What is the difference between the 3.4 iron head and the 3.4 alluminum (is it pretty much the same deal as the 3.1 to the 3100?)
While it looks like the aluminum heads have larger ports, I believe they have smaller valves, so actually flow less air than the iron heads. 3.4 iron heads are exactly the same as the 2.8 and 3.1 iron heads.
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On my 2.8 the valve covers leak like a sieve even though I just put new gaskets on them. I've spoken to some other guys and they say the 2.8 is notorious for leaking at the valve cover. Does the 3.4 have this problem?
If you go with iron heads, these will be the same as the Fiero heads, so be prepared for the same issue - if you can find the neoprene gaskets, they are supposed to seal better than the other ones.
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On and general automotive mechanics note, I was wondering if someone could explain to me more about rocker arms, rods and lifters. I don't understand why changing them increases performance or economy. What is the difference between a regular rod and a roller tipped rod. What does 1.6 arms mean? Why does swaping out one type of rocker for another change anything about the engine?
A rocker arm is just a lever, and accomplishes two things:
Because of the unequal length on each side of the fulcrum (the ball on the mounting stud) the rocker arm multiplies the cam lift by the rocker arm ratio to increase the lift at the valve. A 1.5 ratio rocker arm multiplies the lift by a factor of 1.5, whereas a 1.6 ratio provides 1.6 times the cam lift at the valve.
Rocker arms change the direction of the cam movement from an upward force on the tappet and push rod to a downward force on the valve stem.
Because of the speed of operation and the resistance to lift that the valve spring exerts, stock pushrods may flex, which slightly reduces lift and perhaps effective duration of valve opening. Stronger pushrods may be installed to eliminate this flex and give you the full lift and duration you paid for with a new cam.
Hope this helps.
Cheers
**EDIT - Rocker arm ratio is determined by the length of the rocker arm on each side of the fulcrum. If you take a look at yours, you'll see that the length from the fulcrum to the valve stem is longer than the length from the push rod to the fulcrum. For stock rocker arms this ratio is 1.5 (well maybe 1.52) to 1.
Rocker arms also multiply the force of the valve spring to the pushrod and tappet, by exactly the rocker arm ratio. So if you have a spring with a 300 lb force when the valve is fully open, the force on the pushrod is actually 450 lb, The more lift you have, and the higher the RPM you expect to push the engine, the heavier the valve springs you need to ensure that the valve actually stays on the seat during the compression stroke. A performance pushrod engine requires upgraded pushrods to deal with the forces exerted by the valve spring.
[This message has been edited by TiredGXP (edited 07-10-2008).]
Does anyone here with a 3.4 have the problem with the leaky valve covers?
Also does anyone have anything to say about getting this engine to 200HP? I am really interested in this swap but I would really like to have that kind of power.
Does anyone here with a 3.4 have the problem with the leaky valve covers?
Also does anyone have anything to say about getting this engine to 200HP? I am really interested in this swap but I would really like to have that kind of power.
Thanks again,
People say the intake is limmited at around 190HP(without boost), they also say it is too small for the 3.4 BUT that is at 100%VE wich these(or any) engine does NOT have. I can only guess I was about 180-190HP before the turbo. (mine was the fastest 3.4 swap that I have done/driven). Carb setups have been done with good results in power (I don't know what else was done but over 200HP). any 2.8L mods apply so any and all mods can be used with the 3.4L
And the heads are the exact same as the 2.8L so the same design as far as the way valve covers go on.
Thanks for all the responses, I never thought that this thread would get so big when I started it, no complaining here. (edit) dang over 36,000 views too.
Nice job on the rotors, BTW FYI cross drilled and slotted rotors can be bought on E-Bay for around $120 for all four. But first time I saw someone drill thier own, Chamferd holes Too, NICE.
Sorry, I read through the thread and I didn't catch the mods you did.
Could you fill me in on what you did to the 3.4 over and above stock?
thanks
My list of mods is on my laptop and it would take awhile to type it all out again. But for now, not counting some brackets, it is easier to just say the only things I didn't mod are the cam and throttle body. for now anyway.
Thanks for the thread. I'm in the middle of my 3.4 swap and all of this info has answered all of my questions. I got a great deal on a long block GM crate motor ($600) and I can't wait to get my car out of my garage. I've had it 4 years, the guy I bought it from (some of you know of DKOV) told me one of the injectors leaked. When it was delivered I checked the oil and it was nothing but gas (little leak indeed). So I picked up a low milage 2.8 to install but was having a hard time doing an engine swap with the same type of engine. The 3.4 I got was a deal and will get me on the road but eventually I want a 3.4 DOHC or 3800SC. Or maybe I'll just turbo the 3.4.
