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| Super Duty Four Rebuild (Page 1/5) |
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FieroWannaBe
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DEC 08, 02:06 PM
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In November of 2015 I bought a black 1984 Fiero SE. After failing several times to have it shipped from NY to WI, my friend and I took a road trip and trailered it back during a severe snow storm.
The car had been sitting for some time, the engine had seized, the tires had all dry rotted, but the car was 95% complete. It has bad paint that has gotten worse in the past 7 years, there are a few damaged body parts, and a missing headlight motor.
I collected some parts over the last few years, but overall have avoided major work on it until recently.
The big selling point for the car for me was that it had a 2.7L Super Duty engine in it and a pile of receipts from the build, and only 3,330 miles on the Odometer! I won the Ebay auction for $1,575, and had it in my possession by the end of February 2016.
In my excitement for finding such a great deal I tried to compile all the information that I could about building SD4 engines. I bought magazines that talked about the engines, and scoured the internet. There is not a lot of open discussion on building these motors but enough data to pull something together. I was able to get at least a solid plan together for a more performance oriented engine build.
I'll follow up with more posts detailing my progress so far and the information I've gathered.
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1986GT 4-speed DOHC -> LS4 F40 In Progress
1984SE SD4[This message has been edited by FieroWannaBe (edited 12-08-2022).]
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FieroWannaBe
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DEC 08, 03:03 PM
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Background on the SD4 (or Super Duty Four) engine program with regard to blocks and heads as I have ascertained from my reading:
The Super Duty Four program started out with John Callies at Pontiac, and it came from the need for the Fiero to be the Indy 500 Pace Car. John’s Interview with Total Seal Piston rings is probably the best 1st source for information on the program. Find it here: https://www.youtube.com/watch?v=2qkJu83XIPk, I heard him speak at the 30th Fiero Anniversary show, and he is a great teller of stories.
Pontiac made the parts designed for the program available to consumers through their dealer network, and had many aftermarket companies produce parts as well, which were advertised through the Pontiac Performance Plus publications. This engine wasn’t available as an assembled unit, each one is uniquely built with an application in mind, by random engine builders throughout the country. Vanderley Engineering built the engines used in the Pontiac GTU and GTP-L race programs.
I have two versions of the Build Instruction booklet put out by Pontiac and Hot Rod Magazine at this time, the 1983 version (the same as the pdf version which is shared often), which covers the specific block I have very well, but the head detailed in that book (GM# 10027776, with casting number 10027775) is not very common. This head was quickly replaced by the 10031323 and 10031322 heads, they offered improved exhaust ports and EGR compatibility. The later version of the book which I just generously received from a member at SpeedTalk.com, is from 1985 and features instructions for the later Aluminum heads and a revised version of the block.
Part of the lack of concise information regarding the Super Duty 4 engine and program can also be attributed to its quickly evolving development, as the Pontiac Motorsports team made consistent improvements, with lessons learned in racing.
Earlier Blocks, 1027633, have 2.5SD cast into the sides, later versions, the PN stayed the same, were cast with Super Duty on the side.
Both have reinforced Pan Rails, and Deck surfaces, and partially siamesed bores. The later Super Duty castings have longer sleeves which can be seen from the bottom of the block, and Pontiac made longer stroke crankshafts available during that time as well
At some point Pontiac made the switch to a 5 cam bearing cam tunnel, I assume this lines up with the entry in the GTP-Light as power and speeds would have gone up, and the race SD4 motors started using roller cam bearings. Pontiac also offered Aluminum Super Duty blocks, 10049881, in the late 1980’s. The Aluminum blocks in a revised SBC and GM Metric bellhousing were available from Nick Arias Jr. until his passing and business closure. Sometime later in the 1990s, Kansans Racing Products took possession of the Iron Block molds and continued production into the early 2000’s ( PN 10093306), but they are no longer making blocks today.
