Thats a big dollar build and I do not dispute the power but notice that on the test a 5,000 RPM redline was used. Despite the power I don't believe that the work and cost per HP gained is a good value. .
------------------ " 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 didn't watch enough of the video to find out if that's a production block or not... There have been a few threads about building high power Dukes over the years. Even when the builder succeeds in making a decent number, the block gives up after not a lot of run time. Building a high power Duke involves taking the stock engine to a scrap yard and starting over with a Super Duty block.
Yeah - the point was to use a production block since the SD stuff is so rare. As I always say - if you are going to do engine mods - you should always do a full rebuild with high quality parts so that it doesn't fail.
This happens to be a block that is .060 over-bored to get close to 3.0L ...so it was clearly rebuilt...as it should be...
Yeah - the point was to use a production block since the SD stuff is so rare. As I always say - if you are going to do engine mods - you should always do a full rebuild with high quality parts so that it doesn't fail.
This happens to be a block that is .060 over-bored to get close to 3.0L ...so it was clearly rebuilt...as it should be...
Not what I meant. The production block--the casting itself--is not up to making decent power for any reasonable service life.
Not what I meant. The production block--the casting itself--is not up to making decent power for any reasonable service life.
Must agree with this, that the Duke block will not hold up making repetitive high power levels read by the engine dyno. This was an expensive experiment that only proves the power than can be developed. Over a longer period of time I have serious doubts about longevity not only for the block but also for the crank..
------------------ " 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 "
Turn the journals on the crank and face the rods. At some point I found h-beams that had the right journal width but can't find the part number.
Bore .030 over.
Half fill the block.
Head studs.
Copper headgasket or stack. Careful here. Make sure you calculate the compression and get the right thickness. Check your combustion chamber ccs after porting. My gasket thickness was .080 and put me around 9.5:1 with those +13cc pistons.
Port an S10 head with SBC valves or go SD if you can find one. You want a 90' if going S10, the later years are more work and the valve stems are different diameters than SBC valves. Early heads are garbage, don't bother.
Aluminum cam gear and turbo profile grind. Call Delta.
AFR and 5.7 injector.
Small turbo. I used a no-name ebay 18G I had from my old Talon. Certainly not the best choice but run what you have.
This forum is decades of talk about the Duke being a POS so literally no-one tries. I had about 15k miles on mine until I popped a piston it with a 100 shot of nitrous dry like an idiot.
Why would you do this? Because you have money to piss away. Better, easier and more fuel efficient ways to get 200hp.
A 200hp Duke is not a hard build. The block is fine.
This forum is decades of talk about the Duke being a POS so literally no-one tries. I had about 15k miles on mine until I popped a piston it with a 100 shot of nitrous dry like an idiot.
Why would you do this? Because you have
money to piss away. Better, easier and more fuel efficient ways to get 200hp.
I don't believe that anyone is calling the Duke a P.O.S. . What it was built to do, it does well. I doubt this performance high buck build that you outlined will result in more fuel efficient ways to get to 200HP. Regardless of the debate, people usually consider the risk vs reward factor before undertaking an engine build. For a four the Ecotec engines or the new large GM 4 are probably a more economical way to go.
------------------ " 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 "
[This message has been edited by Dennis LaGrua (edited 09-28-2022).]
That's part of the rebuild. On my 3.5 I am - you guessed it - half-filling the block. This is not rocket-science to people who rebuild engines for performance. 3.4 -> 3.5 = .120 overbore. I don't like it when things blow up.
It took me over-revving on a wet track twice to 8000 rpm to finally blow my rings just over a year ago. How many years was I racing for?
[This message has been edited by lou_dias (edited 09-16-2022).]
I respect what that guy did, take an engine he is not familiar with and do all those mods to "see" how far he could take it. I'm pretty sure he left a lot on the table because his valve timing was way off. I'm surprised on the cam specs he chose taking into consideration he is a professional engine builder.
I personally half filled on recommendation from a guy who built dirt circle track racers that used built up dukes. Does it need it? I have no clue, I don't know. It's so incredibly cheap and won't hurt anything, so why not? I attest the longevity to the new crank and rods. If you can fix a weak block with $50 worth of fill, it's not worth even mentioning.
