3.4 fbody

[FlamespikeMST]

Hi everyone, new to the site. I own a 1995 firebird 3.4
Ive been looking in to at least attempting to make this go fast
because stock they honestly suck,anyways i have recently learned that you can take off the stock 3.4 series heads and they can be replaced with higher flowing aluminum heads from the 3100 and 3400 series engines
ive done a few mesurements since i will have to use the 3100 or 3400 series intake i would have maybe 1/8 of an inch cowl clearance, i see no problems with that, i also see i would run into a few problems like having to move the alternator and ignition paks slightly higher then usual, and quite possibly change to pistons to that of the 3100 or 3400 series to lower my compression since highest octane in these parts is 91.
can anyone else fill me in on other things i would tohelp prepare myself for one heck of a job im gonna get myself into?
exhaust manifolds, fuel issues, would i really have to swap pistons out,possible turbo possibilities in the future and any help with that would be most appreciated
if this topic was discussed to death, i apologize, can someone direct me to a faq page or something along that linoes of one..thank you

[geoffinbc]

If it were me I would go straight to the turbo and skip the aluminum heads. You can make a one or two hundred HP more with a proper turbo setup. Iron is better for durability which is what you need on a turbo car. The Aluminum heads will make a little more power but will just cost alot more money with all the work and parts you will need to address.

[SappySE107]

Boost on the gen 3 will net more gains than with iron heads unless you port the heads out a ton. Boost isn't gonna blow up the aluminum heads and the only way I see it making a difference there is if you are wanting to push a huge amount of boost. Russ did the swap you are talking about, so hopefully he will share what he has learned. I know tuning it will be a major factor because the iron heads want more spark advance.

If you tune it though, you can run that compression with the gas you have, as long as you put in a pretty wild cam (272 crane grind works).

[StudlyCamaro]

dont forget you will have to lengthen the throttle cable, the fuel lines will have to be modified, the numbers on the top of the plenum will have to be shaved off for the 1/8th of an inch clearance.

russell is the man, and will help you out a lot if you ask him his handle on AIM is Camwire and cryptowire

he has helped me out a lot with my plans (i havnt done the swap yet, however hopefully in the next year i will have my 3.4L/3400 hybrid running)

[SappySE107]

I wouldn't mind having a nice writeup on this hybrid to put on the site, so ill keep track of this thread. So you have to shave the numbers off the plenum to make it fit?

[FlamespikeMST]

Yes me and Russ are very good friends, but sadly he isnt on alot of the time, and me and him have confilcting schedules.
i didnt know about the longer throttle cable thats new.
shaving numbers is as well.
managment to the fuel lines, lol, not a problem
there is still the issue with the pistons, will i have to swap them out for sure?

and as for my want to do the aluminum head swap to turbo, well im not going to jump too far ahead of myself, i would like to do this aluminum head swap first and run with it awhile to work all the kinks out.

my main reason i would like to turbo charge it with alum heads is because i would like a larger baseline to start with, 200 horsepower is alot better to start with than 160, plus if i for certain have to change the pistons out, might as well drop some compression, and add a boost cam, i mean might as well right?
my goal is to is to run 8-10 psi safely on 91 octane..<is that undoable from a perspective point of view?>
my main goal on the track would be high to mid 13s
once again thank you for your speedy responses and all the help i have recieved thus far

-Shaun

P.s. If and when i start on this project, i will make a write up complete with pictures if you all are interested

[StudlyCamaro]

yeah , you will need a longer throttle cable because the throttle body linkage is on the oppisite side of the throttle body. or if modified the plenum to take the stock f-body TB.

as for the numbers on the plenum being ground down, that is just what russ had said before, and from the pics he has i believe it from the looks of em

the pistons will for sure need to be changed out if you are planning on running 8-10 PSI, with the stock 3.4L pistons and the alumnium heads your compression ratio will be in the 12's, and 12 CR with 8 PSI would for sure cause some serious detenoation unless you have an intercooler with over 100% effecincy

mid to high 13's would be easily possibly with a turbo and the alumnium heads, tiago's in the 13's with his ported iron heads and stock cam + boltons

[SappySE107]

You can use your current pistons until you decide to boost it though, but the only reason you couldn't do this is because of the stock cam and the tuning. I doubt the stock cam is wild enough for that compression, so it will cause issues. I guess it depends on how many times you wanna swap parts out, and how soon you can tune it.

[firechiken]

Isn't there an issue with push rod length?

[SappySE107]

Yup, the iron heads use equal length pushrods, and the aluminum heads dont (don't worry about the roller rocker gen 3 pushrods either, they wont fit). It will probably take custom length pushrods to do the setup 100%, though the flat tappet cam AL head pushrods might work ok.

[StudlyCamaro]

the flat tappet cam AL head pushrods might work ok.

thats what russell used

[TheProfessor]

Boost on the gen 3 will net more gains than with iron heads unless you port the heads out a ton.

i dont think iron heads can be ported out that much because of the two siamesed intake runners

[bszopi]

Check out Curtis's heads before you say they can't be ported out significantly...

[TheProfessor]

Cast iron V6/60 cylinder heads were designed for production applications, and extra material was not included in the port walls to allow extensive enlargement of the runners.

Quoted from chevrolet power

[oil pan 4]

got head?

Nope the runner walls arn't that thick.
Check my heads on my car domain site, there not super wildly ported by a mad man not afraid of a water jacket or any thing like that.
Just a nice street port. With a mirror bright combustion chamber fnish for high boost carbon detonation resistance (nothing will stick to my chamber walls hahahah!).
They can be hoged out some what. You can tare up the top of the port around the valve guide, that is the worst part of the casting and can be improved the most I think. You have materal there at least.
You can reshape the bowl of the intake port, it dosen't need to much shaping.
And that vane in the middle of the port, its over sized. It can be thined and reshaped. It Improves flow and helps mix A & F.
If there going on a 3.4L with a 3.62 bore you can widen the combustion chamber to the with of the cylinder head gasket, unshrouding the valves a good bit.
I wouldn't mess with the quinch pad to much.
To me a quinch pad is like wet lands, if you tare it up in one place you need to remake it some where else.
The gen II and up heads have a lot of quinch aera.
The LS1 heads have a figure 8 combustion chamber the thing is all most all quinch pad.
The gen 1 heads only have a little quinch pad behind the valves like a lot of SBC heads. I wouldn't go cutting into that to much.
The Exhaust ports arn't to bad, the valve guide can be cut higher into the port and runner it's self can all ways be made bigger the runner walls that make them are thicker than the intake ports.