Someone asked about the oiling system. I bought the high volume oil pump and shimmed the relief valve with a couple of washers to boost the pressure in the system. The stock oil pan was enlarged it now holds 6L of Premium grade Castrol GTX 10W30 and a windage tray was also installed. I definitely recommend the enlarged oil pan and high volume pump the last thing you want is for anything to starve for oil. I believe Holley performance sells the TEC II system although to date I haven't located one at a reasonable price. Someone also asked abut emissions testing. This motor will pass if it is running in closed loop at base startup open loop operation it tends to be a little bit richer than it should be. Unfortunately this is a nescessary evil and is caused by the increased fuel pressure at the TBI. The increase in pressure is nescessary to achieve the higher RPM as the stock system tended to run out of fuel around 5800 resulting in an extreme drop in power. If I think of anything else I'll add it to this thread. Feel free to ask more questions or state your opinions I'm always open to feedback and Am interested to know if anyone else has any Ideas to get even more power from the Duke.
Now as for your set up id really like to see it in person, so where the heck is bently anyways? Ive lived in alberta my whole life and even checked my atlas and i cant find bently...
Any chance of driving it to calgary, or possibly reddeer on my the may 12, several calgary and edmonton owners will be there.
Technician, have you thought about using a Mega Squirt http://www.bgsoflex.com/megasquirt.html they are less than $200 and it seems like it would work good with your engine. Also, superchips.com will custom program your stock computer for like $250.
It seems to me that this would be a perfect set-up for the fuel computer that everyone was talking about in another thread. The website is under construction but its http://www.dynotuner.net
I have an '88 5-speed coupe that I'm planning on rebuilding/modifing. How many of these mods are applicable to post-'87 tech 4s? I already know that the Holly aftermarket TBI and intake runners will NOT bolt up to these engines sans physical modifications (read; mounting plates). Any thoughts as to a PFI system for the Duke? Can I get by with the block from the '88 Fiero, instead of sourcing the S-10 block? Will I need to modify/replace the DIS, or can it be used as is? I'll ask more when I think of some more questions. Thanks.
Originally posted by TI_3VOM: I have an '88 5-speed coupe that I'm planning on rebuilding/modifing. How many of these mods are applicable to post-'87 tech 4s? I already know that the Holly aftermarket TBI and intake runners will NOT bolt up to these engines sans physical modifications (read; mounting plates). Any thoughts as to a PFI system for the Duke? Can I get by with the block from the '88 Fiero, instead of sourcing the S-10 block? Will I need to modify/replace the DIS, or can it be used as is? I'll ask more when I think of some more questions. Thanks.
The fiero I am building is an 88 5-spd! Many of the mods will apply to the 88. The big differences will be the TBI (as you mentioned), crank, block, and spark system. If you want to keep the stock computer/emissions you cannot change either. I don't think the wiring for the 88 TBI is the same as the Holley so you may want to look into this before you go through the trouble of making an adapter plate. You can buy an adjustable fuel pressure regulator from GM, and it MAY be possible to bore the stock TBI out a little. If you need to go further than that it's either carbs or custom computer. Also the 88 crank drives the oilpump, force balancer, and signal for the DIS. It may be possible to adapt an s-10 block to the 88 Fiero crank and the DIS. Later model s-10s may have well come with the same revisions as the 88 Fiero, but you will need to verify this as well as verify that the stronger casting was not revised (to be weaker). After market coils, and multispark boxes are available for DIS.
You may not want to run your 88 block at 7000, Consider this in your build up and go for more torque in the 5000-6000 range. You can buy hyperuetectic pistons for your 88 for $17 ea. and it will save you from having to get your head and deck milled (assuming they are in good shape).
I know of a person with a Fiero that was converted to the CIS system like the one out of a VW. Seems like it would be alot of work for the gain though.
