3.4L RWD Topend Swap

[Firehawk94]

I hate to bring this up cause I know you guys get tired of the same questions over and over again, but I have a 3.4l that came out of a Firebird and it needs to be rebuilt. Now, I want to install a 3400 topend on this thing and I want to know if this is the right route to go. You guys voice your opinion. Once I rebuild this engine I want to retire the 3.4 thats in my bird now,and swap it with this hybrid motor once its built. The engine in the bird has 243000 mi. right now and is still running like a champ, but for how long i dont know. Thanks in advance for any help yall provide.

I also saw that there was a thread back in Feb. of this year with ForcedFirebird mentioning a write up on this very thing, but i cannot find it. Was this ever made? If so it would help me alot.


Heres the car the engine will be going in:
1994 Pontiac Firebird
L32 3.4L V6
4L60E

[bszopi]

No, it has not been made yet (to the best of my knowledge).

Yes, it is definately worth it!!

I am currently in the preliminary stages of creating a new website that will be dedicated to 3x00 swaps, including hybrid swaps like you are talking about. Hopefully everything anyone will ever need will be covered on that site, including guides to walk people through every step and every part required for the swap.

[Firehawk94]

Very Nice!! Please let us know when this site is completed. I will support it in any way possible!

[Firehawk94]

Ok, Ive done some research on this swap and Ive come to the conclusion that i want to go with 3400 topend...reason being my local junkyards dont have many "newer" vehicles equipped with the 3500. So, with that said Ive worked up a part list, let me know if Im missing anything:

3400

1. UIM/LIM including throttle body and all associated sensors
2. Heads
3. Fuel injectors/Fuel Rail
4. Pistons

I almost KNOW I am forgeting something so guys feel free to chime in. Also I have a question concerning the ECM/wiring harness. Is the 3400 topend swap compatible with the existing wiring harness/ECM on my 94 Camaro? Or will I have to snag the harness and ECM from the donor motor? Please help me out with this guys I want to get the ball rolling on this project asap as I already have the motor out and Im about to begin the teardown this weekend.....Thanks!

[robertisaar]

since its a 94, i would say that it has the digital EGR, whereas the 3400 topend is the linear(?) so you would need an adapter for that...

[Firehawk94]

since its a 94, i would say that it has the digital EGR, whereas the 3400 topend is the linear(?) so you would need an adapter for that...

By linear I am assuming that you mean "nonelectronic" Could you please clarify? I do however have the electronic EGR if that is the correct term for it. If I do require an adapter, are they readily available? Thanks for your feedback!!

[robertisaar]

digital in this case meaning there are 3 solenoids, 1 lo flow, 1 med, i hi.

they can only be completely on or completely off, but you can have any combination of the 3, depending on engine load.

the linear one, which is used on all obd2 vehicles, i think, is more of a % based idea: 1 valve that can open or close as far as its told.

and there are adaptors in the WOT-Tech Store.

[Firehawk94]

Oh ok, now this is making sense. So yea with my car being a 94 that means it would actually have the digital egr meaning I will need the adapter. Thanks for the heads up! Also, would the existing ECM and wiring harness in my Camaro be compliant with the 3400 swap? Sorry for the questions Im just working on a "grocery" list for this weekend.

[robertisaar]

there are a few people running obd1.5 with a 3400 with decent results. your motor came with a MAF sensor didn't it? if so, then your fueling shouldn't be so bad, but spark would concern me.

anybody happen to know what the RWD3.4's ran for spark advance?

i'm thinking since it had the old iron heads, its probably WAY too much spark for the new 3400 aluminum heads. i could be wrong, but i'm sure somebody on here has some idea.

if you had a manual tranny, then i could see if i could convert it to OBD1, that way you could actually tune it, but you have the 4l60e, which i'm NOT confident in saying, could be a controlled by a 16149396....

[Firehawk94]

No, it does not have a MAF sensor it only uses a map sensor along with the tps as well as a vacuum operated FPR to keep the fuel under wraps.

As for the tranny it is in deed the dreaded 4l60E I absolutely hate this transmission they are totally vulnerable in stock form (meaning they are weak). Ive been through 3 in 2 different cars luckily this one is still ok, but yes to answer your question i do have the 4l60E. Now, on another note...in 93 the 3.4L equipped Fbodies actually utilized the th200r tranny which is not computer controlled before they came out with computer controlled 4l60 in 94. Maybe I could do something with the ECM and wiring harness out of a 93 Fbody? Which would mean I would have to ditch the 4l60 thats in the camaro now for the earlier 200r which wouldnt be a problem as these are easily had at any junkyard(they ran these things in the 3rd gen fbodies as well) But I could just be spinning my wheels with this idea and there is probably a simpler way around this ecm/wiring harness deal with the 3400 topend swap. I really am planning on doing this swap guys and yall are NOT wasting your time on this thread I just need to take in some info so I get this right on the FIRST time. Thanks guys!!

[robertisaar]

forcedfirebird (john) found out that the 93 f-body PCM is a flash-only model. he was working up something recently, you might want to contact him about it, he's been around.

as for the tranny, yeah i know about the third-gen deal, i had a 85 iroc-z28 with the tpi305 for a little while...

[ForcedFirebird]

The 3rd gen transmission is actually a 700r4, the 1993 had a 4l60 (non-e) and is the same as the 700r4 with the exception of some case changes.

I actually haven't been able to even work on the ECM at all, 22 days of straight rain here, and the test car is outside

All of the OBD1 and OBD1.5 f-bodies are speed density (MAP) based ECM's.

I am hoping to eventually have a piggyback 94-95 swap completed in the near future.

If you are going to use the 3400 top end, you will need to swap to the pistons out to avoid extremely high compression for pump gas.

Sorry I haven't gotten the write-up done, but this car is the one I am using to do so, and has an order of operations. I already did all the rear suspension modifications, changed the fuel pump and exhaust, next is the ECM swap so I can grasp the tune/function on a known good running engine (to make sure all is functioning properly), then I will be moving on to the k member swap. While the engine is out during the k member swap, I will show all details of the hybrid build for the f-bodies

[robertisaar]

All of the OBD1 and OBD1.5 f-bodies are speed density (MAP) based ECM's.

I am hoping to eventually have a piggyback 94-95 swap completed in the near future.

i could have swore someone was trying to tell me they had MAFs.... oh well, not important.

and something i noticed: its taken 14-15 years to figure out how to get the94-95 vehicles tuned? i think if thats what GM intended(us not messing with them anyway), they put up a hell of a fight, but we won... or at least are getting close to winning...

[IsaacHayes]

94-95 are same boat as us 3100'ers with the OBD1."5". Iron heads do run a TON of timing since they are not fast burn heads. If running 3400 pistons you will have "stock" compression but still the extra timing and the fuel being off would make me want to swap to an ECM to tune.

They have the same ECM as the 3100 OBD1."5" cars. I don't know if you could swap the 3100 cars ECM and have it control the auto trans the same or not??? It's an idea. No idea what the gear ratios are so the shift points might be whack. The tuning would be pretty close (same as a 3100 to 3400 swap). In a manual car that might be a good quick idea to try.

Or you can megasquirt and go to the older non electronic trans, or go to OBD1, or OBD2.

[robertisaar]

Iron heads do run a TON of timing since they are not fast burn heads

thanks for the confirmation about that isaac...

maybe keep the existing PCM to control the tranny, and run a 16149396 for fuel/spark?