Thanks for the great write-up and pictures. I'll post pictures of my install when I get the motor together and ready to install. My car build thread is on another forum though. http://www.kitcarsforum.com...read-(sactodreamer)/
I used the old one By removing the part from the engine, it was going wrong, so I had to rebuild them. So I first cleand them and put it back to gether.
Ok, Now I have an '86 four banger, and I have been reasearching the different swaps for a while, I just wanted to get all of my facts streight before start anything because this car is my daily driver, and the only vehicle I have. Once I pull the old motor, the new one needs to go right in. I was looking at the Cadillac 4.5 for a while, but this seems to be more ideal. I know tha having a duke is definately going to hurt me on this, But I am just trying to get a complete list of what I need.
-2.8 stock parts ECM, and engine harness Distributor oil pan 88 flexplate (P/N was given earlier in thread) timing cover motor mounts coolant crosover pipe
-other parts complete prothane kit (might as well do it all at the same time) Rodney Dickmans starter template ( optional, but I don't want to take any chances) 3.4 motor from a 4th gen F-body
I will be taking my time and building the new motor, not just doing a junkyard swap, but for me, that is the easy part. My issue is that most of the cars that I have owned were gm V8 cars, most of which were produced in the 80's, and dealing with these motors, it's almost always just pull one, and drop in another. The other issue that I have, and the reason that I need all of my facts streight, and complete is that my friend who will be helping me is certainly not a facts kind of person. He is very happy to just throw it all together and see if it works, he has also never touched a Fiero (to my knoledge) and last week even tried to tell me that I would not have to relo my starter for this particular swap. Even after I looked it up on the forum, he argued it. (This is more a case of I need a place to drop my cradle, than that I need the help. I just can't see doing a motor swap on the street, in front of my apt, lol, and he has a garage)
I am also very familiar with the 3.4 as I did own a '95 firebird for several years. the 6 felt decent, but not spectacular. F-body's are notoriously lead boats, so I figure that in a car as light as the Fiero, this should have real potential, and I don't want to build a car with so much power that I can't street it, or drive in the rain. Anyway, I will most likely be starting my build by the beginning of July, so If I have left anything out, please let me know, thanks
Ok, Now I have an '86 four banger, and I have been reasearching the different swaps for a while, I just wanted to get all of my facts streight before start anything because this car is my daily driver, and the only vehicle I have. Once I pull the old motor, the new one needs to go right in. I was looking at the Cadillac 4.5 for a while, but this seems to be more ideal. I know tha having a duke is definately going to hurt me on this, But I am just trying to get a complete list of what I need.
-2.8 stock parts ECM, and engine harness Distributor oil pan 88 flexplate (P/N was given earlier in thread) timing cover motor mounts coolant crosover pipe
-other parts complete prothane kit (might as well do it all at the same time) Rodney Dickmans starter template ( optional, but I don't want to take any chances) 3.4 motor from a 4th gen F-body
I will be taking my time and building the new motor, not just doing a junkyard swap, but for me, that is the easy part. My issue is that most of the cars that I have owned were gm V8 cars, most of which were produced in the 80's, and dealing with these motors, it's almost always just pull one, and drop in another. The other issue that I have, and the reason that I need all of my facts streight, and complete is that my friend who will be helping me is certainly not a facts kind of person. He is very happy to just throw it all together and see if it works, he has also never touched a Fiero (to my knoledge) and last week even tried to tell me that I would not have to relo my starter for this particular swap. Even after I looked it up on the forum, he argued it. (This is more a case of I need a place to drop my cradle, than that I need the help. I just can't see doing a motor swap on the street, in front of my apt, lol, and he has a garage)
I am also very familiar with the 3.4 as I did own a '95 firebird for several years. the 6 felt decent, but not spectacular. F-body's are notoriously lead boats, so I figure that in a car as light as the Fiero, this should have real potential, and I don't want to build a car with so much power that I can't street it, or drive in the rain. Anyway, I will most likely be starting my build by the beginning of July, so If I have left anything out, please let me know, thanks
When you say 2.8 stock parts I hope you mean the whole Fiero 2.8 engine assembly. As you need everything execpt the block, not just a few block parts, everything. Also your 86 4 has a different A/C compressor, won't fit the 2.8/3.4. So you would have to get a different A/C compressor too.
In that case, will those parts interchange with the 2.8 used in the Camaro/Firebird? I think that it will be much easier to find one of those motors in a boneyard near me, as I spend a lot of time in the yards around here, and cannot remember ever seeing a Fiero with a 6 in it. I rarely ever see any at all. Also, it was said earlier that the motor had trouble breathing at higher RPM's. Is that caused from using the 2.8 intake? or could it potentially be solved by creating a ram air setup?
