engine swap

[tukker]

has anyone ever swapped a 2.8 for a 3.1 from a cavalier in a 90 beretta gt?

[cshults]

It's been done many times. You can swap a few different motors into your car without much problems. The most popular swap these days is dropping in a newer 3400 engine. If you need a new motor and want more power you might want to consider this swap. Check out bstuff.com and do some searches on these swaps.

[tukker]

the only thing I am really worried about is the wiring and computer ya know?

[cshults]

Originally Posted by tukker

the only thing I am really worried about is the wiring and computer ya know?

I hear ya. The swaps are becoming more and more common. If you're in need of a new engine though I would really look into putting the 3400 in, there isn't really much of a performance increase from the 2.8 to the 3.1, maybe 10hp?? But if you go to a 3400 you're looking at a 50hp increase I believe. If you're not after performance, a 3.1 will be fine. I don't know the details of the 3400 swap, just know that a lot of guys are doing them in their Beretta's and from what I've read, it isn't all that complicated as long as you're ripping your old engine out anyways.

[tukker]

I got a question about the computer. The 3.1 came out of a cavalier z24 Automatic. I am putting it in a beretta gt manual so I am not using the auto tranny. Do I still need to swap the manual computer out? Any ideas?

[Decipha]

you shouldn't the ecu is for the engine not the trany

[richtazz]

The 90-94 Vin-T 3.1 is externally the same, and the 88-90 Beretta 2.8 uses the same sensors, so it should be a direct swap. The 94-up Vin-J and Vin-M 3100's are much different, and the swap woudl be more trouble than it's worth. Stay with the ECM for the Beretta, as the Cavi's ECM is set up for an automatic, so it has provisions for torque converter lockup points, as well as the auto's VSS signal, which are different than the Beretta's manual trans programming.

[poptones]

Are you talking about swapping in the 3400dohc motor, or a bigger version of the 3100?

If my beretta ends up needing a new spark controller I will be replacing the computer with a megaspark unit, so the ecu is not an issue. but would the beretta's auto trans handle the extra power?

And what about fuel economy? Yes, I actually care about that

[richtazz]

This thread is getting a little convoluted. The original poster (Tukker, welcome to AF BTW) wants to put a 3.1 out of a Cavalier automatic (91-94 Vin-T I would guess) into a 90 Beretta that originally had a 2.8 and a 5-speed. This should be a direct swap, as the Beretta's sensors are the same as the Cavi's. He should re-use the ECM from the Beretta, as the Cavi's is not programmed properly for his Beretta's manual trans. The 94-up 3100 and the 96-up 3400 use two crank sensors, use different heads and upper plenums, and would make for a much more involved swap that the ends (small power gains) would not justify the expense and fabrication involved to make it work. The 96-up motors are from OBD-II, where some of the 94-95's are a hybrid, and the early 94-back's are OBD-I, causing more headaches switching sensors and such. Decephia is mistaken, in that the ECU only involves engine controls. It also uses sensor input from the transmission (VSS, TCC, etc...) so you'll need one for a manual trans (re-use the Beretta's). Finally, to answer poptones (welcome to AF too), the Beretta's trans would have no problem handling the extra power, and fuel economy should remain virtually the same.

[tukker]

so i can use the manual tranny from the 2.8 on the 3.1? (just switching blocks) the tranny would hold up?

[richtazz]

Yes, the tranny will hold up, you'll also need the manual flywheel (obviously) from the Beretta's engine.