Dennis, I think you misunderstood. I was saying building a duke is dumb and only something to do if you have money to throw away. There are dozens of better ways to make 200hp and also get better MPG
I personally half filled on recommendation from a guy who built dirt circle track racers that used built up dukes. Does it need it? I have no clue, I don't know. It's so incredibly cheap and won't hurt anything, so why not? I attest the longevity to the new crank and rods. If you can fix a weak block with $50 worth of fill, it's not worth even mentioning.
Filling the block is not to prevent cracking or blowing up the block. Its primary purpose is to give rigidity allowing overbored cylinders to keep their roundness while preventing shifting during the reciprocating movement of the piston/rod combo. If shifting of occurs then a loss of compression will follow during operation and the power will drop significantly.
[This message has been edited by La fiera (edited 09-18-2022).]
So, your one example is from a guy 20 years ago running 11.5:1 compression?
Time doesn't matter. Production Duke blocks have not gotten stronger in 20 years. I just know what I've read... but I'm not interested in doing the research on a Duke build.
Not sure what dog you might have in this fight, since you've already filled your block.
quote
Originally posted by La fiera:
Filling the block is not to prevent cracking or blowing up the block. Its primary purpose is to give rigidity allowing overbored cylinders to keep their roundness while preventing shifting during the reciprocating movement of the piston/rod combo. If shifting of occurs then a loss of compression will follow during operation and the power will drop significantly.
...what dog you might have in this fight? What are you fighting exactly?
A simple google search for engine block filler and you'll realize this is a common practice.
For people who just like to spend years throwing in ticking-time-bombs into their engine bays ... not so much...
I know block fill is a common practice... for blocks that have a high likelihood of breaking... like I said above... yes, filling the block is common practice.
Cool video. I like to see people doing things with the Duke. However it looks like that was a custom intake, a custom exhaust and unless I missed, they were a bit vague about what cam they had. So its not like many people are going to be able to replicate this.
I would love to see a video on the duke like the show Engine Masters ,where they take the duke, put on the Holly Intake and TBI and Dyno it. Then throw on one SD4 intake and/or SD 4 Head. And why not the Tri Y header too. Yes these parts are all rare, but they do come up for sale from time to time and an average guy could swap out the parts.
And my Quad 4 makes 180 HP stock. Interesting that someone spent a bunch of money to make a 172 HP from an iron duke. Basically a science experiment. Anybody that follows down that path is insane.
------------------ formerly known as sanderson 1984 Quad 4 1886 SE 2.8L 1988 4.9L Cadillac 1988 3800 Supercharged
And my Quad 4 makes 180 HP stock. Interesting that someone spent a bunch of money to make a 172 HP from an iron duke. Basically a science experiment. Anybody that follows down that path is insane.
The Quad 4 is a far better engine and a good choice for swapping, although I understand they are getting harder to find.
The modern equivalent is the Ecotec - stock turbo LNF = 260 or 290 bhp stock, and the blocks are good for around 500 bhp (I run a conservative 375 bhp and get 30 mpg when not in boost).
The Quad 4 is a far better engine and a good choice for swapping, although I understand they are getting harder to find.
The modern equivalent is the Ecotec - stock turbo LNF = 260 or 290 bhp stock, and the blocks are good for around 500 bhp (I run a conservative 375 bhp and get 30 mpg when not in boost).
That's not much different than me saying my 2.8 gets 40mph going downhill. Last time I looked, the N/A ecotech does not make anywhere near 220 ft*lbs... Also, the dyno was not smooth. The graph looked real ugly to me. All they were playing with was timing. Next step would be fuel adjustments. I don't know the people involved in this rebuild but I don't doubt the eventual goal of 200bhp once everything is smoothened out.
@all
There seems to be a real hater mentality around here. It's almost like seeing a rebuild giving someone good performance that would have averted their swap pisses people off. The general consensus with the stock engines seems to be to just swap'em out. In reality it's much easier to do rebuild with performance parts than to spend years on modifying wiring harnesses and creating all the other custom 1-off parts and [typically] years to do a swap.
