I have a thread going about headwork on this S10 I'm building for a guy but it is going in a different direction so I'm starting a new one
'89 S10 motor
Update: New head! Mucho work done. 9.5 secon 0-60! This is an automatic. Huge jump in power
I enlarged the ports 8.5mm vertically and 3mm in both the intake and head. Stock 1.72 valves. The throats have been enlarged to 1.54" The throat is actually bigger than the 3800SC heads I have sitting here.
But, this is where things have gone past head work. We just received the forged rods and pistons. 6" 2.00 rods and +5cc 1.565 comp height pistons. This is a very low mileage motor and will keep the standard 4" bore. Should give us just about 10:1 ratio
Headwork
Ideas, thoughts, and comments all welcome.
[This message has been edited by Slammed (edited 06-18-2015).]
Interesting. I've got an SD4 that I'm about to bolt the 2V version of that manifold onto. (Removed the Dellortos to give them a proper rebuild. Am installing a 2V Holley to make the car driveable while I screw with the others.) The ports in the head are already huge. I may match port the intake if it needs it.
Would have been nice to start with an SD4. AFAIK the S10 motor hasn't been built like this before so it'll be interesting to see what happens
The rods/pistons were bought in sets of 8. If he blows it, we'll just do another and throw this head on it with a thicker gasket. We are going with a custom copper HG at .010 right now
We started over with another head. I put hardened seats in the exhaust and installed new guides
Wow. I don't know how else to explain it. The difference is night and day. The only comparison I can make is to my '84 4 speed that was rebuilt last year
This is an automatic S10 and it laughs at my little Fiero. Mind you, this is on a stock tune, stock throttle body, factory cam, with the original (clogged) cat from 1989. Also, this is a tired bottom end. Compression is only 150 and the ridge on the cylinder walls would need at least .030 to remove it. It pulls right to 5000
We will dyno it after the tune, TB bore, cam and exhaust.
[This message has been edited by Slammed (edited 06-08-2015).]
Have burned a couple chips now and driven it a couple hundred miles
Most dukes idle sort of rough and vibrate. We haven't installed a harmonic damper and the engine is sooo smooth. Sitting at 750rpm you can barely tell it's running. So little vibration. I've never seen headwork make such a huge difference on a vehicle. The power comes on immediately and turns right up to 5k no problem. Merging is a breeze and cruising at 75 uphill is no problem.
What fuel supply are you using? Is it carbed or injected? If injected then what TBI - the standard Rochester 300 or the newer 700? Any mods done to the fuel supply system?
Interesting project and nice work. The last modified Duke that I recall was built about 12 years back by Neil and Dawn Kline (Racincouple) . Neils health issues caused the sale of the car and someone else in PA owns it now. It had a cam and SBC 10:1 pistons. The engine ran well provided extra power and for the time that they had it stayed together. I estimate that if your goal is 125 HP, the S10 block and crank should suffice.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Flotech Afterburner Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, 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 "
Cool man, wish you luck. Dukes are cool engines, simple, reliable, economical - a shame people hate them for their lack of power and their noise. Seems the power issues are solved! Did you calculate fuel consumption? Is the auto the stock THM-125C 3-speed?
EDIT: Just read that it's an S10 not a Fiero... what auto gearbox do you have though?
[This message has been edited by cebix (edited 06-13-2015).]
We are past 125 already I'm sure of that. We'll be north of 160 before we are done with it. To compare, the 2.8 auto Fiero is a 9 second 0-60.
That is before the Eaton M62 goes on.
Those horsepower numbers are very impressive but I would suggest being very cautious putting boost in that engine. The Duke doesn't have the best record for reliability with boost. Thin block walls and lightweight connecting rods are a limitation. I know of one Duke "Hi-Tech" turbo install formerly owned by Steve V (BV Motorsports) and it did work but IIRC the boost was kept to 4-5 psi. Estimated Horsepower was about 135. AFAIK, the car has changed hands twice after Steve had it and still exists.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Flotech Afterburner Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, 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 "
We have another motor being built right now. Forged rods and pistons with a cryogenically treated crankshaft, and a 1pc 3.0 rotating assembly as backup. In '98 we had a turbo duke in a buggy pushing 140 to the wheels. Stock internals and we beat the absolute crap out of that thing
For how many years now has everyone been talking about weak duke, this that, with how many pictures of actual failures of motors built by reputable builders? To give you an idea, I have bored several iron dukes to .060 with no cylinder failures. The whole thing is blown way out of proportion. Add to that, out of the dozens of dukes we have had in the machine shop over the years, the most common thing is rods. I have never once seen a broken crank. Now, most of the people aren't out hotrodding these anyway, but it's something to point out
[This message has been edited by Slammed (edited 06-14-2015).]
I've never seen headwork make such a huge difference on a vehicle. The power comes on immediately and turns right up to 5k no problem. Merging is a breeze and cruising at 75 uphill is no problem.
quote
Originally posted by Slammed:
... out of the dozens of dukes we have had in the machine shop over the years, the most common thing is rods. I have never once seen a broken crank. Now, most of the people aren't out hotrodding these anyway, but it's something to point out.
Vanderley developed the head for the Pace Car/Super Duty engine. According to the SD4 Guide, the head flows 80% more air out of the box (before any porting or other head work) than the stock Duke head.
It is common knowledge that the Duke engine fires were caused primarily by failing connecting rods. They were crap pieces to start with and once the engine ran low on oil and seized, they would break.
The better flowing head will make the power, and aftermarket rods will keep it from breaking. The Duke crank will have a limit on horsepower and RPM it can handle (SD4 crank RPM limit is 9,000)
Looking forward to the final configuration dyno numbers. It's neat to try new ways to make power, but I have to wonder how much it's going to cost to approach the power of a stock 3400 or 3800NA.
Looking forward to the final configuration dyno numbers. It's neat to try new ways to make power, but I have to wonder how much it's going to cost to approach the power of a stock 3400 or 3800NA.
The OP plans to add boost so we will have an opportunity to see if he is able to go beyond the power limitations of the Duke engine. My guess is 135HP at the flywheel and 100HP at the wheels is possible. . That would give the car 2.8L performance.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Flotech Afterburner Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, 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 you both missed this is a customer car with an unlimited budget. 200bhp is the goal. Not done until we hit it
We have two motors that we are putting together right now. Both .030 over, 6.000" Eagle SIR I beams, Keith Black +5cc 1.565ch pistons and arp hardware. One is a stock nitrided and then cryo'd crank, all balanced. The other same internals, except 5.7 not 6.0 rods, but a 1 piece 3.0 crank, turned to 2.00 . Again nitrided and cryotreated. 135hp? Ha.
I posted it above, but I raced a buggy in 98 and 99 with a bone stock, new 93 turbo duke. 140whp and we beat the heck out of it
[This message has been edited by Slammed (edited 07-05-2015).]
