So guys I blew my Duke but I'm not counting it out yet. I'm looking for any advice, information, or opinions for my plan. While most would rather do a swap, I'm wanting to do something not seen quite as often. I want to rebuild and beef up the duke. So here are my plans and you guys tell me what you think!

.497/ 280 Cam (Fiero Store)
Comp Springs/ Retainers
Shaved/ Resurfaced Head
3 Angle Valve Job
Pro Pistons (fiero store)
Bore over on the block (not to sure how much though.... advice please)
Dropping the Cat
Flowmaster 80 Series w/ dual outs.

Eventually a tuning
So if anyone has any advice for me or even an HP guess for what i might have then let me hear it!!

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Tristan
84 Fiero SE

If you run a search on the Duke you'll see lots of threads on the subject. It has been flogged to death as it were. In short, the engines are not good candidates for souping up. Weak bottom end.

If you want a 4 banger, try a Quad 4 or Ecotech.

Arn

https://www.fiero.nl/forum/Forum2/HTML/086221.html

This is my thread, I'm going to be doing this in the winter. Rebuilding a 86 2.5 for my 84. Reliable is the main thing I'm going for. Stronger parts, etc.
The parts you posted are good. I'm not sure about the boring or anything. I'm going to put in Chevy 350 pistons. Roller rockers. Fierostore cam. 87 rods. Aluminum timing. And MSD ignition.
Every part will be cleaned. (hot tanked). Intake will be carbon free and like new. I'm going to try to gasket match it, and port what ever i can, for more flow.
I don't know how much hp you want. My goal is 100hp. I'm sure I'll pass it and get 110 or so. But i have no idea. I could be way off and not get any power increase. Its just a guess. I just want it to last and be reliable. I will do a before and after dyno. So people can see how much power i got.
Good luck!
Brian Maxwell

Tris: When ever we start a project we consider the cost vs results ratio. In other words cost per HP. Quite frankly the Duke is an economy engine. You may be able to build it for 120 HP and be able to keep it together but the Duke is not a strong platform for performance. Sure you could use small block pistons and stronger rods but the block is a really lightweight piece.
At the shows all of the Duke guys usually praise the engine for it's reliability and economy. Reports of up to 39 MPH have been made and gas mileage is where the Duke shines best. It's an engine for economical transportation, so forget about racing it and choose an engine suitable for your needs.

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87GT 3.4 Turbo- 0-60 5.2 seconds
2006 3800SC Series III swap in progress
Engine Controls, PCM goodies,
re-programming & odd electronics stuff
" I'M ON THE LOOSE WITHOUT THE JUICE "

Don't bore it its weak as it is.

Just a few weeks ago a guy cracked the block from running with an overbore. So I say go for the Duke beefing, but cut the boring, I'd hate to see you with a cracked block

Racing it is definitely not the plan, I should have put that forth. I'm just looking to build it up to respectable HP... considering what it is. Nothing huge, nothing to race but more or less for my own satisfaction. But i do appreciate the advice that I am getting so keep it coming.

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Tristan
84 Fiero SE

quote Originally posted by Dennis LaGrua: Tris: When ever we start a project we consider the cost vs results ratio. In other words cost per HP. Quite frankly the Duke is an economy engine. You may be able to build it for 120 HP and be able to keep it together but the Duke is not a strong platform for performance. Sure you could use small block pistons and stronger rods but the block is a really lightweight piece. At the shows all of the Duke guys usually praise the engine for it's reliability and economy. Reports of up to 39 MPH have been made and gas mileage is where the Duke shines best. It's an engine for economical transportation, so forget about racing it and choose an engine suitable for your needs.

I agree,your best bang for the buck would be an engine swap (unless you want the stock engine).

For the time being I want to keep my stock engine. I'll wait till i can get my hands on a 88GT for a swap. For the mean time lets keep on beefing the stock engine.

quote Originally posted by NeoTristan: For the time being I want to keep my stock engine. I'll wait till i can get my hands on a 88GT for a swap. For the mean time lets keep on beefing the stock engine.

If you insist. Small block pistons, mild cam, larger throttle body, ported heads and a free flow exhaust should get you 120HP. Just build for max power at low RPM's , drive it conservatively, don't open it up too often and pray for the best!

