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87 V6 swap into 85 GT, any issues? by JCUOIT
Started on: 02-10-2008 01:59 PM
Replies: 11
Last post by: iamtylerdurden on 04-26-2008 08:21 PM
JCUOIT
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Report this Post02-10-2008 01:59 PM Click Here to See the Profile for JCUOITSend a Private Message to JCUOITDirect Link to This Post
quick question that my room mate has about his car and the swap he's about to do:

he has an 87 v6 and 5spd that he wants to put into his 85 v6 4spd. he wants to keep his 4 spd and only wants to swap over the V6. what needs to be done? are there any differences in the ECMs? wires? plugs? any problems with just plug and play? note: the 87 had A/C and his 85 does not? will that make any difference? any wiring or programing differences for the AC?

Thanks
JC

[This message has been edited by JCUOIT (edited 02-10-2008).]

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JCUOIT
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Report this Post02-10-2008 10:59 PM Click Here to See the Profile for JCUOITSend a Private Message to JCUOITDirect Link to This Post
BUMP FOR JT, need info!

thanks
JC
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Report this Post02-10-2008 11:10 PM Click Here to See the Profile for topher_timeClick Here to Email topher_timeSend a Private Message to topher_timeDirect Link to This Post
Does he want A/C in his 85? He should be able to just bolt the engine in without much trouble. He will have to use the clutch parts for the 4 spd, though. He will also need to use the harness and ecm from the 85, as well.

[This message has been edited by topher_time (edited 02-10-2008).]

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JTUOIT
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Report this Post02-10-2008 11:48 PM Click Here to See the Profile for JTUOITClick Here to Email JTUOITSend a Private Message to JTUOITDirect Link to This Post
 
quote
Originally posted by topher_time:

Does he want A/C in his 85? He should be able to just bolt the engine in without much trouble. He will have to use the clutch parts for the 4 spd, though. He will also need to use the harness and ecm from the 85, as well.




Hey,
Thanks, sorry i was away from my computer for a while taking care of some school stuff. Thanks JC (my roommate) for posting this up for me...

I have a cradle setup from an 87 (engine, trans, axles, hubs, suspension, harness, ecm etc.) that came with AC and the 5spd (AC pump taken off)... I'll be keeping the 5spd either for another car, for a later project on the 85, or sell it off... The 85 does not have AC (Which I didn't want/need either way)...

So use everything from the flywheel back from the 85... use the 85 ecm... is the connector to the trans the same for the 4spd and the 5 spd? or will i have to splice in the 4spd connector?

Thanks a bunch,

John
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JCUOIT
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Report this Post02-11-2008 12:37 AM Click Here to See the Profile for JCUOITSend a Private Message to JCUOITDirect Link to This Post
i call dibs on your 87 slave cylinder!

JC
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Report this Post02-11-2008 09:00 AM Click Here to See the Profile for JazzManClick Here to Email JazzManSend a Private Message to JazzManDirect Link to This Post
The '85 uses a different shifter and shift cable set, plus there are different hangars on the end of the cylinder head to keep the cables away from the exhaust, etc. The 4-spd uses a reverse switch in the shifter, the 5 spd (Getrag, right?) uses a switch in the transmission so the engine wiring harness is slightly different. The flywheels are the same, the only flywheel change was for the '88 models which went to an internally balanced crank design.

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JTUOIT
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Report this Post02-11-2008 11:08 AM Click Here to See the Profile for JTUOITClick Here to Email JTUOITSend a Private Message to JTUOITDirect Link to This Post
*edited* - swapping entire cradle rather than just the motor.

I'll be keeping the 4spd in the car, so i am already planning on keeping the flywheel, clutch, pressure plate, t/o, etc. in tact... the hardware part of the swap is already prepared for, I just don't want to go hunting around for a random wire, clip, or plug in a few weeks when something electrical doesn't work...

is the VSS plug different from the 4spd to the 5spd getrag (would i just splice in the 4spd plug into the 87 harness)? Are the harnesses any different between the 85 and 87 (sans vss plug)? If possible, i would rather use the 87 harness as the 85 harness has had some wear, clips and loom are very brittle, etc

[This message has been edited by JTUOIT (edited 04-26-2008).]

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JTUOIT
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Report this Post04-26-2008 02:00 PM Click Here to See the Profile for JTUOITClick Here to Email JTUOITSend a Private Message to JTUOITDirect Link to This Post
Hey guys, an update/couple questions on the install.

I ended up going with the 5 speed instead of the 6 speed.

Both the clutch slave (from the 4 speed) and the slave mount (from the 5 speed) are threaded. Should I remove the threads on the slave cylinder and send the bolts through the slave to the mount, or vice versa? Or should I pick up a new slave?

