Hi there.

I have a 1990 Firebird Base model 3.1 v6.

I'm sort of new to these forums, but I've read a lot on them. I just don't post. I don't have the knowledge to post.

When I do post it's usually for help in things I haven't been able to find myself. So please, if there is already a post that I need to be subjected to, let me know.

Here's what happenin'-

My dad found a 3.8L Supercharged V6 in a '98 Grand Prix at the junk yard a few weeks ago. He told me he wanted it for HIS Grand Prix, and made me do all the work to get it out. I was happy to do it. It came with a crushed pinky and a lot of scratches, but I love learning anything I can when it comes to a car.

Anyhow, the engine was completely burned to crap on one side, but the only thing that looked real damaged was the wiring and the valve cover (which I grabbed another one off some other 3.8 liter within 5 seconds of noticing that)

We got the engine for 75 bucks, supercharger and all. Dad says we can rebuild, no problem. Just need to clean it thoroughly, make sure it's usable, and repaint.

The day Christmas comes he says "Hey guess what, engine's yours"

That's when I started popping off questions to him. Figured I'd pop some off to you all and see what you have to say also.

First question : The engine came from a front wheel drive vehicle. Does anything have to be changed to make it work with a rear wheel drive vehicle instead? My dad says no, I'm just checking.

Second question : Do we need a new transmission? Or will the stock transmission from my 1990 base 3.1l V6 work? It's a 7004r, right?

Third question : My exhaust is currently messed up. Dad says I'll need something that's atleast 2 1/2 inches. I need something that's not super expensive. Ideas? Headers too. Wondering how this will all fit together.

If anyone knows how to do this, knows the problems I might encounter, or has a link to some sort of guide to do something like this, please let me know! I know you guys have helped others with their engine swaps and I really hope that I can get the same help. I know I'm no "Known" person on these boards, but I read them (Archives too) daily. I love this car more and more the more I read about what I can do to it!

Please, ideas!

And I know there was a Camaro/Firebird with this same Engine, if I DID need a tranny, would I just use that?

Thanks in advance guys. Sorry for the long post, I'm very detail oriented.

 

engine wont work because its a fwd block. theres an adaptor you can buy (i think) to mount the supercharger on a camaro 3.8

 

There's no way to convert that? :-\

 

IIRC, some people have done it, but it requires modification of the engine mounts. I've read some info here, but you'll have to learn how to search to find it though because I had about ten threads open at the time. lol

You might be able to get a 3.8 block out of a RWD vehicle and transfer everything over Could search for 3.8 swaps or something. If this is possible, that's what I would do.

Hope this helps.

 

It is possible to swap this engine, but there is a lot of work. I swaped 3,1 into RWD 3800 series II in my 1992 Firebird - so it is possible, but FWD 3800 engine needs also some modification of intake and ECM.
https://www.thirdgen.org/forums/pict...pictureid=1311

 

i dont see this working... :/ it was a nice gesture though i would just stick it in your dads car

 

This was a swap I had thought about doing when I still had my GTP, but there's a lot of fab work needed to get a FWD 3800 to fit in these cars. More than I felt comfortable with my limited welding skills. I'm choosing the slightly less intensive LSx route this time, but we'll see how that goes

 

The FWD 3800's use the same 60* bell housing pattern as your 3.1L.

The TTA that used the GN engine actualy used the FWD heads to help make it fit so the FWD engine should physicaly fit no problem.

I dont know if the FWD block retained the RWD mount pads.

The intake (blower inlet) will be sticking into the firewall.

The stock logs should fit fine, you'll need a custom Y pipe.

Most of your stock harness should work fine on the 3.8, infact if it were an NA 3.8 the stock harness and ECU could even run it with little to no work. A PROM from a similar year (to your own car) 3.8 vehicle would take care of the 3.8 specific calibration.

 

That's the kind of information I need. My dad's deadset on doing this no matter what. meaning I need all the information on doing it... I don't really have a choice whether or not it's going to happen.

So, I just want to make sure it goes right. Thanks for the information man, if you have any other information that would be awesome too....


like, will my tranny work with it, or do I need another one from say, a Camaro with a 3.8!? from later 90s

 

Bump!

 

Like I said the 3800 uses the same bell pattern as the 3100 and nearly all GM V6's and the early I4's.

The FWD block might not have htreades holes on some of the outer locations because the FWD trans will have been threaded (with the bolts going in the opposite direction) instead of the block. Using a nut and bolt in this case is a simple solution.

 

ok so im new to this camaro biz but not the swapping and changing and crazy **** i did some research on this little motor so the block is the same for the 3800 and the 1990 v6 the kids got which i have a 92 and in a similiar situation which im aiming for a more well rounded performance machine anyways the blocks are the same both the 60Degree v6 so would it be crazy to change the upper engine wilst keep the original block?? or could i rip the supercharger off the 3800 and slap it on the little 3.1L thats the question im pondering right now

 

The 3.8 is a 90 degree V6, it shares nothing with any of the 60degree V6's. The block, heads, intakes and everything else are completely different. The only thing that sometimes interchanges is the coil packs.


ls six, the FWD blocks are threaded the same as the RWD blocks. The bolts go through the trans and into the block like normal.

 

oh my bad i read it funny its just got the 60 degree bellhousing

 

Yep, same bellhousing. A few other engines use it as well like the LS4 and the N* V8's.

 

so normally i would jump for the v8 but EVERYBODY does that so unoriginal i want to something creative but trying to find the best setup would be i know if i turboed it it would be a nice power to weight ratio but its kinda difficult to find the crank rods piston exc for this motor on the other hand i want to do something WAY out there like hook up a jag motor to a TH400 tranny and go all out on modifications which i think would be badass a V12 Camaro???

 

look for my thread in the V6 section.. i'm doing something "different".. lol

 

I hope you're not banking on success because its original (its not). If you want a L67, fine go buy a Fiero, those cars love them and fit great. Have fun figuring out how to mount a FWD block to a RWD chassis (mounts are missing/moved). What are you going to do about the rear TB? Why turbo a SC engine? They dont seem to like it very well. Fiero guys gut the blower and run a big turbo, but generally their big numbers last a few runs and they buy a new trans or shortblock

Theres several very good reasons 3rd gen guys swap a big honkin EFI V8 in there. Its cheap(er), its proven, and it works very well. You can pretty much pull a LTx/LSx swap off with ONLY store bought items and zero fabrication

If you want a cheap quick boost in power, go with a 3.4 long block under your 3.1 externals. Maybe a few of the V6 forum mods

 

Hey have you done this yet and could you tell me what i will need for my 92 rs

 

Hey have you done this yet and would it be possible for you to give me a list of what i will need thank you

 

Not always true, the outer most bolt holes are not threaded like on the RWD blocks, the bolt goes in backwards through the engines bell flange and often threads onto the FWD trans bellhousing.

This in no way holds one back from doing a RWD swap. The upper bolt holes are un changed and iirc the dowls are unchanged. A nut and bolt for each outboard hole works just fine. Infact I see this setup all the time on many OE aplications.

But the FWD motors both 90 and 60* went through many minor changes throughout the decades, the 60* V6 in the G6 actualy has a slightly different bell pattern than the older blocks. Swapping the 6 speed into an older FWD GM requires a bit of improvising.