hello all. I was just wondering, I know that the manifolds will be different, and the chambers are smaller, but if I used the newer aluminum (87?) heads on the older 2.8 HO, what would my compression be? I can most likely get my hands on a set of these heads fairly cheap.. just wondering if I would have to run nitromethane in it to keep it from pinging
thankyou all..
Jude
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12:05 AM
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donk316 Member
Posts: 1952 From: Red Deer, Alberta, Canada Registered: Mar 2003
DUDE! Whatever someone says allong the lines of "cant be done" and "it will blow up" they are dumb
Without modifications youll be running 16.6 to 1 compression. Swap your pistons (yuck) or open up the CC's or/and thicker head gaskets.
I am putting GEN3 heads onto a 3.4 right....now.
Heres the thing....the GEN2 heads are better than the fiero heads but the intake manifolds for the GEN2 suck ass. Look for a 3100 or 3400 top end (heads and intake) ------------------ Calgary - August 1, 2004 Fiero Fiesta 1984 Indy Fiero 3.4/3100 Hybrid NA *ALL THROTTLE AND NO BOTTLE*
[This message has been edited by donk316 (edited 06-07-2004).]
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12:11 AM
jude Member
Posts: 65 From: ontario, canada Registered: Jun 2003
how will I "open them up"? like the heads are non-siameesed ports.. kinda like the 3800 heads.. but if I can get these to work, I will try it..
I gotta get the compression down under 9.5:1, otherwise, I wont be able to run on pump fuel for sure, and this is supposed to be a streetable car.. I will be interested in seeing what that other person comes up with for the Eaton M90 install.. that would be another nice thing sitting atop the engine, but I would need the stock 8.5:1 compresson then!
so, the heads off the 3.4 seriousally flow better? I thought the only difference was the pistons and crank?
oh whell, yeah.. aluminum heads would be nice, but not at a 16:1 compresson!
whell, its late.. so talk later!
Jude
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12:18 AM
donk316 Member
Posts: 1952 From: Red Deer, Alberta, Canada Registered: Mar 2003
how will I "open them up"? like the heads are non-siameesed ports.. kinda like the 3800 heads.. but if I can get these to work, I will try it..
I gotta get the compression down under 9.5:1, otherwise, I wont be able to run on pump fuel for sure, and this is supposed to be a streetable car.. I will be interested in seeing what that other person comes up with for the Eaton M90 install.. that would be another nice thing sitting atop the engine, but I would need the stock 8.5:1 compresson then!
so, the heads off the 3.4 seriousally flow better? I thought the only difference was the pistons and crank?
oh whell, yeah.. aluminum heads would be nice, but not at a 16:1 compresson!
whell, its late.. so talk later!
Jude
Open up the combustion chambers not the runners. Who says 9.5 to 1 is the limit for streetabilty?? Not 3.4 heads, 3400 heads, 3.4 is basically a 2.8 iron head but the 3400 head is newer and aluminum, flows waaay better and smaller combustion chambers.
Donk, seems you've been answering a lotta questions about these heads and such so I went downstairs and took these pics off my workbench (an old pool table, lol) using some spare parts I had around... They're on personal space, so feel free to link to them whenever, if the subject should come up..
Dude, I really appreciate those pics.words cannot express how...surprised(?) i am that you would do that. wow. Hey....if you wanna snap a pic of that GEN3 intake next to a Fiero lower intake that will complete the set! You have all that laying around?? Bolt it on!
Now if those pics dont CONVINCE you that hybrid swapping is the way to go you need your head examined...or go bolt in a 350. Yeah thats cool...(insert rolling eye smiley here) lol!
------------------ Calgary - August 1, 2004 Fiero Fiesta 1984 Indy Fiero 3.4/3100 Hybrid NA *ALL THROTTLE AND NO BOTTLE*
[This message has been edited by donk316 (edited 06-07-2004).]
