[Alsfarms]

Thanks to the internet, I have learned about big end widths, why perfromance rods are thinner and how to accomodate a thinner/lighter rod. That said, I have located a set of 6.200 SBC small journal rods for my S-10 stroker. I will be turning the stock marine crank down to fit the rods. I will be looking to see what piston/comp. height I can locate, before I do the crank work.
Regards, Alan

 

[Alsfarms]

Question for the day.....
What is the deck height on a stock S-10 block? How much shaving can be done safely on the block before you hit water? Same question for the head?
Thanks,
Alan

 

[StrokerS10]

Thanks to the internet, I have learned about big end widths, why perfromance rods are thinner and how to accomodate a thinner/lighter rod. That said, I have located a set of 6.200 SBC small journal rods for my S-10 stroker. I will be turning the stock marine crank down to fit the rods. I will be looking to see what piston/comp. height I can locate, before I do the crank work.
Regards, Alan

Alan,
Now you are on the right track....... well maybe!?

Since it sounds like you are still going to use the 1.035 width rod journal crank you must be planning to use "Piston Guided" rods? You can go that route if you want, and yes it will work, But before I would do that I would try and find the "Really Late" marine crank that is "supposed" to accept stock width SBC rods and start there. Also are the 6.2" rods that you have located designed to accept the std. .927" wrist pin? If not you will end up spending "Big Bucks" on custom pistons. Many if not most of the 6.2" used "Nascar" rods on Ebay are designed for the .866" or other "odd" sized wrist pins...... beware! But remember though you will be spending a lot of money on the special machine work required to fit that crank into the Duke block and to accept the Duke flywheel. And when all is said and done are you going to trust it??????

Read post #63 again for a little more rod length vs stroke info.

The Duke has a deck hieght of 9.175"+ or -. Don't deck it more than absolutely necessary as it is very thin to start with and make sure the machine shop uses a torque plate when they bore and hone it to maintain cylinder wall concentricity. Very important with the Duke block.

Included are some photo's of my 3.42" SD4 crankshaft/pistons/rods for my Duke block. I just picked up the parts from the machine shop yesterday. It is a true SD4 crankshaft stroked (from a 3.25" version) to 3.42". It is ground to accept a std. 1.889" (Quad four/Nascar) journal rod bearing. The rods are 6.2" Carrillo's (SBC width) and the pistons are Keith Black .030 over Hypereutectic.

Now to make you really drool;
I have, still in the GM crate, a brand new 3.625" stroke SD4 crankshaft. After selling all of my SD4 stuff last year I saved it as I was not sure at the time which crankshaft I was going to use for my "Last" Duke stroker engine. I chose to use the 3.25" crank and upstroke it to the 3.42" rather than destroking the 3.625" crankshaft. When I finish the engine I am building now I will sell the 3.625" crank to the highest bidder on Ebay. The bidding will start at $800 unless someone makes me an offer....... that I can't refuse!

 

[StrokerS10]

StrokerS10: Well I dropped off my 437 head at the engine builders the other day to get some flow numbers. We discussed the middle and late mercruiser cranks. And came to the conclusion that the later model would be the best even though it's more expensive. Would have a wider selection of rods (SBC) and possibly stronger. The middle crank would require custom rods and cost more than the late crank. We also discussed the CR , 9-1 would work with 91 octane keeping the boost under 10 lbs and boost to 15 lbs on race gas. The 437 head had 2.125" intake valves, isn't that big block size? It was also port ,polished to the extreme of getting into the pushrod area which they epoxied, previous owned=they. We will get that fixed for road durability. Am I on the right track? Any suggestions?

