strokerS10 ? The 437 head is the biggest with stock location ports. The 801 is the biggest but ports are raised and moved on the intake side. My 437 flows 305 cfm at .700 lift on the intake and 235 on the exhaust at .700. The 801 flows even more. Hope this helps some.
According to the talk that John Callies gave at the 30th anniversary, the Super duty 4 had identical bore spacings that the Iron Duke had and whatever else had to be the same so that it could be classed as a production motor. It was very close to being half of a 307 v8. They farmed out (get it?) the job of casting the blocks and heads to John Deere, the only way they could stay in budget. I don't know if anyone ever stuck a super duty head on an Iron duke or not, would like to see a thread on that.
The original iron duke 4 cylinder was made in the 60's and put in to Chevy 2's and some Pontiacs and gained a rep as being bulletproof. But it was never officially called the iron duke, that was the nick name that the magazine writers gave it. GM stopped putting it in cars but sold it to Mercury and OMC for use in I/O drives,usually with a 130 HP rating. Still being sold by Mercury and some were sold attatched to Volvo drive units. I think they now displace 3L.
[This message has been edited by wftb (edited 09-13-2019).]
According to the talk that John Callies gave at the 30th anniversary, the Super duty 4 had identical bore spacings that the Iron Duke had and whatever else had to be the same so that it could be classed as a production motor. It was very close to being half of a 307 v8. They farmed out (get it?) the job of casting the blocks and heads to John Deere, the only way they could stay in budget. I don't know if anyone ever stuck a super duty head on an Iron duke or not, would like to see a thread on that.
Wow, never heard before that any of the SD parts were made by John Deere. If true, very cool. 'Nothing runs like a Deere"!!
Going to need a 3.0 shortblock turning 7000 RPM and a big ruppity rump cam to take advantage of that flow.
A stock Iron Duck block will not survive that.
I helped build a stock block aluminum headed dirt engine once. The head was off a Jeg's drag car. We used 6" small journal SB Childs & Alberts rods, also used from Jeg's, narrowed .076". Well 7 rods as one fell out of their motor on the starting line. Yes we drilled the stock block for 1/2" studs. BUT PAY ATTENTION TO ME!!! The instructions with the stud kit tell you tp drill, from memory 1.5" deep, but if you do that on the stock block you will break through into the lifter gallery. Think water in oil. So you only drill to bottom of hole on the holes next to lifter gallery. Then shorten studs about 4 threads. You have to machine/narrow SB rod bearings also. I think we used 455 Pontiac pushrods? Flat tappet cam form Ultradyne. Big block chevy rockers although they weren't the recommended ratio for the cam. BB is 1.7, cam grainder said 1.55. The 1.55 were custom order at that time and EXPENSIVE. Diamond pistons. Don't have any info on valves/springs/retainers as they came with head. You MUST remove the oil filter bypass valve or it will get pushed up into oil gallery starving bottom end bearings...don't ask how i know.
I've driven one with a 258 and 4 speed. Also the Eagle SX/4. I did the engine/diff mounts for a small block Chevy into an Eagle... now my dad needs to do the exhaust, oil pan & transmission like he said he was going to...