Erik-
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03:31 PM
htexans1 Member
Posts: 9114 From: Clear Lake City/Houston TX Registered: Sep 2001
The part number for the mercruser cam is 424-3864 and retails for 150.06 (net cost) Kansas Racing Parts Company of Chapman Kansas makes parts (blocks heads etc) for racers. THese engines are all based on the IRON DUKE. Some of these parts are "super Duty" spec parts and many of these parts will work on Fiero 2.5's. S.Williams 1988 Fiero (with a dead Northstar)
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09:19 PM
Indy Tim Member
Posts: 93 From: Crystal Lake, IL Registered: Mar 2002
Wow computer was down for a couple days and this thread is really moving along. I thought about getting a computer chip burned Erik but I think I'd much prefer to take over the fuel management and idnition directly and have some sbility to modify it thats why I'm saving for the TEC II System. I may offer this motor as a crate engine from my shop if demand is high enough.
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04:22 AM
Indy Tim Member
Posts: 93 From: Crystal Lake, IL Registered: Mar 2002
If you do offer it as a crate, I may be interested. Won't be able to do it till next summer though. But come next summer, one way or another, I'll be looking for the rebuild you posted here. It would be much nicer getting it from you, than having to do it myself. Either way, I printed out the thread and saved it to my file. 195hp in an Indy? Count me in!
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10:28 PM
Oreif Member
Posts: 16460 From: Schaumburg, IL Registered: Jan 2000
Well Finally got my computer up and running reliably again. Anyway Just wanted to check this thread. If you are interested in a crate engine let me know by E-mailing me direct. I'm only going to go to the trouble of building it in crate form if there is enough demand.
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02:26 AM
erikred Member
Posts: 246 From: columbus, OH USA Registered: Nov 2000
I just remebered talking to a fellow who had success using a Kenne Bell Boost-A-Pump on his 180hp turbo Duke. It was the only thing he used to control fuel delivery. I wonder if it would work for a non-turbo engine?
Erik-
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05:01 PM
Apr 30th, 2002
erikred Member
Posts: 246 From: columbus, OH USA Registered: Nov 2000
i'd be interested if it were a direct swap. and if the price was right. around 1000 dollars would be nice with everything to drop it in and run. let us know if you do start making crate engines. how long do oyu expect this engine to last? 30thousand miles?
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02:01 PM
erikred Member
Posts: 246 From: columbus, OH USA Registered: Nov 2000
Originally posted by AgentD: i'd be interested if it were a direct swap. and if the price was right. around 1000 dollars would be nice with everything to drop it in and run. let us know if you do start making crate engines. how long do oyu expect this engine to last? 30thousand miles?
Wouldn't we all like it done for us for $1000? That would be a bargain considering they sell for $1500 with a bone stock rebuild and come with all the weak/cheap parts and that is just the long block.
Erik-
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05:17 PM
AgentD Member
Posts: 164 From: Enterprise, AL USA Registered: Dec 2001
Well, I have been watching this tread. It seems to have stalled. I have not seen any real numbers from this build-up.
erikred- Here is something for you to plug in Dyno2000....
4.040 bore 3.25 stroke
CFM on SD head 230 CFM on my ported head 205 CFM on stock Fiero head 110
I had crane cut SD grinds on blank OEM 2.5 cams in order to run the 3 bearing cams. SD cams are 5 roller bearing.
If you need the lifts, I will try to find a spec card.
Now, this tread reminds me of 1995-1998... I built 52 2.5 engines that turned 7600 rpm and live to tell about it. We ran Methanol Alcohol however. Cools the combustion and helps to keep from cracking heads.
I shaved the blocks .090 and the heads .120 in some cases.
The rods were 6.128 or 6.123 …. I would have to look that one up.
You can run a HOLDEN flat top piston with the rod and crank combination I came up with.
I still have 6 or 8 cylinder heads here in the shop that have been aggressively ported. I have installed 2.02 valves, and several other custom sizes to find the best flow on the bench.