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87GT 3.4 Turbo- 0-60 5.2 seconds
2006 3800SC Series III swap in progress
Engine Controls, PCM goodies,
re-programming & odd electronics stuff
" I'M ON THE LOOSE WITHOUT THE JUICE "

Here's a web site that sells Duke parts that can get you up to 180 HP.

http://www.amotion.com/p4.html

I've done a ton of thinking on this subject, but to even make 200HP, it seems that isn't possible. For the cash needed to make even 130HP, it wouldn't be cost effective. And, for me anyway, 100HP isn't worth the effort and monies needed. For a reliable 115HP, I'd have to at least get a balanced crank, like the Mercruiser crank. But then, it gets back to cost>worth. I've toyed with the thought of some kind of crank girdle to tie the bottom end together with the oilpan rail for that little more strength, but that is almost impossible too. I'd upgrade to a 90s S10 head, intake, ECU, injector with maybe a shorty header. That should get you up there over the century mark, and with a decent chip reprogramming, you should see over 110HP considering I've seen people say the 93 S10 Duke already makes over 100HP stock, so I'm being a bit conservative, altho GM has been known to underplay engine ratings. Take the CobaltSS for instance. But, yeah, I'd go the top end from a 92-93 S-truck Duke with related components.

Ok first the vent then the specs. The guy asked like so many before What he could do to a particular engine and instead of answering his question the only thing most say is "swap" it. I remember this happeningg to almost everyone that brings up modifying what someone else deems an inferior engine. Dennis the Odd thing is you went thru this when you started your Turbo V-6 and everyone said you should just do a V-8. Remember that? My point is that if someone wants to do something either help or stay quiet rather than bashing what someone wants to do, because you wouldn't like them bashing you. BTW Dennis this is in no way aimed soley at you. I have seen this done to too many people on to many boards.

Now that my rant is over here is what I will say. HP is not hard to find. Fact is the SD-4 made 232 streetable hp in the Indy pacecar. Like it or not the stronger SD-4 block does not help it produce more HP. Just handle it. The SD-4 head and intake i am sure do. But for arguments sake I will leave any and all SuperDuty parts out of my specs.

Blocks---Try and find a "T" block if you can. It's a bit better. I have one in my wifes car. Not sure what they normally come in as I found mine in a Fiero. guess it was a rebuild or crate motor. S-10 blocks will not work as they do not have provisions for a side mounted water pump. But I have heard there were some Astro vans that had Dukes(mostly company vehicles) which had the stronger block(s-10/SD-4 Style)and the side mounted water pump. Stock will be acceptable if nothing else can be found. Do not bore the block.

Cranks---You can use one out of an 87 DIS engine as it is stronger. You can also use a Marine crank although some machining will probably be necessary. Now before anyone says these are too expensive i'll have you know I have two of them in my garage that I got for $50 each. And since i am suggesting this option it would be unfair of me not to tell you how to get them too. Simply go to a boat marine shop and ask if they have any junked ones laying around. When they replace them they generally get rid of them as it cost too much to ship them back to the manufacturer so core charges don't usually apply to the dealer. I got 2 complete blocks this way. One was not winterized correctly and had a busted block and the other had another problem which I can't remember at the time. Both cranks are super and I have heard that they are capable of 10,000 rpm inracing engines. Now a better than stock crank will strengthen the bottom end.

Heads---Stock with minor porting and polishing is ok. I would also suggest you get the SuperDuty head gasket. Keep in mind that there are two different versions of this gasket. One for cast iron heads(the one you want) and aluminum heads. You can also use the cool roller rockers. I bought ones for a BBC but i hear there are some from Ford that work. You will need to have your head machined for bigger studs to use these rockers and will possably need longer pushrods.

Cams--- You can call any cam company and tell them exactly what you want and they will cut you a cam. Not like the old days where cam manufacturers had certain grinds in stock. Got mine from CompetitionCams.

Intakes. Stock would be ok. The Holley or Edelbrock would be Better. The Edelbrock is a bit of a weird intake as it is a dual plane TBI intake with smaller than stock ports. And threaded holes on top of the runners, which I think are for water injection. You can also get a Offy 2or 4bbl intake.

I will try to post more tomorrow as I will get all the part numbers of my wife's build.