I would not run a compression ratio higher than 9-1 and in fact if it were me I would probably run 8-1 or less. It would be a safer route to go and you could then run more boost. 9-1 will work though as I have built one 3.25" Duke with 9-1 C/R and a T3/T4 Turbo. Afterwards I felt the straight T3 or maybe even the T.28 might have been a little better choice for this engine as it would have spooled quicker. I never got the chance to test a smaller turbo though. You are running a larger C.I. engine so probably the T3 or T3/T4 might be best for your application. If I were you though I would contact Garrett for turbo sizing advice before I went any furher.

So you are shooting for 400 hp or so, right? When you are in that HP range a cast (marine) crankshaft is probably at or near it's limit. In that range (or higher) I wouldn't recommend anything less than a forged (SD4) crankshaft. If you can afford to experiment, go for it. If it were me though I would play it safe and go with the forged crank. Besides once you buy a marine crankshaft you will need to spend a bunch of money on it at the machine shop just to make it fit the block and the flywheel. Then spend more to magnaflux and turn the journals and you will have maybe $500 - $600 or more in it, wouldn't you rather spend the extra money and have an SD4 crank? One that is forged and one that you can trust?

I know that it sounds like I am trying to sell you a crankshaft, believe that if you want, but everything that I have said here is the truth. Besides I will have no problem selling this SD4 crank as there are far more people wanting them than there are SD4 crankshafts for sale.

Good luck with whatever route you take! Your going to need it and a lot of patience as well...... Been There, Done That! lol

 

[Mystyk_Wynds]

Hey stroker,

I do have some interesting concepts I would love to discuss with you. This mainly to see the feasibility of it in your eyes. I wan't to keep this under the radar until I know it works or doesn't and then let the cat outta the bag so to speak.
Hit me up in my email so I know your interested.

 

[Mad Max]

Do these look familiar? Anyone need one?

 

[Lilchief]

I got my head back from the engine shop and got some good numbers. I posted the flow sheet on another forum and here's the link.

http://www.fiero.nl/forum/Forum1/HTML/084256.html

 

[Hyphynator]

@mad max
How much?

 

[Desert Toad]

I do not usually post on the net but you guys have a lot of answers regarding the Pontiac 151 Iron Duke.
I toasted my Pinto 2.0 engine in my 5 seater sand rail and was looking for a inexpensive replacement.
I was leaning towards the Chevy II 153 Stove bolt but, when I was doing some research I found the Marine 181/3.0.
I was almost set when a speed shop told me that I should look into the Pontiac 151 Iron Duke. That's when when I came across this Thread which is very informative.
I am on a budget so my plans was to get a running engine and re-ring it, install a cam for 2500 to 5500 rpm, intake and of course headers.
My question is the 151 really better than the 181 for my application. I do not want to do a lot of machine work, maybe some head porting which I would perform.
It is not my intention to hijack this thread but I feel that my question would be answered honestly.

 

[Steady Eddie]

I do not usually post on the net but you guys have a lot of answers regarding the Pontiac 151 Iron Duke.
I toasted my Pinto 2.0 engine in my 5 seater sand rail and was looking for a inexpensive replacement.
I was leaning towards the Chevy II 153 Stove bolt but, when I was doing some research I found the Marine 181/3.0.
I was almost set when a speed shop told me that I should look into the Pontiac 151 Iron Duke. That's when when I came across this Thread which is very informative.
I am on a budget so my plans was to get a running engine and re-ring it, install a cam for 2500 to 5500 rpm, intake and of course headers.
My question is the 151 really better than the 181 for my application. I do not want to do a lot of machine work, maybe some head porting which I would perform.
It is not my intention to hijack this thread but I feel that my question would be answered honestly.

====

DT--

Welcome to the Forum....I have a 4 seater myself..
a 2110 cc. VW-based rig.

If I were you. I'd go with another Pinto motor.

The Iron Duke has a strange transmission bell housing with no aftermarket adapters available.. and, it is down on power, too. There are many 200 to 300 HP Turbo Pinto motors out there and I have seen and duned with a few. At the RPMs that a Pinto will run, an Iron Duke will flat destroy itself.