Those newer aluminum 2.8-3.1 heads are superior to the old heads for one good reason....the valves are "canted"... when the valves open they are moving away from the cylinder walls and provide a flow advantage the same way HEMI heads do to make great power. Unfortunately these heads are hard to adapt to a fiero block. Compression will be vey high unless deep dish pistons are used. The heads will not bolt up to a fiero intake. The intakes that fit on these heads will not allow a distributor to be used... so you will have to run a coil pack distributorless ignition system which will require a different computer and wiring harness...... In other words It would be easier to run a complete engine that comes with these heads than to do a retro fit job.
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01:09 AM
donk316 Member
Posts: 1952 From: Red Deer, Alberta, Canada Registered: Mar 2003
Those newer aluminum 2.8-3.1 heads are superior to the old heads for one good reason....the valves are "canted"... when the valves open they are moving away from the cylinder walls and provide a flow advantage the same way HEMI heads do to make great power. Unfortunately these heads are hard to adapt to a fiero block. Compression will be vey high unless deep dish pistons are used. The heads will not bolt up to a fiero intake. The intakes that fit on these heads will not allow a distributor to be used... so you will have to run a coil pack distributorless ignition system which will require a different computer and wiring harness...... In other words It would be easier to run a complete engine that comes with these heads than to do a retro fit job.
Another non-believer! Welcome to the church of Hybrids!
umm yes and no. Anything can be done if you ACTUALLY try it. its more hassle swapping ecms and wiring harness's than using a little ingenuity and thought.
------------------ Calgary - August 1, 2004 Fiero Fiesta 1984 Indy Fiero 3.4/3100 Hybrid NA *ALL THROTTLE AND NO BOTTLE*
[This message has been edited by donk316 (edited 06-07-2004).]
You are DA man! That one of both intake looking at the cold start injector is exactly what i was looking for! Wooo! I saved every pic incase another nay-sayer comes along. Right on!
If you have all that laying around, either swap it or sell it! Lots of goodies there...
donk316 I am not sure what you mean by all the "negative?" talk about just swaping the entire engine? But you seem to glaze over the fact that the heads in the newer engines are not the only thing that is better than the Fiero stuff. Or maybe you just dont know that the newer engines have a better oiling system, front timeing chane cover and cooling system too. The newer engines will last longer because of better machining tolerances and a lower stressed oil pan/girdle. If you what to "Hybrid" yours that is cool but dont put me and others down because we chose to put the entire engine in. IMHO the Fiero 2.8 is not the way to go. You will be better of to go throu the extra troble of swapping the Fiero engine out for the newer blocks/heads and electronics that are all better than the Fiero stuff. Yes it is more work than just swapping out the top end but you will still have to reprogram the ECM and rework the fuel curves and all the rest of the conversion stuff just to do the top end. So is it realy easier?
------------------
Rickady88GT QuadCam 3.5 V6
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12:39 PM
DanielKJenkins Member
Posts: 439 From: Denison, TX USA Registered: Jun 2003
Cylinder pressure is a result of mechanical compression ratio and cam timing.
A long duration cam with a large "overlap triangle" will reduce cylinder pressure.
Polished combustion chambers will reduce detonation by evenly distributing the heat across the combustion chamber.
Aluminum heads conduct the cc heat much more than cast iron. Higher CR's can be run on AL heads without detonation.
A lower overall operating temp will reduce detonation.
It seems to me that an 11.5:1 cr on a properly prepped AL head engine would run on pump gas if the ignition timing was really well dialed in.
A 275HP 3.4. Go for it Donk.
Oops I hijacked the thread..sorry. The AL heads might work if you perform significant mods. Just bolting them on over the cast iron pistons won't work.
If you are wanting a quick swap just find the iron heads.
[This message has been edited by DanielKJenkins (edited 06-07-2004).]
Right, I'm kinda just following along with this also. I can't wait to see how this turns out. I have the complete 3400 block here as well and am debating swapping in this engine entirely, or putting iron heads on it running the fiero intake with mucho boost. Perhaps swapping the full 3400, using the better block with the better heads, the better dis system, and throwing this nitrous kit on it.
But then the 3.4 carb setup I have, I was intending on just getting a nitrous plate to bolt under the carb, and juice that thing.. Argh, I dunno anymore..