I would love to see a recipe (with costs) for a higher HP Duke build with a dyno sheet to back it up. There is interest.

quote Originally posted by The_Stickman2: Ok first the vent then the specs. The guy asked like so many before What he could do to a particular engine and instead of answering his question the only thing most say is "swap" it. I remember this happening to almost everyone that brings up modifying what someone else deems an inferior engine. Dennis the Odd thing is you went thru this when you started your Turbo V-6 and everyone said you should just do a V-8. Remember that? My point is that if someone wants to do something either help or stay quiet rather than bashing what someone wants to do, because you wouldn't like them bashing you. BTW Dennis this is in no way aimed soley at you. I have seen this done to too many people on to many boards.

First off welcome back to the Fiero scene. As for a Duke build there are few that have gone through it like yourself, so we should take credence in what you are presenting.
I am certainly not trying to bash anyone who wants to do the Duke build, just trying to get his expectations in line with the engine platform that he intends to build upon, and the money that it will take to arrive at the desired result. Actually I liked the Duke performance build that you and Dawn did, as it was a refreshing change from what we normally see. Apparently it has stayed together so you used the right formula.
As for the V6 vs V8 thing, that argument will be with us for as long as there are Fieros, but if there is a lesson to be learned; you can only go so far with any engine 4 , 6 or 8.. My 3.4L turbo was fun to build and drive but having nearly maxed out what could be done, a 3800SC w a new 4T65eHD now sits in my Black 87GT.
BTW, hope to see you back at Carlisle in 08.

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87GT 3.4 Turbo- 0-60 5.2 seconds
2006 3800SC Series III swap in progress
Engine Controls, PCM goodies,
re-programming & odd electronics stuff
" I'M ON THE LOOSE WITHOUT THE JUICE "

If block good replace parts that need replace with performance parts.bore the the cylinders mimimum.just enough. I would get 88 block!!You can not use s10 head only 87 88 fiero will accept,, this is the single best modification you can do to the duke,this head delivers better horse power,better miles per gallon ,better cooling and more efficient engine,,DO NOT PORT the s10 HEAD,my duke responded well to removal of cat ,installed cherry bomb quiet at idle great sound between 2000rpm and 4500 porting 84 to 86 head matching ports and header will make big difference,, I have a V6 now but the duke is the best engine for all around use with $4.oo gas in our future.do mods that increase performance and add little stress to engine first an 84 duke with a few mods will jump a V6 off the line and stay with a V6 untill 40,,after this break out the cash or marry the rich ugly girl..you should concentrate on the head,intake and outlet see how you like this .1.5 rollers,reseat valves new oil seal, if serious machine shop basic valve job ,the valve stems fit must be factory specification...if your engine uses oil and you do not plan to rering at this time remove head hand lap valves do not use drill to lap in ,,use suction cup method rotate as you grind, replace valve seals, clean head like it was boiled..check in direct sunlite for cracks imperfections,, you can get cheap performance gain before you jump in deep end ,of money pitt, think big,, perform small for now,, I love swaps but am to lazy for the head aches if you even have one thought to do swap,now is the time,just the inkling,1% then in future you will want swap this is not the south beach date with cameron diaz some say it is ,unless you can hear engine run you "must" disassemble ..some idiot put an olds V 8 in a 49 ford and the engine cranked right away with a loud rod knock,hmmm wonder who that was

[This message has been edited by uhlanstan (edited 09-28-2007).]

Ok here are those part numbers I promised.

Comp Cams 52-000-5
260-8/260-8 h114+4
serial# J 4037 03658464155
Valve springs
988-8
1.400 2 spring assembly
lifters
864-8
Pont 151 hyd lifter

Crane Cams
Energizer rocker arms BTW while looking for the box for the part #'s I found said box and low and behold I still
13744-16 have 8 NEW rockers in the box. Anyone wanna make an offer?



Fel-Pro head bolt set
ES72733 future # 21-1117

King Bearings
MB5532AM 010
MS1733 *6689M

Melling oil pump oil pick-up screen
62-CS1
Melling oil pump
M-62CHV

Cloyes Gear
Alloy gear set
Have no idea what the part number was
Just get one as the fiber gear will give up on you when you least want it to.