There are 16 different “R” motor heads. Some of the casting numbers are :
767 552 373 808 437 702
Too others I cant remember. I have books with all that stuff.
The cranks you guys want to use are no longer made and very hard to find. The cranks that will live to 7400 RPM are casting 311, but these are only 3 inch stroke’s.
Well I'd have to do a little bit of cost analysis but I'm thinking I can probably kick the crate version out the door for around the $3000 canadian mark. Of course the crate engine will have to be even more refined than the version I'm running right now. I'd also like to look into building a Turbo version when I have more time available. Whoever posted about their Fuel management system please PM me as I'm very interested in this unit.
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01:30 AM
erikred Member
Posts: 246 From: columbus, OH USA Registered: Nov 2000
Fastfieros where have you been hiding all these years??? I have always been interested in the Duke and have been researching Iron Duke performance very heavily for the last two years. The most frustrating thing is that no one wants to give up any information and I know it is out there, and now tou have proven that!! You wouldn't believe what a had to go through just to get the very basic info that should be common knowledge. One guy actually wanted to charge me for basic build up info!
So now that the cat is out of the bag you are going to have to tell us what you know I hope I don't drive you crazy with my questions. The following questions concern Dukes of all years.
What types of books/litterature do you have? The only thing I have is an old GM Performance parts cat. and the Pontiac Performance Plus manual.
What factory cranks will handle over 6K RPM?
Have you ever used a crank with the force balancer for performance?
Are any of the factory rods usable or are they all junk?
Which Holden piston is the one that works? Was the 2.5 also sold as a Holden? Did any other countries ever manufacture this engine (maybe with some goodies on it)?
Do you have more specific flow numbers for the heads, such as ____cfm @ ___" of lift? Basicaly a chart of what the heads flow at certain valve lift intervals.
What's the skinny on the stock blocks?
Do you have Books/litterature on casting numbers/differences for the various parts?
Are any of your books for sale?
Are any of your parts for sale?
How much RPM and power do you think a Duke will handle if built up using the best STOCK parts?
What is the best stock casting (by stock I mean non-SD4) head to use for HP?
What valve sizes work best on stock/ported heads? Any pointers for preping the heads?
Have you ever done a turbo Duke? How about NOS?
Are there any stock parts that stand out as the ones to have (intakes, manifolds, ect.)?
Technician and Fastfieros, thanks for the info!!!!!
Erik-
[This message has been edited by erikred (edited 05-07-2002).]
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11:50 AM
PFF
System Bot
Indy Tim Member
Posts: 93 From: Crystal Lake, IL Registered: Mar 2002
>>>>Fastfieros where have you been hiding all these years???
Quietly working on V6 and V8 motors avoiding the little 2.5’s…….
>>> I have always been interested in the Duke and have been researching Iron >>>Duke performance very heavily for the last two years. The most frustrating >>>thing is that no one wants to give up any information and I know it is out there,
I have tons of it. Problem is, I am not sure where it is. That was 95-98 I messed with these.
>>and now tou have proven that!! You wouldn't believe what a had to go through >>>just to get the very basic info that should be common knowledge. One guy >>>>actually wanted to charge me for basic build up info!
There is A LOT of time involved in figuring out these combinations. Some feel, you can go blow up 10 motors trying this and that.
>>>>So now that the cat is out of the bag you are going to have to tell us what you >>>>know I hope I don't drive you crazy with my questions. The following <>>>>questions concern Dukes of all years.
I have forgot so much, but I will try. >>>>>What types of books/litterature do you have? The only thing I have is an old >>>>>>>GM Performance parts cat. and the Pontiac Performance Plus manual.
None of the above. I have seen SD write ups. Contact Bodix and see if they are still messing with the 2.5 808 Alumunium head. They use to do the 437 head, but discontinued that in 95. A group of 30 racers tried to get them to do the 437 again and they were not interested. The 808 will fit, but the intake is different from the Holley unit you can buy still like on ebay.