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02:21 PM
donk316 Member
Posts: 1952 From: Red Deer, Alberta, Canada Registered: Mar 2003
DanielKJenkins - Yes your absolutely right. sub 12 to 1 is easy to attainable on the street and for everyday use.
Rickady88gt - I understand where your coming from. I am trying to open the eyes of most owners that there is an alternative to swapping motors for more power. Or there are more choices available than the typical. Do you really think having a better timing chain cover and cooling system is worth swapping entire motor / wiring / ecm? Nothing wrong with the GEN1 system at all! Then swap more effiecent aluminum heads on. Not flamin you just trying to feel out where your coming from. The 3.4 block has a 'better' oiling system but a properly built 2.8 block (like mine was) can be bored and stroked to 3.4 and rev to 7000 rpm all day long. (like mine does) And then achieve close to 300hp on that block and a head/intake swap. (like mine will) And burning a chip has to be done no matter what swap you do so again. not a big deal.
The issue of DIS VS Distributor is a moot point. Distributors can and have made just as much reliable horsepower as the 'distributorless' systems. I dont see how they are an improvement. If anything its an added cost for aftermarket coil packs and coil wires that are 3 feet longer than they have to be. I would wager that the gains found through the system are lossed throught theadded resistance of the coil wires that now are twice as long in some cases.
I would consider the newer block when better cams are available.
Ill show you how the distributor works with the GEN3 intake when its done.
I think I covered everything.
------------------ Calgary - August 1, 2004 Fiero Fiesta 1984 Indy Fiero 3.4/3100 Hybrid NA *ALL THROTTLE AND NO BOTTLE*
[This message has been edited by donk316 (edited 06-07-2004).]
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02:36 PM
DanielKJenkins Member
Posts: 439 From: Denison, TX USA Registered: Jun 2003
I have an iron headed 3.4 that has had the valves unshrouded. My actual CR is 9.3:1 (measured by my engine builder).
That means that I dropped .4 CR by reshaping the CC
Lowering the mechanical CR by removing material from the CC... In my case it was a consequence of unshrouding the valves (I removed as little material as possible to obtain ~3/16" clearance between the edge of the valve and the CC at the narrowest point). The cast iron head has VERY heavily shrouded valves at low lifts. I think that the CR drop will be more than offset by the increased flow at low lifts.
How much material can be removed from the AL head? Where would the material be removed from? .
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04:02 PM
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jude Member
Posts: 65 From: ontario, canada Registered: Jun 2003
the 3400 heads.. are they aluminum? do they need dished pistons?
and what kind of spacer / head gasket would I need to bring it down to 9.6 to 1? there isnt a cam in there now, and I thought I was going to go with a crane 2030 cam.. but what would be a wise idea?
I understood that the manifolds wouldnt fit, so I was going to build a set out of aluminum piping and put a nice big throttle body on it.. I know I know.. theres alot of math.. but I am prepared..
these newer aluminum heads.. would they physically bolt to my engine allrite? how about valve clearance?
thankyou..
jude
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11:02 PM
Jun 8th, 2004
Steve Normington Member
Posts: 7663 From: Mesa, AZ, USA Registered: Apr 2001
The 3400 heads are esentially the same as the 3.4 aluminum heads. The difference between 3400 and 3.4 aluminum is the 3400 if sequential fuel injection and the 3.4 aluminum is batch fuel injection. You would need dished pistons, and the intake from the 3400.
PS. The 3400 has roller rockers which is a big improvement over the flat rockers. But you can use them with iron heads.
The 3400 heads are esentially the same as the 3.4 aluminum heads. The difference between 3400 and 3.4 aluminum is the 3400 if sequential fuel injection and the 3.4 aluminum is batch fuel injection. You would need dished pistons, and the intake from the 3400.
PS. The 3400 has roller rockers which is a big improvement over the flat rockers. But you can use them with iron heads.
Your correct about the rockers but im a little lost as to what 3.4 came with aluminum heads.....are you thinking 3.1? The 3400 Gen3 head far outflows the gen2 3.1 head and also has a slightly bigger intake valve.
