Iron Duke race motor???

mlburgoon · Post by **mlburgoon** » Wed Jun 06, 2007 3:59 pm

is the 4-cyl pontiac (gm) iron duke motor a possibility to make a race motor out of. This would be the NON-SD motor. just the regular production block and crank. I can put in any pistons and rods I want to.

I am wanting to build a 3rd gen camaro as a ministock to race the old 80's style mustangs that are in the class. But I would have to use the old iron duke\tech-4 motor.

what are the issues I will run into and how much HP can I make with it?

thanks

PackardV8 · Post by **PackardV8** » Wed Jun 06, 2007 4:55 pm

Greetings, mlburgoon,

If no one at your track is doing it, there is 99% of your answer. Very few racers/racetracks leave much money on the table. Winners run what won.

thnx,jv.

needforspeed66gt · Post by **needforspeed66gt** » Wed Jun 06, 2007 5:05 pm

I know a machinist who used to build those for racing applications a long time ago, I will ask him what the deal is.

user-9274568 · Post by **user-9274568** » Wed Jun 06, 2007 5:35 pm

Call KRP, Kansas Racing Products, they own the molds. They will answer your questions.

jacksoni · Post by **jacksoni** » Wed Jun 06, 2007 5:45 pm

It is my understanding that the stock block and crank are major weak points limiting RPM and therefore HP potential. The basic configuration can be built to good HP levels and with the SD head make serious power. There are a lot of this basic engine in many configurations in ARCA trucks (at least have been) drag cars in Comp Elim and midgets but all use either the SD block or KRP. 400hp+ in drag form is not unusual with 165-180 ci. Chad Speier (cspeir) on this board has built one for drags( but so far as I know is not running yet) and I have one for Bonneville( in an '86 Firebird) but all aftermarket stuff and $$$$$. I'd suggest go check out some of the fiero boards and websites as they tend to deal with stock build up more and I have seen, but can't at this instance lay my hands on, some sites dealing specifically with hot rodding them. There is also the old Pontiac book on hotrodding them that is no longer available(occasioally comes up on Ebay) but deals with the SD block. I have a print out but not the online source of this- (some guy scanned it and sent to me but I can't get it onto this computer so I could send to you.) (If you can't find and really want, may be able to print it out and mail to you) . Also, HOT ROD did an article about hot rodding them a number of years ago. If you want I'll try to find it. Have a copy floating around here somewhere.
It does, of course, bolt in to 82-92 Camaro/Firebird as you know and was available up to '86 I think.

Jack

Woops, Chad beat me to it. You got it running yet Chad. I saw you asking about that head bolt wrench. I found one on Ebay for a lot less than the $27 snap on wants.

user-9274568 · Post by **user-9274568** » Wed Jun 06, 2007 6:47 pm

I ordered a Proto!! $17.00 shipped

Actually I ran into a nightmare. I also got a head from Darin, Reher-Morrison. I sent him a core, they CNC'd it. He sent it back and I had seats/guides installed. Then one weekend I drove to RM and Darin and I finished it. Well, I get it home and was ready to put it on the block. The holes were drilled wrong

The center row was close to .300 off. I had to take all them out to .500 to get them to fit over the studs. Then I had other issues, insert/seat washers, etc.. It's been a LONG project. It's finally together, going to dyno it soon..

The book your after is Pontiac Performance Plus. It has some nice info on this engine. I found mine on ebay, where else??

rmcomprandy · Post by **rmcomprandy** » Wed Jun 06, 2007 9:48 pm

In the 80's Pontiac used to sell 2.7 liter steel, stroker cranks for them and had two, (if not more), high flow, aluminum cylinder heads with both production and wider intake port spacing. The early rear wheel drive blocks had quite a bit of meat in them.
Some of those parts must be somewhere...???

JBV-HEADS · Post by **JBV-HEADS** » Thu Jun 07, 2007 4:25 am

The SD can be made to run very well. It’s the OEM rules that kill them. KRP, Fontana and Ed Pink all make parts for them. They just aren’t legal except in USSAC and Arca stuff. If you must run OEM head then you’re about dead in the modified arena. Next the bottom end will get you as described. For twice the money you can make it work in the Super 4 classes that use OEM top and bottom. But if the class allows roller cams, the Fords will eat you on power. I love the bore and stroke combo. And they can be made to fly. But rules kill them. Unless you shoot for the top with the above blocks and rotating assemblies. Add a Yates head or something similar. You’ll be pushing a very big, expensive rock up a hill. With the group here, anything can be built. It’s just cost and is it worth it. But if you want to run GM and it must be 2 valve. The Pontiac is the best choice. Love that bore and stroke. Half a 302 but man a 502 is cheaper to build. Good luck,