>>>>>>What factory cranks will handle over 6K RPM?
Casting number 311 will handle 7400 RPM all day if you balance it. Casting number 552 you will not find I bet. It will handle 8000. It is a forged crank from Mexico and was produced in 70-77 for some NHRA guys running chevy II’s. The stroke is awesome. 3.25 inches. I have one still………and it is not for sale.
>>>>>>>Have you ever used a crank with the force balancer for performance? I guess you are referring to the counter balancer?
No, it will not handle past 5500… We tried. We failed…..
>>>>>>>>>Are any of the factory rods usable or are they all junk?
GM rods are JUNK……. I know some import rods that work, but require boring the crank end and the pin end. Nice forged rods however.
>>>>>Which Holden piston is the one that works? Was the 2.5 also sold as a >>>>Holden? Did any other countries ever manufacture this engine (maybe with >>>>some goodies on it)?
I cannot remember this part number. I will have to dig out OLD receipts I kept and get the numbers I ordered there. That will try time. I have it all in storage.
>>>>>Do you have more specific flow numbers for the heads, such as ____cfm @ >>>>>___" of lift? Basicaly a chart of what the heads flow at certain valve lift >>>>>>intervals.
I gave you the CFM on the SD, stock, and my ported head. The numbers are at .040 lift I think. I have spec sheets, but I am not sure where they are. Maybe with the receipts. I know the CFM numbers are right, but lift might have been max lift of the cams which was ???? I forgot…….
>>>>What's the skinny on the stock blocks? The S-10 block was the only block to use with the beefed up webbing in the lower end. You need for the bigger cranks and high RPM’s.
>>>>Do you have Books/literature on casting numbers/differences for the various parts?
I have books from parts stores and racer warehouses that someone dug in the storage rooms for me. They are old and not for sale. Also in storage.
>>Are any of your books for sale?
No.
>>>Are any of your parts for sale?
YES, all of them. Wait till you see all the 2.5 stuff I have.
>>>How much RPM and power do you think a Duke will handle if built up using the >>>best STOCK parts?
The Duke will PUKE at 5800 RPM with stock parts. I know, I tried so hard to use them in 6 motors. Finally gave up…. Man did I buy some cool stuff.
>>>>What is the best stock casting (by stock I mean non-SD4) head to use for HP?
702 …… I have 2 of them. They are very hard to find. Mine are like new.
>>>What valve sizes work best on stock/ported heads? Any pointers for preping the >>>heads?
This one is gold I have to say. It took weeks and many motors to figure this one out. I cannot even remember the sizes, but they are available and I would have to get the receipts out and see what part numbers they were. The sizes will surprise you.
>>>>>Have you ever done a turbo Duke? How about NOS?
No and No. We racers could not use these. I built 25% of the guys engines that raced in our association.
>>>>Are there any stock parts that stand out as the ones to have (intakes, >>>manifolds, ect.)?
Just the heads and blocks. Everything else is billet or forged, and expensive.
Now, on this 2.5 motor build price. We stayed in the $3500 range for 225 HP….We started with a $100 motor and then had $3400 to spend.
We used mechanical fuel injection. I used Haltech EFI F7 boxes for a while also. I worked with Haltechs R&D from 93-96, then Australia decided the R&D department should only be in Australia.
Wow, I can't believe I finally found someone who knows what they are talking about when it comes to Dukes. Thanks for all the info, it helps sooo much. Now get ready for the next round of questions!
Is that round port head with the swirl ports the 702 casting?
What vehicles should I look for to find a 702 head and 311 crank?
Are the swirl port heads a good canidate for HP? Everyone claims they are junk. The heads I have on my 355 Chevy are swirl port and very similar to the 2.5 swirl port, but have conventional small block cumbustion chambers. I ported them out very similar to the picture you have and they run great.