------------------ Calgary - August 1, 2004 Fiero Fiesta 1984 Indy Fiero 3.4/3100 Hybrid NA *ALL THROTTLE AND NO BOTTLE*
Donk you are going to use one of those crazy off set gear drives under the dis tibutor arnt you? I think what you are doing is cool. I like Fieros and want to see them kick but all ove rthe place. I just think that what works best for me or you aint always the best for others. Some, like me dont want or need all out race car engines. I want alot more power but it has to be smog legal and some what good on gas. So the only way to do it is a compleet engine swap. To me it seemed like you putting down the engine swap in favor of the head swap. That is why I chimed in.
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03:38 AM
donk316 Member
Posts: 1952 From: Red Deer, Alberta, Canada Registered: Mar 2003
hey no problem man different strokes for different folks...im trying to build one of the most powerfull 60 degree v6 pushrod motors ever put into a fiero with out n20 or a turbo....phew theres a mouth full!
No actually the distributor looks like it can be modified to fit by relocating the ignition module and reworking the cap. Do you think there is a market for these distributors? lol!
------------------ Calgary - August 1, 2004 Fiero Fiesta 1984 Indy Fiero 3.4/3100 Hybrid NA *ALL THROTTLE AND NO BOTTLE*
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03:43 AM
Rickady88GT Member
Posts: 10649 From: Central CA Registered: Dec 2002
In theory and on paper this combo is good for 317hp so we will see what happens...hoping to be dyno ready and tuned by August 1st.
Remember my motor is far from stock and the top end swap is the last piece of the puzzle. Dont read this and assume these heads and intake on your motor will get you 300hp!
Wait till you see this thing... ------------------ Calgary - August 1, 2004 Fiero Fiesta 1984 Indy Fiero 3.4/3100 Hybrid NA *ALL THROTTLE AND NO BOTTLE*
[This message has been edited by donk316 (edited 06-08-2004).]
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04:43 AM
Will Member
Posts: 14257 From: Where you least expect me Registered: Jun 2000
Yes, there's potential in the 60 degree 6 platform, but it has to be built... the factory combinations just aren't that great...
The 2.8 and the 3.4 in F-bodies and the 3.1 in early minivans all had iron heads The passenger car 3.1's had the gen2 heads (early style aluminum heads/intake) The 3100 and 3400 had the gen3 heads (late style aluminum heads/intake)
No 3.4 was ever offered with the gen2 heads.
All gen2 and gen3 engines have DIS. The iron head 3.4 also had DIS. I dunno about the iron head 3.1. The iron head 2.8 of course used a dizzy.
I think an outstanding combo would be a DIS 2.8 crank in a roller cam 3400 block with 6+" rods and maybe Northstar or custom pistons.
That rod ratio would let you run a LOT of compression... prolly 12.5 on 93 octane would be workable.
As far as DIS vs. dizzy... Distributors are old technology. They have one coil firing 6 cylinders, spark scatter, and in general the monkey business associated with mechanical complexity. DIS is really not very difficult. ALL the gen2 engines used the 7730 computer. That's the same computer used in late '80's early '90's Vettes and F-bodies and has been hacked every which way from here to Timbuktu. IOW, reprogramming this computer for use in a Fiero is easy and there are a number of outfits that can do it easily. The equipment to reprogram the computer yourself is also only a few hundred dollars. The wiring is also not very difficult as swappers frequently have the Fiero V6 wiring with which to work.
I really don't see a good reason to NOT use DIS, especially if it's a lot of work to make the dizzy compatible with the later intake manifolds. If you're going to the trouble of building an outstanding 60 degree 6, you might as well use the best ignition system for it.
------------------ '87 Fiero GT: Low, Sleek, Fast, and Loud '90 Pontiac 6000 SE AWD: None of the Above
Luck, Fate and Destiny are words used by those who lack the courage to define their own future
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10:25 AM
jude Member
Posts: 65 From: ontario, canada Registered: Jun 2003
allrite.. .. .. so basically, if I wanna run aluminum heads, I would have to either get dished pistons, or get the chambers opened up alot more.. right? the 3400 heads on the flat top pistons would still give me like 16:1 compresson?
thankyou..