Badger Pistons "Diamond Turned" Yes I realize I went with a .030 over bore when i have been saying not to. Don't remember why I did. Maybe I needed to in order to use this particular block.
P483-030
Federal Mogul sealed Power( i think these were the piston rings)
E-381X 30

Not sure what rods I used but I believe they were Badger's too.
Sorry no part #

Super Duty Head gasket(cast-iron head)
10031324

Parts I have but were not used in this build

B&B main cap studs
SD-4 engine 10 pcs
10045408

Dynagear
Alloy gear set
221-2525S

[This message has been edited by The_Stickman2 (edited 09-30-2007).]

ooooh Im excited need roller rockers for next project !! unfortunately I,ve reach a point where I will not spend the time of day,have V 6 now..what ratio are rockers?? some one snap these up

quote Originally posted by uhlanstan: ooooh Im excited need roller rockers for next project !! unfortunately I,ve reach a point where I will not spend the time of day,have V 6 now..what ratio are rockers?? some one snap these up

They are 1.7 ratio rockers. I also have some used Crane Gold rockers. Not sure if it is ok to re-use rockers or not.

BTW 2 things I forgot to mention. With those pistons my compression ratio came out to be 10.1to1. And with those rockers you will need to have the head drilled and tapped for larger studs. And I also needed different pushrods. So you would need to have the size checked. I know my machinist just looked in a reference book and found a set that worked. I think he said they were from a Buick or Oldsmobile V-8 but I am not sure anymore.

I would love to see someone actually do this stuff if it is doable and drive it and tell us what happens.

Well, I am loving all of the detailed information. It is really helping out, I'm also assuming that the smaller crank in the picture is the marine crank (i have not gotten into the block yet.) I have decided that I am am going to try not to have a huge jump in compression and that I am going to bore over only if i have to. (it would be minimal) As far as a project like this working.... I will have full pictures, dyno sheet (just for SnG's) and maybe a video available.....

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Tristan
84 Fiero SE

quote I'm also assuming that the smaller crank in the picture is the marine crank

The puny looking crank is a stock Duke crank, as used in an 84-86 Fiero.

[This message has been edited by pswayne (edited 10-01-2007).]

2.5---someone has done it. Me. That's why I posted all the part numbers of my build. How does it run? Pretty good. Seems like it has a bunch more HP. How much? Dunno. I'm not going to make wild claims and have'nt had it on a dyno to know for sure. It also doesn't have a lot of miles on it because of oil leaks. I seem to have this problem on any car and engine I own not just Fiero's and Dukes. We ended up having to remove the engine to replace the oil pan gasket and rear seal(weren't sure which it was). And since I have health problems my wife has to work extra hard, otherwise she might have the energy to finish putting back together. Well that and the money to finish putting it back together. Now we have an Edelbrock Intake waiting to go on it which should give more hp(wish i had a Holley TBI for it) . The intake is odd though in that the ports are smaller than a stock intake(hight velocity charge?). If I get my disability maybe it will get back together. We also need to figure a way to mount the EGR remotrely as it won't fit with the SD-4 valve cover which I want to use.


pswayne---You are correct the bigger one is the marine crank. Again you would never believe how heavy this thing is.

The crank is a good one. It is the earlier one that only really requires a 2 piece rear seal adapter if i remember correctly.

The engine won't be much use. It is the old 151 engine which I don't think parts can carry over from.

The head is unusable. Non-crossflow and just different.Only thing usable things in these engine are the crank and maybe the pistons and rods. BTW they made like 160HP and were more heavily stressed than street engines.

"Reports of up to 39 MPH have been made and gas mileage is where the Duke shines best." -Dennis LaGrua


HOLY SMOKES!!! 39 MILES PER HOUR??!

quote Originally posted by MordacP: HOLY SMOKES!!! 39 MILES PER HOUR??!

I don't believe it! I'd have to see a time slip at a track before I believe that ANY duke got up to 39MPH!

All joking aside, a "+" to The Sickman for posting great information on how to beef up the duke. I've seen threads in the past where people have asked how to beef up the duke, and the majority of the replies are "engine swap". It's great to see that someone has the knowledge and the time to pass the knowledge along.