Whats up with that head that has been welded so much?
Do you think $500 is a good price for a forged crank?
Do you have any experience with the Marine engines (specificaly the 3.0 crank rods and pistons)?
Someone who used to build SD engines told me the problem with these engines was the oiling. Can you verify this? If so how did you get around it?
Are those the import rods and Holden pistons you mentioned?
This is a very interesting thread since I am going to pick up my old 84 T-Top turbo duke from Ed Parks in the next 7-10 days.
I am definetly going to start the 195hp duke build but I cant have 9.8 to 1 since it is a turbo charged engine. The car already has the Holley intake and T/B on it (the ones sold for the fiero) so I am ahead of the game on that one. If I follow your build up and not deck the block or head do you have any idea what the CR would be? I hope for 8 to 1 or so. maybe even 8.5. Thank you for sharing this info. Some would offer to sell the "package" engine and not give the details. Oh, I was thinking about the megasquirt or the engine mamagement in the better than sliced bread thread to tune the 195 duke w/ turbo set up. What do you think? I'll keep you posted.
Steven
------------------ 87 Fiero GT 14.9/ 89mph 94 Formula WS6 w/ NOS 12.4 /118mph 87 Conquest TSi 87 Conquest TSi 406 SBC V8! 85.5 Starion ESi
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09:58 PM
May 9th, 2002
FastFieros Member
Posts: 2698 From: Dallas Texas USA Registered: Nov 2000
>>>>Wow, I can't believe I finally found someone who knows what they are talking >>>>about when it comes to Dukes. Thanks for all the info, it helps sooo much. >>>>Now get ready for the next round of questions!
Here we go, round 2 Q&A >>>>Is that round port head with the swirl ports the 702 casting? NO, that is custom I built. There is 40 hours in welding, and porting and shaping those ports. Welding cast iron is an art. I have a Miller SynoWave 351 TIG with a micro torch to weld deep In those ports. Then you have to preheat the cast area to 400 degrees to weld there without cracking. Its the cool down process that sucks. The 702 is a cross flow head. In these 2.5’s you want straight as possible in and out. Look at the brodix head cast number 437. That head is straight on number 1 and 4. Well, to make a better thing, they did the 808. This head is straight cross flow on 1-4. I know a guy in Oklahoma city that cuts heads in half and welds and ports them, then puts them back together. Very expensive to do that. He only does this to aluminum heads however. >>>>What vehicles should I look for to find a 702 head and 311 crank? I have not idea. I purchased mine from the reman builders. You just ask someone in there if they have 702 heads instead of 767 heads. The 767 was the most popular known because of its cracking. The 808 is what is on most 88-92 cars. Here is where you look for the numbers. If the valve cover is off the head. Look for the casting number around #3 and #4 valve area. It will be a long 8 digit number, but you are concerned with the last 3 digits only. Now, if the head is not off, look at #3 spark plug hole. Take the plug wire off and scrape all the oil and junk off, there should be 3 numbers there. Not all heads had those numbers at the #3 hole however. I have seen 767, 373, 552 and several others on that #3 hole. There are a couple of other cross flow heads, but the water jackets are thiner when porting those.
>>>>Are the swirl port heads a good canidate for HP? Everyone claims they are >>>>junk. The heads I have on my 355 Chevy are swirl port and very similar to the >>>>2.5 swirl port, but have conventional small block cumbustion chambers. I >>>>ported them out very similar to the picture you have and they run great. Swirl are junk. It was fuel economy, not performance. Are you are sure you are not confusing the tear drop combustion camber as the performance feature. It was. The tear drop exhaust enhances “drawing” in the next fuel charge. This area is to be polished like glass mirrors. Clean Clean Clean fuel mixtures will keep the head from building carbon and messing this up. Well, I removed my heads every 6 races and replaced the valves to keep the seats fresh. I saw strange things that had to do with combustion, but that is another topic.