The only reason I did my original 4.9 swap was because I could pay someone else to do it (Fiero Factory). I'd never waste the amount of time people do on 'swaps' so I appreciate people taking stock equipment and making it work better. I've also seen people spend years on a swap only to complete it and then since it's a non-rebuilt engine, it fails shortly thereafter so not having any more patience it either sits for a long time [again] or gets sold. We do spend lots of time glorifying the few success stories with here though...and then bash rebuilds with like 'bro - when I'm done with my swap in 20 years it will make 4x more power than your 2.8!". Good for you.
Originally posted by lou_dias:and then bash rebuilds with like 'bro - when I'm done with my swap in 20 years it will make 4x more power than your 2.8!".
The only reason I did my original 4.9 swap was because I could pay someone else to do it (Fiero Factory). I'd never waste the amount of time people do on 'swaps' so I appreciate people taking stock equipment and making it work better.
Since you have never apparently done a swap you have no appreciation how easy it is to swap a Quad 4 or even a 4.9L. I've done both. I started with a NOS Quad 4 and a 4.9L from a running car with 30,000 mile on it so they are both RELIABLE cars. I'll bet more time and money was spent on this Iron Duke science experiment that I spent on either of my swaps. I'm not criticizing the people that did the Iron Duke build they had fun doing it. But once is enough.
If you want to play with a N/A 4 cylinder how about a bored out Quad 4 stroked to 2.6L with the 2.4L Twin Cam crank. With 11.0:1 compression that's good for 225 HP. The 086 head on the Quad 4 may be the best flowing heads GM has ever made right out of the box - no porting and polishing required. There is nothing that can be done to an Iron Duke head to make it flow like a Quad 4 head.
------------------ formerly known as sanderson 1984 Quad 4 1886 SE 2.8L 1988 4.9L Cadillac 1988 3800 Supercharged
Originally posted by sanderson231: Since you have never apparently done a swap you have no appreciation how easy it is to swap a Quad 4 or even a 4.9L. I've done both. I started with a NOS Quad 4 and a 4.9L from a running car with 30,000 mile on it so they are both RELIABLE cars. I'll bet more time and money was spent on this Iron Duke science experiment that I spent on either of my swaps. I'm not criticizing the people that did the Iron Duke build they had fun doing it. But once is enough.
If you want to play with a N/A 4 cylinder how about a bored out Quad 4 stroked to 2.6L with the 2.4L Twin Cam crank. With 11.0:1 compression that's good for 225 HP. The 086 head on the Quad 4 may be the best flowing heads GM has ever made right out of the box - no porting and polishing required. There is nothing that can be done to an Iron Duke head to make it flow like a Quad 4 head.
It's not about appreciation but about bashing and trolling. That was the point of my post. If I didn't appreciate swaps, I wouldn't have owned my 4.9/3100->3400/3800SC cars... I just can't be bothered with the process. That doesn't mean I don't appreciate them.
The point of your post was to promote modifying an Iron Duke rather than swapping to an engine with more potential. I you don't believe me go back and re-read what you wrote. Modifying an Iron Duke is just plain wrong.
------------------ formerly known as sanderson 1984 Quad 4 1886 SE 2.8L 1988 4.9L Cadillac 1988 3800 Supercharged
Originally posted by sanderson231: The point of your post was to promote modifying an Iron Duke rather than swapping to an engine with more potential. I you don't believe me go back and re-read what you wrote. Modifying an Iron Duke is just plain wrong.
I think I know my own point. How you interpreted it is up for debate. This is a post about a duke build. Instead - people with swaps come here and bash it. A person doing said build doesn't care about anyone else's swap... Just like a person doing a swap with engine X doesn't care about trolls coming into their thread saying they should have just done a swap with engine Y. Their reasoning is irrelevant. The decision has already been made.
The point of your (Lou's) post was to promote modifying an Iron Duke rather than swapping to an engine with more potential.
I'm surprised/puzzled by this comment. I felt the intent of Lou's post was simply to share an interesting video about an Iron Duke with other PFF members. Has it motivated me to spend big bucks on my '84 duke? Not a chance!
[This message has been edited by Patrick (edited 10-03-2022).]