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11:57 AM
Joe Torma Member
Posts: 3485 From: Hillsborough, NJ USA Registered: Jul 2001
I feel I modded the %#$# out of my 3400, and destop dyno says I should have 300hp. I guess the key to your high hp is compression, but I fear running such high cr on pump gas. I can program whatever spark curve I want with my Electromotive TEC-II, but still, I dunno about 12:1, it seems a bit high. GM was able to get 300hp out of the bowtie 2.8 block...I don't know the specifics though.
[This message has been edited by Joe Torma (edited 06-08-2004).]
DIS on a Fiero 2.8 is going to be a "bit" of a challenge. There is this little issue of a crank sensor. Even if you machined a hole for it in the 2.8 block, you would still have to swap out the crank, as the 2.8 crank does not have the notch ring. If you swap the crank, there is a new set of pistons biting your wallet. You might get by with a modified MSD crank trigger, but I have yet to here of anyone successfully using that approach, and at $230 it’s certainly not a cost saving idea. Probably cheaper than the 3.1 pistons though.
The yards are full of low mileage (<20k mi) GEN III 3100 and 3400 motors right now, and you can typically obtain one of these for less than $400. A swap using these motors is really quite straightforward, if not downright easy.
The performance increase offered by a stock 3100 / 3400 over the stock 2.8 would likely not justify the swap. But, if you consider that you can bolt a turbo onto a GEN III motor using a $20 flange with no welding required, the swap gets a bit more interesting. Here is the flange in position on a 3100 exhaust manifold :
Here is the 300 hp full roller 3100 powertrain that results from 14 PSIG of boost provided by the turbo bolted to the flange.
The motor used started as a brand new 3100 GM replacement unit, but it is far from stock, with internal modifications such as custom forged low compression pistons. The entire project still cost less than the typical performance V8 crate motor alone. Weighs less, no "kit" needed, goes real fast..
The Turbo Grand Prix based forced induction engine management system is fully programmable in real time. It also offers more areas of real time tuning than any aftermarket system, and does this wirelessly. IOW, you just walk up to the car with any laptop equipped with a wireless network card, and you can start tuning immediately.
DIS on a Fiero 2.8 is going to be a "bit" of a challenge. There is this little issue of a crank sensor. Even if you machined a hole for it in the 2.8 block, you would still have to swap out the crank, as the 2.8 crank does not have the notch ring. If you swap the crank, there is a new set of pistons biting your wallet. You might get by with a modified MSD crank trigger, but I have yet to here of anyone successfully using that approach, and at $230 it’s certainly not a cost saving idea.
Actually, DIS on a 2.8 isn't very hard at all. GM built quite a few of them with the Gen 2 heads and intake.
------------------ '87 Fiero GT: Low, Sleek, Fast, and Loud '90 Pontiac 6000 SE AWD: None of the Above
Luck, Fate and Destiny are words used by those who lack the courage to define their own future
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08:44 PM
donk316 Member
Posts: 1952 From: Red Deer, Alberta, Canada Registered: Mar 2003
Its not hard to retro fit DIS to a non DIS block and crank. Ever heard of crank trigger systems? click here
Dont give me any crap about "no kit listed for out motor" the only differences are the mounting brackets. If you cant fab mounting brackets your in the wrong thread.
If you havent guessed I hate the work "KIT" lol!
[This message has been edited by donk316 (edited 06-08-2004).]
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09:41 PM
Jun 9th, 2004
donk316 Member
Posts: 1952 From: Red Deer, Alberta, Canada Registered: Mar 2003
The Turbo Grand Prix based forced induction engine management system is fully programmable in real time. It also offers more areas of real time tuning than any aftermarket system, and does this wirelessly. IOW, you just walk up to the car with any laptop equipped with a wireless network card, and you can start tuning immediately.
dude, give me more info on this system, dont care about the forced induction end of it though...just the hardware and stuff..
------------------ Calgary - August 1, 2004 Fiero Fiesta 1984 Indy Fiero 3.4/3100 Hybrid NA *ALL THROTTLE AND NO BOTTLE*
LOL.
