3800 Replacing a 3100 with a 3400...

[imported_Theautoguy]

Does anyone know if they are physically the same and if there are any sensor computer gremlins that may pop up as a result?

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[phat_ridegt]

is the 3100sfi or mpi?

the 3100sfi to 3400 sfi is a good swap, and doesnt take much modifications at all. i had a gagt that i was planning on doing this, but i ran out of motivation....heres a good site about it
http://www.3400swap.com/

 

[Turbocharged400sbc]

Does anyone know if they are physically the same and if there are any sensor computer gremlins that may pop up as a result? [/b]

i got this one down pat lol



the 3100 and 3400 (and many 3x00 60* V6 engines are virtually the same except for the crank/rods for the most part.



you didnt say what kind of car...

i assume your talking about the 3100's bigger brother the 3400 OHV V6 and not the 3.4L DOHC

the 94 will probably have a gauge temp sensor in the rear head by the brake booster (corner of head near Xover) but the later cars used the PCM to send the signal to the cluster so you will want to at the least install an aftermarket temp gauge or drill and tap a new hole near the T stat to use the gauge...



everything else will swap over no problem but i would say there may be issues since the 94 is a non MAF PCM and the 96+ are MAF equipped and may find running the bigger engine a bit difficult with the lack of tuneability i bet it'll run but it may not run well



the best option is to use the OBD2 harness and PCM to retain the MAF etc.

 

[imported_Theautoguy]

Thanks for the input, I'll pass this on to the guys doing it.

They're replacing a 3100 sfi in a 94 Grand Prix with a 3400 sfi motor from a newer car.