You don't really need an EGR do ya? I suppose to pass emissions maybe. Hope to hear your mpg and 0-60 in the future. Cool that you actually did it! Also what was your total cost of parts?

quote Reports of up to 39 MPH have been made and gas mileage is where the Duke shines best

Actually I've had my 88 duke up to 90 MPH... . And as far as MPG, I've got up to 37. I could probably do 39-40 if I could manage to keep it to 55-60 on a long stretch of highway. But the darned thing always wants to go faster than that.

I know at stock HP I've had my 84 Duke wrap the needle back around to the zero, and the same can be said for the 88 that I had six or so years ago

Another interesting thing on Ebay:
SD4 Head

So I'm about to the point where im going to remove the engine... My genuine Fiero shop manual tells me to drop it with the tranny and rear frame... I just don't have the nice shop lift like shown in the picture. Any advice?

You must have very high in the air..pull trans bolt and find 2 long bolts you hacksaw the heads off.. this will assist you in remove and install .. ,if to difficult you can remove duke head then remove all parts you would remove for rebuilt and pull it out the top,, there are many post on pulling transmission,some on engine you need jack stands real secure ,better to have front end on ramps with brace to front end to secure something like truck backed to front,, you can pull whole assembly ,or separate depends on what you brung to lower engine trans and strength,don,t forget to drain oil first better to remove duke head easy to do,catalogue parts number push rods ,have box with holes waitinghave sections numbered for lifters even place guides back in proper order,even before you disasemble write down parts order,part of a rebuild is to make sure valve stems have proper fit,, ring lip MUST be removed,, basic valve job special performance job wasted on duke,,be precise in piston ring gap,EVERY RING,if worried about oiling lightly grease cylinders,ect..oil will absorb no sweat,,crank, pistons easy don,t skimp on stem clearance,don,t ham fist when using spring compressor..if porting head protect valve seats,if you do not boil head clean like it was steam clean,, an engine paint job is no different than car the prep is where the job is made..don,t let the coolant passage rust heat timing chain cover in sun cool seal in cold then drive in ,check head flatness on glass or known flat surface,,remove minimal to straight edge,block can be smoothed with glass grinding compound method,,use soft scrapers in my 20 years as a mechanic helping people at home biggest villains! dirt and metal scraper gouching, tearing,ripping gasket surface should be as pristine as you can do ,its why so many rebuilds leak,head gasket and valve cover gasket use liquid remover do not scratch cylinder chamber,again do not scratch combustion chamber this is 5% removal a pain,,rebuild a joy of tenderness and precission,follow manual double check all measurement,,rool pushrods on glass lifters clean clean clean do not drop do not scratch

quote Originally posted by NeoTristan: So I'm about to the point where im going to remove the engine... My genuine Fiero shop manual tells me to drop it with the tranny and rear frame... I just don't have the nice shop lift like shown in the picture. Any advice?

Do you have a cherry picker? If so you will also need and engine leveler(not expensive). then you can pull it out the top. Very easy. We have done it more times than I can count. You just need to remove the intake and exhaust manifolds. You can leave the exhaust manifold hooker to the exhaust, just hang it out of the way to the firewall. Then take the alt, and water pump off. Hook up the cheery picker/engine leveler, and unbolt the engine from the trans. the raise the engine(may have to wiggle the engine to get it off the trans) and as you raise the engine you need to use the leveler to angle the engine up. If you have more questions just ask.

[This message has been edited by The_Stickman2 (edited 10-02-2007).]

what do you mean by angle the engine up? and I have a 4-speed so how far from the tranny does the engine need to come? Will i have to remove the pulleys?

I'm a drop it out the bottom person. Too much work unbolting water pumps, alternator, etc.

quote Originally posted by NeoTristan: what do you mean by angle the engine up? and I have a 4-speed so how far from the tranny does the engine need to come? Will i have to remove the pulleys?

Ok, no you do not have to remove the pulley's. Just what I said and all hoses and wires. Then what you do is raise the engine up with the engine hoist and as you do this you crank on the engine leveler to raise the pulley side of the engine. Think of an plane taking off. If you have any more questions just ask.

Thought I'd reference the "Big Bad Duke" and "Better flowing Duke Heads" threads for you all.

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John DuRette
Custom 85 SE/86 GT
"Kinda makes you nostalgic for a Members Only jacket"