Iron duke 172 bhp / 220 ft*lbs! (Page 1/5)
lou_dias SEP 09, 09:11 AM


Apologies if this has already been posted. Impressive but probably hard to reproduce given all the custom parts!
Dennis LaGrua SEP 11, 07:33 PM
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. .

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" 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 "

Will SEP 12, 09:35 AM
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.
lou_dias SEP 13, 01:23 PM
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...
Will SEP 14, 09:50 AM

quote
Originally posted by lou_dias:

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.
Dennis LaGrua SEP 14, 12:23 PM

quote
Originally posted by Will:


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 "

lou_dias SEP 14, 06:10 PM

quote
Originally posted by Will:


Not what I meant.
The production block--the casting itself--is not up to making decent power for any reasonable service life.



???
If your bottom end uses quality parts there is less odds of throwing a rod...etc... Perhaps you mean "the production bottom end"...
Slammed SEP 15, 03:55 AM
A 200hp Duke is not a hard build. The block is fine.

https://www.summitracing.co...a-2600020-1/overview
https://www.summitracing.co...8723ws-4030/overview
Mercruiser 3.0 crank with the one piece flange like this:
https://www.ebay.com/itm/11...&campaignid=16743749 222&mkgroupid=138744546207&rlsatarget=pla-1644837434363&abcId=9300842&merchantid=427104207&gclid=Cj0KCQjwmouZBhDSARIsALYcouoFzwX1s2cwzO9u0dznOMgaWRAA50i4NrgdNCIWrFNPhaYOCoSK4_kaAlC-EALw_wcB

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.
Dennis LaGrua SEP 15, 12:37 PM

quote
Originally posted by Slammed:

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).]

Will SEP 15, 09:38 PM

quote
Originally posted by lou_dias:

???
If your bottom end uses quality parts there is less odds of throwing a rod...etc... Perhaps you mean "the production bottom end"...



The block cracks, dude.
As demonstrated by...


quote
Originally posted by Slammed:

Half fill the block.