I'd never waste the amount of time people do on 'swaps' so I appreciate people taking stock equipment and making it work better.
What you said - you didn't come out and say it but you are basically advocating pouring money into an Iron Duke just because it's "stock" equipment.
The people that did the Iron Duke build had a vision and obviously had fun going where no man has gone before. They probably learned a lot that can be applied to other projects. It's been done once. Why repeat it? I have a vision of building the ultimate N/A Quad 4. I want to do it just because I haven't seen one done before. Is it worth the time and money versus just a rebuilt Quad 4 HO. A lot of people would say no. I'm fine with that. ------------------ formerly known as sanderson 1984 Quad 4 1886 SE 2.8L 1988 4.9L Cadillac 1988 3800 Supercharged
[This message has been edited by sanderson231 (edited 10-03-2022).]
What you said - you didn't come out and say it but you are basically advocating pouring money into an Iron Duke just because it's "stock" equipment.
The people that did the Iron Duke build had a vision and obviously had fun going where no man has gone before. They probably learned a lot that can be applied to other projects. It's been done once. Why repeat it? I have a vision of building the ultimate N/A Quad 4. I want to do it just because I haven't seen one done before. Is it worth the time and money versus just a rebuilt Quad 4 HO. A lot of people would say no. I'm fine with that.
Well, at least you are admitting in putting words in my mouth. I've done 2 6-speed swaps. Have you seen me post any getrag rebuilds?
[This message has been edited by lou_dias (edited 10-05-2022).]
Originally posted by sanderson231: ... Modifying an Iron Duke is just plain wrong.
I wouldn't say that. One of the guys in our club has modded his. (S10 head, moderately lumpy cam.) It's maybe 120-130 HP. It's certainly not going to rip anyone's face off, but he has a lot of fun with it, and is quite satisfied. Only spent a few hundred dollars above the cost of a stock rebuild, which it was getting, anyway. I've thought about (just for the hell of it) bolting an early, cast iron SD head onto an 87 bottom end (has a stronger crank, but will eliminate the unobtainium force balancer), along with a lumpy cam and a larger (maybe a 4.3 or 305?) TBI. Would it run? Most likely. Would it run well? Probably, after some tweaking. Would it blow up? Maybe. But it would be hellishly fun while it lasted. And would certainly surprise people, since it could be built to look nearly stock. Is it financially foolish? Absolutely. But we already drive Fieros, so there is a precedent.
Jeez, y'all. Lighten up a bit. It's a hobby. We don't all have to do it the same way.
[This message has been edited by Raydar (edited 10-05-2022).]
I wouldn't say that. One of the guys in our club has modded his. (S10 head, moderately lumpy cam.) It's maybe 120-130 HP. It's certainly not going to rip anyone's face off, but he has a lot of fun with it, and is quite satisfied. Only spent a few hundred dollars above the cost of a stock rebuild, which it was getting, anyway. I've thought about (just for the hell of it) bolting an early, cast iron SD head onto an 87 bottom end (has a stronger crank, but will eliminate the unobtainium force balancer), along with a lumpy cam and a larger (maybe a 4.3 or 305?) TBI. Would it run? Most likely. Would it run well? Probably, after some tweaking. Would it blow up? Maybe. But it would be hellishly fun while it lasted. And would certainly surprise people, since it could be built to look nearly stock. Is it financially foolish? Absolutely. But we already drive Fieros, so there is a precedent.
Jeez, y'all. Lighten up a bit. It's a hobby. We don't all have to do it the same way.
I'm fairly certain the 4.3 and 5.0 and 5.7 TBI units are identical with the exception of the injectors. you'll probably need an EBL or other ECU to actually use it, I'd bet the stock duke ecu doesn't have two injector drivers. super duty parts are cool, but as already noted in this thread, the duke engine block isn't all that stout, the castings are pretty thin, which tends to mean they also aren't very rigid, which usually leads to cracks under stress. I'm kinda curious what a dyno of a 3.0l ecotec would look like, personally, I wouldn't particularly want to build either, but each has some merits, the built duke would still bolt in the stock mounts, the ecotec would almost certainly be lighter.