All that said, a Super Duty Iron Duke WILL pull to about 9000 RPMs and live. But they are very spendy and hard to find.

Again, WELCOME....

 

[Mystyk_Wynds]

Ladies and gentlemen. I have found out that putting a sbc head on a duke, is damn near outta the question. Soooooooo many differences bolt holes coolant passages have to welded up and rerouted. Talk about insane.

So does anyone have an SD Head and or an SD Crank for sale?

 

[Mystyk_Wynds]

I agree with steddy eddie on this.. Your looking at spending a good fortune on building a duke. Ironic a 181 would suffice, should you find someone that can acceptably adapt a trans to it????
Sd block $3400-$4k, custom forged crank $1800-$3k, camshaft $400+...Sd head, SD crank acceptable intake..Good luck.

 

[lesterl]

Why could you not use a trans and engine out of a FWD car? Then you could have independent rear suspension and the transmission would match, for that matter the trans off a 3.4l/ 3.8l should mate, right?

 

[Mystyk_Wynds]

Well I thought I would inform you gentlemen that read this. After even more in depth research, I should let you all know a very significant detail.
It seems that the duke as far as Rocker Arms, is actually equipped with 1.75. So those that are changing to 1.7 or 1.6 are in fact reducing the valve lift.
Also the stock rockers are in fact stamped steel, so they are quite durable. So if your building a mild street engine, then 1.6 full rollers, dont equate to as much to gains as what the lift of the stock rockers are in comparison.
IE. in theory say you have a 455 lift. with a stock rocker its .796 with a 1.6 its 728 and a 1.7 its 773. so you can see how down sizing the rocker arms can hurt. But on the ohter note, this may have to be done in order to avoid ptv clearance isssues.

 

[Wildbill0088]

Awesome thread will have to read the whole thing when I have time. I just picked up a 1983 Am General DJ5 mail jeep with the Iron Duke in it, is there anything strange about this motor that I should know? I have an 83 S10 longbox with an empty engine bay and i'd like to know what it would take to put the duke in it with a 700R4.

 

[Mystyk_Wynds]

Awesome thread will have to read the whole thing when I have time. I just picked up a 1983 Am General DJ5 mail jeep with the Iron Duke in it, is there anything strange about this motor that I should know? I have an 83 S10 longbox with an empty engine bay and i'd like to know what it would take to put the duke in it with a 700R4.

Ok to answer that question simply is No. The 700r4 is a sbc bellhousing pattern, where as "MOST" dukes have a 2.5/2.8 pattern.
Second you must understand that most dukes only put out 90hp. The 700r4 is best used when you push at least 150-200hp. Since that is the average hp of the engines they put them in.
My suggestion is this, If going with an auto, either get the trans out of 2.8l or go with a 200r4(MUCH better 2nd gear ratio). Now the fact that you have an 83 motor, you may be lucky enough to have a block with the sbc pattern.
As far as strange, if you don't have literally thousands to sink into a duke, don't be hell bent on performance, cause its just not gonna happen.

 

[lesterl]

700r4 came with a 60*/ duke compatible bellhousing, what do you think they put behind the 2.8l?

 

[Wildbill0088]

After more research on the mail jeep everything I find says it has a sbc bellhousing bolt pattern and a chrysler 903 transmission with a sbc bolt pattern which would explain why I could not figure out what trans I was looking at. This goal of this truck is to be an economic runabout so i'm not always driving a fullsize 350 powered blazer around. My only concerns at this point are motor mounts, flywheel compatibility and the trans kickdown cable.

 

[Wildbill0088]

Oh and I have seen a 250 I6 rated at 100 HP hooked to a 700R4 in a C10 so I don't believe I have a big issue there.

 

[twallaw]

have 87 fiero with 2.5L Iron Duke Vin R...thinking about swapping with 93 Vin A from S10...what are the differences I need to consider?

Starter? Bellhousing?

Any help...greatly appreciated.