The earlier SD2.5 Blocks 10027633/10027634 where designed and sold for use with 3.25 and 3.00 stroke cranks, it’s my opinion that the 5 1/8” cylinder sleeve really hits its usable stroke limit at 3.5”, and at that point you need very long connection rods to keep the piston pins inside the engine. I don’t have any idea on the sleeve length in the later version of the blocks, but the casting does have more material at the bottom of the bore.
The Super Duty Heads started off with PN 1027775/1027776 as a revised port heads with a close net shape to the factory X-Car heads (Pre-Fiero production). This head required a lot of machine work to assemble and put into race ready trim, due to being run on Pontiac Factory tooling. I don’t believe many were made and were quickly discontinued in ‘83. Then Pontiac Released 10031322 and 10031323, for bare unmachined and a machined iron head (with EGR). This head had revised intake ports, raised floors on the exhaust ports, and required less work to install on a Super Duty block.
Pontiac Developed several aluminum heads as well. The 10038433 head appears to be an aluminum version of the 322 head (with no EGR port), with bronze valve guides and hardened seat inserts. The 10045437 head had revised and further raised and enlarged exhaust ports. The 10049801 aluminum head has repositioned and raised intake ports combined with the revised exhaust ports of the 10049437 head.
All that established, I will start with the car and engine as I purchased them. I dug through the receipts I was given, and compiled a list of parts quoted, parts sold, and how this engine was built. This year I finally pulled the block out of the car, took the iron head apart and disassembled the engine.
EDIT: Head PN's updated to correct casting numbers[This message has been edited by FieroWannaBe (edited 12-27-2022).]
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fierosound
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DEC 08, 03:07 PM
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Spadesluck
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DEC 08, 04:16 PM
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RWDPLZ
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DEC 08, 06:15 PM
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| quote | Originally posted by Spadesluck:
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Ditto
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MarkS
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DEC 08, 10:17 PM
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| quote | Originally posted by RWDPLZ:
Ditto |
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3rd
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Raydar
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DEC 08, 10:30 PM
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I'm surprised the "775" head was not mentioned. I had one of those on a 2.5(?) SD that I owned for a while. It was a cast iron head that used the same gaskets as the stock Duke engine. Other than that, I know very little about it. But the engine itself was quite streetable. Probably made ~200 HP, with a 6000 RPM redline. Idled at ~900 - 1000 RPM.
This was a very early SD. Iron block and head. The car (an 84 Automoda conversion) was owned by at least 3 people before I ended up with it.
(It had gummed up Dellorto carbs on it when I got it. I swapped the Holley on, and was going to rebuild the Dellortos. Ended up selling the whole shebang.)
 [This message has been edited by Raydar (edited 12-08-2022).]
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FieroWannaBe
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DEC 08, 10:44 PM
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| quote | Originally posted by Raydar:
I'm surprised the "775" head was not mentioned. I had one of those on a 2.5(?) SD that I owned for a while. It was a cast iron head that used the same gaskets as the stock Duke engine. Other than that, I know very little about it. But the engine itself was quite streetable. Probably made ~200 HP, with a 6000 RPM redline. Idled at ~900 - 1000 RPM.
This was a very early SD. Iron block and head.
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Thats becuase I copied the wrong PN from my book.
The 10027776/10027775 was the original SD4 head, which did have more in common woth the stock duke than the later heads.
Ill update yhe summary above.
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Raydar
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DEC 08, 10:57 PM
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| quote | Originally posted by FieroWannaBe:
...
The 10027776/10027775 was the original SD4 head, which did have more in common woth the stock duke than the later heads.
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I didn't realize that it was the original head, but I'm not surprised.
But I really enjoyed that I was able to use factory gaskets and other stuff when I was changing parts around. Just made stuff easier for someone like me who didn't really know what I was doing, as far as the SD went.
I wish I hadn't had to sell the car. We were about to move, and I didn't have anywhere to store it. All I did was bolt on that Holley. Never did even the first bit of tuning. And it still ran like a striped ape.
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FieroWannaBe
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DEC 09, 09:07 AM
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Here are the original photos I saved from the eBay Listing:
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