------------------ "I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."
I invited Lou Dias to trash me in my own thread, he refused. sorry. if he trashes your thread going after me. I tried.
I'm fairly certain the 4.3 and 5.0 and 5.7 TBI units are identical with the exception of the injectors. you'll probably need an EBL or other ECU to actually use it, I'd bet the stock duke ecu doesn't have two injector drivers. super duty parts are cool, but as already noted in this thread, the duke engine block isn't all that stout, the castings are pretty thin, which tends to mean they also aren't very rigid, which usually leads to cracks under stress. I'm kinda curious what a dyno of a 3.0l ecotec would look like, personally, I wouldn't particularly want to build either, but each has some merits, the built duke would still bolt in the stock mounts, the ecotec would almost certainly be lighter.
I think the Ecotec is absolutely at its displacement limits with GM's current 2.5 version. The L3B 2.7 4 cyl in the trucks (and now Cadillacs?) might be able to go to 3.0, but it's pretty darn new.
I have been commenting with RacerD on youtube, who should be the engine builder. the Flow data for his ported S10 head has been uploaded:
S10 Duke Head
Lift Stock 1.72 E Ported 1.97 Ported E
0.1 46.3 46.6 63.9 65.9
0.2 89.9 86.3 127.8 112.1
0.3 111.2 125.3 166.7 141.7
0.4 121.3 145.3 189.9 156.6
0.5 127.2 192.1
His Camshaft:
quote
244 251@.050. 303 311 adv, with .570 intake lift and .580 ex. on a 114 LSA installed at 106 In C/L
quote
The port volume is only 166cc, the major problem is in the bowl around the valve guide, and you cannot fix it w/o hitting water. Changing to the SD head would be a problem for my headers, because the D shape Ex port s very small also. If I get time this winter I want to build a new dual throttle body intake and get the Port Injection up and running again.
I have an SD4 head casting 10031323: Test Pressure inH2O 28 Lift In Intake CFM Exhuast CFM W/ 2BBL Manifold Intake Valve Dia in 2.02 0.05 38 26 36 Exhuast Valve Dia in 1.63 0.10 63 53 51 Throat Diameter in 1.82 0.15 85 75 87 E Throat Diamter in 1.46 0.20 116 105 118 Intake Volume cc 180 0.25 137 119 137 Exhuast Volume cc 74 0.30 160 130 156 Chamber Volume cc 55 0.35 178 140 173 I Gasket CSA sqin 3.42 0.40 194 149 188 I Pinch CSA sqin 2.26 0.45 215 156 200 I Throat CSA sqin 2.36 0.50 229 163 209 Valve Stem Size in 0.313 0.55 237 168 220 E Gasket CSA sqin 1.5 0.60 248 171 230 E Pinch CSA sqin 1.25 0.65 236 174 E Throat CSA sqin 1.81 0.70 235 176 I Port Length in 4.25 0.75 237 178 E Port Length in 3.13 0.80 240 179
With a 4.06" bore block and a marine 3.5" stroke crank, I think the head he made is sized ok for a street motor up to 6000RPM. Running an iron SD4 head, with its 180cc would be raising the potential RPM for peak power from 6000 to 7000, provided it has the cam. Which, the lift on his cam can take advantage of the larger port and peak flow, but I don't agree with his LSA selection nearly as much, but he has much more experience in engine building than me. But from what I think, his flatter torque curve gave up some peak power and cut the power production early, I think would need to narrow the 114 closer to 109 or 110 with the SD4 head on a duke running a 2 barrel carburetor.
I have no doubts his crankshaft added quite a bit of strength to the duke, its just a matter if the block can live eating all the torsional excitations from that big of a 4 cylinder, and I would probably try to keep the engine from making its peaks past the 6500RPM speeds to play it safe. If anything he may be giving up some ring seal, and a few HP across the range, but I don't think his block will blow up quickly. People raced these motors in boats and in sprint cars and not all of them used Super Duty blocks.
I felt the intent of Lou's post was simply to share an interesting video about an Iron Duke with other PFF members. Has it motivated me to spend big bucks on my '84 duke? Not a chance! 
multiple times.
