3.1l performance upgrade-what should i do/which one?

[no_doz]

im getting some money here soon & im trying to figure out what i should do with the motor in my 92 3.1l pontiac firebird with a 4 speed AT tranny. here are the options that im looking over, im just curious which one/ones will be the most bang for my buck (only a couple hundred $$, none of this $1500 supercharger kit junk, i cant afford that crap) & possibly suggest any i missed.

A. High Comp Pistons & .60 over bore
B. Performance Cams (not sure what model-any suggestions?)
C. Performance Intake Manifold- (once again, any suggestions?)
D. Bigger TB
E. Stroker Crank (cant find one??)
F. Underdrive Pulley Kit
G. Headers

im also considering swapping the topend off of a 91 lumina Euro 3.1l onto the block & having someone install the ecu, but im not sure how much that would cost/how hard it would be to swap all of that on & setup the ECU properly. any ideas on these or on anything else that would help, let me know.

[sharkey]

basicly for a few hundred bucks, throw a comp cams 260h2 cam kit in. a few other good ideas are the magnum roller rockers from comp cams, underdrive pulley, and headers. overboring to .060 isnt gonna net you much, and there are no higher compression pistons for the 3.1l ironhead without running compression so high that you will have to run race gas.

[geoffinbc]

Headers and a cam are the best bang for the buck. If you can do the work then you will be spending at least a couple hundred on each mod.

[El_Diablo]

out of those, if i could only pick two, i would go for the cam and headers.... do you already have a "header back" exhaust on the car?

[no_doz]

i dont have anything worth of an exhaust on the car, i just removed it at the cat, saved the pipe & have it modded to go straight out instead of curve over into the muffler, but its not connected so right now it just goes to a cat. would cams & headers help at all with the speed, because right now the car is slow as hell, not nearly as fast as my old 90 3.1 luminas with aluminum heads.

[El_Diablo]

i would do a 2.25 or 2.5 full exhaust with headers and a cam.... yeah, just about anything that increases power or drops weight will help you go faster

[project60degree]

depending on how much ur lookin to spend you can get custom pistons made from anywhere from 60-100 bucks a piece to whatever bore or compression you want. normally any engine shop can have it done

[XLR8ING]

A couple things, just based off what you've already mentioned.
If you're considering using the top end and ECM off a a FWD aluminum head 3.1, consider this instead.
Get the heads and intake off a 2000+ 3400 engine. They're better flowing than the older aluminum heads, and relatively cheap now.

Now, the 3.1 Firebirds have a regular old distributor, and I don't think the FWD intakes allow the use of a distributor. The intake would be turned 180 degrees compared to the FWD though, so it might just work. I know somebody on here will know for sure.
If so, you'll need the DIS unit, ECM and distributor plug/oil pump drive from the FWD set up. But to run the DIS unit, you'll need the crank position sensor that goes through the side of the block to send the crank trigger to the DIS. Again, I don't know if the Firebird has the provisions for the crank sensor, and if not, that's likely your biggest hurdle.

Besides the better flow, the heads and intake can save you some money on custom pistons.
When using aluminum heads with pistons intended for the iron head 3.1, you end up with compression over 11:1.
I would still suggest boring the engine a little and getting newer hypereutectic pistions (Sealed Power H562CP), but that's cheap compared to custom.
As far as I know, I was the first guy to use these pistons with the aluminum heads, and I also have a 260 Crane cam, and it was a great torque engine. Many people have done this head/piston combo since, and it seems to work great.
All this would be relatively cheap as well, since everything is available used, except the pistons.
As for cam, the Crane 260 has been a good cam for me, but there are others out there, so get some opinions on what's best for what you're wanting.
Good Luck!

[torq455]

Franz. Watcha think about the H272 on my 94Z 3400 top swap with auto tranny, heders, 62mm TB, etc? Wouldn't that get better power? From what I hear on a mostly stock 3.1 it's got tremdous midrange torque and top end power. What do you think?

[torq455]

oops! Might help to remind it's a 3400 hybrid....

[Syn]

torq455 looks like we're running identical setups almost
except i got the snail & bigger t/b

seriously man if your gonna put the money into a 3.1 look for a 350 tpi they can be had for like 3-400. your cam and lifters will run you 300.

if my firebird had a v6 i'd sell it, but it has a v8

[XLR8ING]

I looked at one of the bigger Crane cams years ago, but I forget which one it was. Likely the 272 though. Anyways, the reason I didn't get it was because of Desktop Dyno 2K.
I put everything in EXACTLY as I could for my set up, and it showed good increases, but when I compared to the 260, it only started getting better after 6000 rpm. Since I already had the 260 cam, I didn't bother.
Now this is on the Desktop 2k, and I've never heard what it's like in the real world, so take it for what it's worth.
But considering the better breathing of a 3400 heads vs. a 3.1, it would make sense that it would work.
Dumb question, but you are running a the Gen II block in the Z24 I assume, with 3400 heads? Sorry if you've mentioned it before, my memory sucks!
And Syn, you're likely right. For the price, a 350 swap would be more "bang for the buck".

[torq455]

[quote="Syn"]torq455 looks like we're running identical setups almost
except i got the snail & bigger t/b Well...will be running. It'll be another several months until money allows.

seriously man if your gonna put the money into a 3.1 look for a 350 tpi they can be had for like 3-400. your cam and lifters will run you 300.
And then convert to a RWD? How's that cheaper, not to mention the same amount of work? Kinda want to keep the 3.1 and kick some Cobalt SS and SRT-4 ass.

[Syn]

[quote="torq455"]

torq455 looks like we're running identical setups almost
except i got the snail & bigger t/b Well...will be running. It'll be another several months until money allows.

seriously man if your gonna put the money into a 3.1 look for a 350 tpi they can be had for like 3-400. your cam and lifters will run you 300.
And then convert to a RWD? How's that cheaper, not to mention the same amount of work? Kinda want to keep the 3.1 and kick some Cobalt SS and SRT-4 ass.

i was talking to the orig poster since he has a firebird, a v8 swap wouldn't be that much work and that much since tpi engines are cheaper then the lt1/ls1's

edit. cobalt/ redlines/srt-4's are fun to mess with when i was only running 6psi in my saturn, should be good for high 13's in the spring on street tires amd 10-12psi maybe better since i am doing some more work to it thats only a 1.9

i'm looking to kill ls1's with my cav

[torq455]

haha, I have desktop 2K too. I have the head air flow file inserted. It likes the bigger cam. It REALLY likes the roller set up. Yes Franz, Gen II block 3400 top end. maybe even the 70mm TB? I just don't want to go over 6500 RPM.