In that case, will those parts interchange with the 2.8 used in the Camaro/Firebird? I think that it will be much easier to find one of those motors in a boneyard near me, as I spend a lot of time in the yards around here, and cannot remember ever seeing a Fiero with a 6 in it. I rarely ever see any at all. Also, it was said earlier that the motor had trouble breathing at higher RPM's. Is that caused from using the 2.8 intake? or could it potentially be solved by creating a ram air setup?
No you need a Fiero 2.8 with coolent crossover pipe, all the intake pieces, injection rail and all etc. Basicly a complete engine. oh and a V6 fuel pump. try craigs list too, a Fiero 2.8 with a rod knock should be cheap. Ask on the forum too, someone has to of done a swap not too far from you and has a dead 2.8 they replaced with something else. Good luck on finding what you need.
Thanks for the help, luckily, someone at my work wats to buy the 4.5 that I was going to use. I just didn't realize that I was now going to have to buy Two motors. Oh well it just the price to pay. At least now I can stay with injection, which was why I changed my mind on the on the Cadillac motor. I really didn't want to go back to messing with a carb. This may be a stupid question, but this is my first Fiero, and I'm not trying to have any more surprises. are the cradles the same at least? I am really not trying to have any more surprises.
Hey, I just a 3.4 PR. Can I use the DIS system with the fiero timing cover, and crank pulley etc.? Reson is the crank sensor is mounted to the 3.4 timing cover, and I'm not sure if you can swap it over to the 2.8 timing cover.
Hey, I just a 3.4 PR. Can I use the DIS system with the fiero timing cover, and crank pulley etc.? Reson is the crank sensor is mounted to the 3.4 timing cover, and I'm not sure if you can swap it over to the 2.8 timing cover.
I don't know, that is more for the 7730 ECM swap thread.
When you say 2.8 stock parts I hope you mean the whole Fiero 2.8 engine assembly. As you need everything execpt the block, not just a few block parts, everything. Also your 86 4 has a different A/C compressor, won't fit the 2.8/3.4. So you would have to get a different A/C compressor too.
Actually, I found a complete interchange list, and there are a lot of other options for many of these parts, aside from the fiero. Most of these parts are very cheap at the pull it yourself yards too
'85-86 2.8L Upper This upper intake manifold (plenum) is unique. No interchange available. -------------------------------------------------------------------------------- '85-88 2.8L Center Buick Century '85 2.8L EFI, Center Buick Skylark '85 2.8L EFI, Center Camaro '85-89 2.8L Center Camaro '90-92 3.1L Center Chevy Celebrity '85-86 2.8L EFI, Center Chevy Citation '85 2.8L EFI, Center Firebird '85-89 2.8L Center Firebird '90-92 3.1L Center Olds Ciera '86 2.8L EFI, Center Pontiac Pontiac 6000 '85-86 2.8L EFI, Center
'85-88 2.8L: Equivalent distributors can be found in the following engines: Pontiac 6000 '85-89 2.8 L VIN W 8th digit Pontiac 6000 STE '86-88 2.8 L VIN W 8th digit Chevrolet Beretta '87-89 2.8 L VIN W 8th digit Camaro '85-89 2.8 L VIN S 8th digit Camaro '90-91 3.1 L VIN T 8th digit Camaro RS '92 3.1 L VIN T 8th digit Cavalier '85-89 2.8 L VIN W 8th digit Cavalier Z24 '86-89 2.8 L VIN W 8th digit Chevy Celebrity '85-89 2.8 L VIN W 8th digit Olds Ciera Cruiser '86 2.8 L VIN W 8th digit Cadillac Cimarron '85-87 2.8 L VIN W 8th digit Chevy Citation II '85 2.8 L VIN W 8th digit Chevy Corsica '87-89 2.8 L VIN W 8th digit Olds Cutlass Olds Ciera '86 2.8 L VIN W 8th digit Fierenza '85-86 2.8 L VIN W 8th digit Firebird '85-89 2.8 L VIN S 8th digit Firebird '90-92 3.1 L VIN T 8th digit Firebird Trans Am '87-88 2.8 L VIN S 8th digit Pontiac Grand Prix '88-89 2.8 L VIN W 8th digit Buick Skylark '85 2.8 L VIN W 8th digit Pontiac Tempest '87-89 2.8 L VIN W 8th digit
The exhaust manifolds in the 2.5L Fiero are found in several other GM cars but the manifolds in the 2.8L Fiero are unique. Unfortunately the 2.8L manifolds are prone to cracking and leakage. Repair by welding or replacement with used exhaust manifolds are the only options with a 2.8L engine (other than aftermarket performance headers or exhaust pipe modifications). If you are willing to make customized exhaust piping, manifolds from many 2.8/3.1/3.4 engine will bolt to the Fiero heads. Note that the Fiero manifolds are stainless steel.
