quote Originally posted by McCool: 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.

quote 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.

quote 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).]

Some more :

Cool, thanks for that little lesson.

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,

quote Originally posted by McCool: Cool, thanks for that little lesson. 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.


------------------
"DRIVE IT LIKE A FIERO"
'84 Fiero, engine to be determined
'87Blue GT 3.4L Swap Completed!!!!!!!! Boosted!!!!!!!
Las Vegas Fiero Club
Fiero Road Club Of Northern Nevada

[This message has been edited by sardonyx247 (edited 08-02-2008).]

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

quote Originally posted by McCool: 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.

------------------
"DRIVE IT LIKE A FIERO"
'84 Fiero, engine to be determined
'87Blue GT 3.4L Swap Completed!!!!!!!! Boosted!!!!!!!
Las Vegas Fiero Club
Fiero Road Club Of Northern Nevada

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)/

hey sardonyx247 i know you have a 3.4l turbo what do you think about this?
https://www.fiero.nl/forum/Forum2/HTML/095416.html

[This message has been edited by 3.6lvvt6spdgt (edited 10-09-2008).]

I have to thank you again. I'm back to a 3.4 install.

Thanks again!

[This message has been edited by Saxman (edited 10-25-2008).]

quote Originally posted by 3.6lvvt6spdgt: hey sardonyx247 i know you have a 3.4l turbo what do you think about this? https://www.fiero.nl/forum/Forum2/HTML/095416.html

I wrote my own code, no need for yours. Beside my engine is vastly different than yours.

quote Originally posted by my-fiero: Some more :

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MY-FIERO ---- WHERE DID YOU GET THE CV AXLES? Did you get both sides? and how much if you don't mind me asking?


Are they refurbished or new?

[This message has been edited by unboundmo (edited 01-27-2009).]