Joe

jak · Post by **jak** » Thu Jun 07, 2007 6:57 am

Chad, I was looking at the KRP block to build a 4 cyl turbo motor.
I have SBC dart buick heads cnc ported by M2 and Slawko and 2 sets of 12 degree rollovers done by Rons.
Would this block take these heads and then if they did would it be able to handle the boost.
I was doing research on this and realize that no-one has done it (if they have I havent seen it) Is there a good reason for this or has no-one thought of it.
I think that if it could work it would give every other 4 cyl turbo engine out there a run for there money.
What do you or anyone else for that matter think of this idea and does anyone have some more background on it ,I would be very interested to hear their thoughts.

jacksoni · Post by **jacksoni** » Thu Jun 07, 2007 9:29 am

Chads and my engines both use a SB2.2 head. The KRP block can be drilled for pretty much anything- SBC, Ford or Mopar heads and I have seen GM splay-valve head on one. 430hp+ at 10200 through the traps Comp engine. Most of the high power 4 cyl stuff we see these days seems to be foreign car 4cyls and the Ecotech ( I see and follow pretty much only Salt racing stuff but I know you know there are lots of drag stuff out there. Several Ecotechs with GM and SoCal Speed shop support running 170+NA to 230+Blown in a Cobalt and HHR and 325+ in liner -Ron Main ). There is a Barracuda at the salt running way over 250 with 4 cyl Mopar power and they are looking for 300. Check this link.( or google blowfish bonneville for bunch of sites)

http://www.hotrod.com/featuredvehicles/ ... ngine.html

The KRP block with appropriate components I think is considered fairly equivalent to the above (likely to get an argument about that- I only know what I have read

). My engine recently made an unexpected excursion to neighborhood of 14000 rpm and all I hurt was the valve springs.

Go for it!

mlburgoon · Post by **mlburgoon** » Thu Jun 07, 2007 9:34 am

well, I just read through the rules again. I am going to verify what I think I can do with the tech guys at the track.

But I can use any crank I want to. I know from a previous talk with them I have to use an OEM PRODUCTION block. an OEM head (does not have to be production, just an OEM head). I am limited to 2550CC. so i could get a crank from KRP with a 3" strock and bore the block .060" over which would give me 2545cc. Also limited by using a holley 350 carb.

like to rules: http://www.i70speedway.net/2007-2008_Dash_Rules.pdf

In theory I could use a stock block (strongest I can find from reading is from an 88 s-10), KRP crank, a GM fastburn v-8 head!!! Custom headers are alowed.

I must run an OEM intake, but I think there are some good ones out there. I can modify the intake, but it must be an OEM one. I just don't know if I can modify one to work with a GM v-8 head. It sucks because all of the motors that run out there have to fall into this rule except the ford 2300 motors and they can run the esslinger intake. Only motor that gets to use an aftermartket intake. I may push for a rule change on that.

thoughts?

user-9274568 · Post by **user-9274568** » Thu Jun 07, 2007 9:43 am

Everything Jack said..

The only few issues I have are bore size. I have mine at 4.165 at trust me that's pushing it! The block is filled. They also are a 1/2 main stud. However, Pro-Gram makes splayed caps for it.

The only turbo 4 cylinder I know of is a Ecotec.

My engine is a 202 cid. I fully expecting 480-500 hp. I've also know a guy who had a Buick head on a KRP block. Most of the older Fareman stuff was Buick. I do know the fastest guy in my class has a KRP block and a CFE wedge head. He just set the record. I'm also using a dominator and he has webers. But, he owns a converter company, wonder if that helps

jacksoni · Post by **jacksoni** » Thu Jun 07, 2007 9:59 am

The head bolt pattern in a stock Iron Duke is different than the SBC so you would need to use the stock or SD head (several available) Some of these flow quite well and should be sufficient for what you are doing if legal. (modified up to 270cfm intake, 150+exhaust) GM does still show a 4bbl intake for the SD( not high port) head in the performance parts catalog (pn 10038470).

I think I read that there is a Marine Crank (these engines are in a lot of boats (I have one) that is pretty decent ( but I think longer stroke for a 3 liter so may not fit your needs) and KRP does supply/make a nodular iron crank as well.

user-9274568 · Post by **user-9274568** » Thu Jun 07, 2007 10:25 am

Jack, have a question.

Did you get a plate made for the Jesel stuff? Or did you go with a timing gear? Anyway my question, did you plug off the oil gallery hole? Or did you restrict it with a small oil feed hole? I just used a solid plug, no feed hole. I asked, and was told it can be done either way. Just curious on how you did it. The plate is machined with an oil groove, but appears splash isn't an issue.

rmcomprandy · Post by **rmcomprandy** » Thu Jun 07, 2007 10:30 am

That Pontiac 4 barrel manifold can be made to fit a High Port aluminum SD cylinder head by redrilling the intake flange bolt pattern and moving the center ports a little with some welding if that is legal.
According to the old Pontiac literature, that high port head is only about 5% to 7% better, (about 300 cfm of airflow at .700" on the intake side), when both are fully ported.

Way back when, (in the late 80's), we even used two of those heads on top of a 400" olds V8.