What modifications need to be done to the shifter box (4 speed Muncie to 5 speed Getrag)

Where would the best place to place an additional braided ground, to and from?
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82-T/A [At Work]
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Report this Post04-26-2008 02:24 PM Click Here to See the Profile for 82-T/A [At Work]Send a Private Message to 82-T/A [At Work]Direct Link to This Post
If basically, as I understand it, all you're doing is JUST swapping out the long block, then you don't need to do anything special. The long block from an 85 is esentially 100% the same as a long block from an 87. The ONLY difference that I can see is that the intake plenum on the 87 has "FIERO" engraved.

If you plan to use the 4-Speed and the ecm and all the wiring and everything from the 85, and all you're doing is just swapping out the motor, then just keep everything from the 85 and JUST swap out the motor.

The 85 ECM is actually a superior ECM. The differences are very minute, but from what I understand, the timing and fuel mapping are ever so slightly more aggressive in the 85 as apposed to the 87.

The 85 4-Speed is only a 3.65:1 final drive, and while that is good... if you're planning on making this a good car that you can drive (in the year 2008), I would highly recommend the 5-Speed.

------------------
Todd,
2006 Pontiac Solstice
2004 Volkswagen Beetle Convertible (Wife's Car)
2002 Ford Crown Victoria LX
1987 Pontiac Fiero SE / V6 (3.2) 5-Speed
1984 Porsche 944 5-Speed
1981 Pontiac TransAm (Olds 455BB)
1973 Volkswagen Type-2 Transporter

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JTUOIT
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Report this Post04-26-2008 07:15 PM Click Here to See the Profile for JTUOITClick Here to Email JTUOITSend a Private Message to JTUOITDirect Link to This Post
 
quote
Originally posted by 82-T/A [At Work]:

If basically, as I understand it, all you're doing is JUST swapping out the long block, then you don't need to do anything special. The long block from an 85 is esentially 100% the same as a long block from an 87. The ONLY difference that I can see is that the intake plenum on the 87 has "FIERO" engraved.

If you plan to use the 4-Speed and the ecm and all the wiring and everything from the 85, and all you're doing is just swapping out the motor, then just keep everything from the 85 and JUST swap out the motor.

The 85 ECM is actually a superior ECM. The differences are very minute, but from what I understand, the timing and fuel mapping are ever so slightly more aggressive in the 85 as apposed to the 87.

The 85 4-Speed is only a 3.65:1 final drive, and while that is good... if you're planning on making this a good car that you can drive (in the year 2008), I would highly recommend the 5-Speed.


Thanks for the reply.

I am essentially swapping over engine/transmission/cradle etc. from an 87 car into my 85 car. The cradle is bolted in, only steps to finish off is the clutch slave, shifter box, and . The slave from the 4spd (my car's original slave cylinder) lines up with the mount (on the 5 speed trans), but both the slave and mount are threaded. The

About the ECU, I believe the plugs match up, however, would this cause an issue with the reverse light? (switch being in the trans case, as opposed to the shifter box)
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Indiana_resto_guy
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Report this Post04-26-2008 07:30 PM Click Here to See the Profile for Indiana_resto_guyClick Here to Email Indiana_resto_guySend a Private Message to Indiana_resto_guyDirect Link to This Post
 
quote
Originally posted by JTUOIT:

About the ECU, I believe the plugs match up, however, would this cause an issue with the reverse light? (switch being in the trans case, as opposed to the shifter box)


You will need to wire in the reverse light switch from the interior pigtail to the tranny switch as I recall. No big deal. I cannot rember if changing the engine harness is a plug and play,
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iamtylerdurden
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Report this Post04-26-2008 08:21 PM Click Here to See the Profile for iamtylerdurdenClick Here to Email iamtylerdurdenSend a Private Message to iamtylerdurdenDirect Link to This Post
i've got an 85 GT. I swapped in an 87 V6 that i bought used. Altogether I...:Used the 87 cradle, got rid of the auto that was on the engine and put my 4 spd on, got new trans and engine mounts, used the 87 wiring harness and used my stock 85 computer on 87 octane even with all the mods i did below. If you have any trouble PM me. I'm sure i can remember what i did.

------------------
Black/ Silver 85' GT
Rebilt 87' engine
Bored .030 over block ~9.5-9.7 Compression
Probe Forged Pistons 440 Cam
ARP Rod Bolts Per. Valve Springs
Roller Timing Chain Blaster Coil
Flowmaster 80 Series CRX Intake
Bosch Plugs+ Wires 8" Subwoofer

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