That said, there is one set of cast iron exhaust manifolds that will bolt to the 2.8L Fiero which requires only minor modification to the downstream exhaust piping. These are the manifolds from the 1989/90 Grand Prix Turbo (Turbo ONLY). The Fiero Y-pipe requires bending to match the manifolds and this can be done using a vice and a 2" pipe for additional leverage. A benefit of using the Grand Prix manifolds is reduced noise in the cockpit.
NOTE 2: New engine mounts are appropriate when replacing an engine. The 1988 mounts can be expensive. Robert Lachance advises that you can use the front engine mount from a early '90s Pontiac Transport 3.8 (non-supercharged) on a 1988 2.8L Fiero engine for about $100 less than the Fiero-specific mount from parts stores. No modification is required. We don't have the part number at this time but Robert reports the mount is available from GM dealers. If anyone can provide the part number, please let us know.
Some parts are Fiero spacific, but more of them are not. I just posted this to give an idea, if anyone needs this information, it is readily available at fierosails.com. here is a direct link to the interchance page http://www.fierosails.com/PartsManual.html
I have almost completed piecing together a 3.4 for install in place of my duke, and I have kept my budget under 800.00 Aside from the 275.00 that I spent on the 3.4, the most expensive part was the engine harness, at 5.00 per foot, let me tell you, those things are longer than they look, when they start measuring them
I realize that this is not a great way of doing this, but my car needs a motor, or I will be walking by decmber, january at the latest, I thought about just putting another duke in it, but that would be from a junkyard too at this point, and the duke is a sorry a$$ motor to start with. At least this way I am putting in a motor (pulled from a wrecked 68000 mile car) that if it was abused, can stand up to it much better than an iron puke that I could pull out of a citation or lumina. anyway, I didn't want to piss anyone off, just wanted to put it out there that there are options not everything has to originate from a fiero
the CRANK sensor is Not on the Timing cover (thats the Cam sensor), The CRANK sensor is in the side of the block above the Pan Rail on the passenger side of the block. thats the only one needed for the DIS swap. there is a complete, VERY Complete,step by step w/ pics thread on this ( about a month ago I think) do a search.
Sardonyx247 how's the turbo running? Ever have it dynoed or do you know what your putting down? And thanks for the great thread.
------------------ Say no to socialism communism marksism maoism and say yes to Freedom! God Bless America! 1986 black gt fast back 4 spd recently rescued. 1987 gt fastback 5 speed! Hopefully swapped before end of summer.
Alright now that im in the right area ill be starting my swap aswell. First things first. Cam is going to be changed and a comp cam is going in. What do you think will be a good replacement kit keeping in mind that fuel economy is something id like to keep reasonable but making power a nice increase. I should be picking up my 3.4 next friday and can't wait to start dropping the beat up 2.8 . How well should the muncie 4 speed handle the 3.4's power? And which clutch?
Alright now that im in the right area ill be starting my swap aswell. First things first. Cam is going to be changed and a comp cam is going in. What do you think will be a good replacement kit keeping in mind that fuel economy is something id like to keep reasonable but making power a nice increase. I should be picking up my 3.4 next friday and can't wait to start dropping the beat up 2.8 . How well should the muncie 4 speed handle the 3.4's power? And which clutch?
Since I havent tried any different cams I can't offer any advice on that. But the stock trans and clutch should be fine. I didn't start breaking trans untill I boosted it. The biggest thing is to have a GOOD dogbone and firewall side trans mount.
Sweet I got my engine and currently have it in pieces. The cam is toasted on the engine from rust and worn down alot so I need to find someone that has put a performance cam in their 3.4 pr . Besides that it looks to be a good block but it will only tell once its been tanked and mic the walls. Hopefully I will start getting some more funds to start putting it together as I miss my fiero badly
Just wanted to say thank you. Your thread helped me tremendously. I now have my 3.4L from a 94 Firebird in the Fiero. It just passed smog yesterday and got registered again. One more Fiero back on the road! Thank you!
Just wanted to say thank you. Your thread helped me tremendously. I now have my 3.4L from a 94 Firebird in the Fiero. It just passed smog yesterday and got registered again. One more Fiero back on the road! Thank you!
(edit) dang over 36,000 views too.