>>>>Whats up with that head that has been welded so much? The water jackets and dead oil drop areas were closed off on the intake side. I didn’t have water going in the intake since I had alcohol cooling the thing. You will not need to do this, however, if you want to reshape that intake port for better matching, you will have to do some welding and reshaping. I have several examples of this. >>>>Do you think $500 is a good price for a forged crank? Very good price. IF I sold mine it would be at least that much.
>>>>Do you have any experience with the Marine engines (specificaly the 3.0 crank >>>>rods and pistons)? Yup, I and others tried the marine 3 inchers. Boy is that one heavy crank. It will turn about 6800 to 7200 and then it breaks in half.
>>>>Someone who used to build SD engines told me the problem with these >>>>engines was the oiling. Can you verify this? If so how did you get around it? SD’s I ran didn’t have any oil problems, however, I used custom 6 quart pans. I used the M62C oil pump. I hope that number is right. Trying my best to remember this stuff.
>>>>Are those the import rods and Holden pistons you mentioned? Those rods,,,,,,,,, haaaaaaa, the good stuff. Crower rod and a Childs and Albert. Those are some RPM turning rods. That Crower is HOT at the crank end, thanks to a 5 quart oil pan, and that Childs and Albert is bend ever so slightly thanks to a valve keeper coming apart. That piston is the Holden with a nice valve mark from the keeper coming off.
TI_3VOM >>>>Fast.... >>>>What do you know about EFI for the Duke? Any aftermarket setups? How >>>>about modifing the EFI from another GM 4-cyl for use on the Duke?
The Haltech F7 box works, been there done that. Might still have some maps on a 386 computer I actually still have. You need bigger injectors to match the flow of those big heads. That means injectors that are not going into saturation. Very important to have the right injector.
>>>>This is a very interesting thread since I am going to pick up my old 84 T-Top >>>>turbo duke from Ed Parks in the next 7-10 days.
Good luck on the trip….. BV MotorSports >>>>I am definetly going to start the 195hp duke build but I cant have 9.8 to 1 >>>>since it is a turbo charged engine. The car already has the Holley intake and >>>>T/B on it (the ones sold for the fiero) so I am ahead of the game on that one. >>>>If I follow your build up and not deck the block or head do you have any idea >>>>what the CR would be? I hope for 8 to 1 or so. maybe even 8.5. >>>>Thank you for sharing this info. Some would offer to sell the "package" engine >>>>and not give the details. >>>>Oh, I was thinking about the megasquirt or the engine mamagement in the >>>>better than sliced bread thread to tune the 195 duke w/ turbo set up. What do >>>>you think? >>>>I'll keep you posted.
TB from holley will never make enough flow or injector size for a 195 HP motor, I don’t think.
I missed 2 of your ??????
I have megasquirt in my hands now. I have read and read all the stuff. Still need to sit down and build the sensor spoofer to calibate the thing.
OK, on the piston deal. With a 3 inch stroke, and stock type piston, you have .090 to deck. With a 3 inch and a holden,,,,, Hummm, I forgot the numbers on this one.
With a 3.25 inch stroke and the holden piston, you have .006 to much piston....Guess what, mill and fly cutter time. Easy zero deck. Lots of meat on the piston.
Thank you all, Loyde
[This message has been edited by FastFieros (edited 05-09-2002).]
[This message has been edited by FastFieros (edited 05-09-2002).]
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12:08 AM
TheTechnician Member
Posts: 177 From: Bentley, Alberta , Canada. Registered: Feb 2002
Ok I have a question for you fastfieros. what did you do in the way of intake? Cold air or just open and relying on the alcohol to cool things down? ......... Oh ya whoever asked if you don't deck the s-10 block CR will be sitting right around 8.2:1. Providing you have a block that has never been touched and it measures out to the factory blueprint spec.
[This message has been edited by TheTechnician (edited 05-09-2002).]
Do you have info on contacting them?
