3.4 DOHC Rear Wheel Drive Swap

[jeepers24]

Ok I have been searching for quite a while and now I am gettting blurred vision and a headache. I am new to the sight but not new to 60* v6's, but all my applications have been FWD. Basically what I am doing is trying to find info about putting a 3.4 DOHC into a Jeep/Rockcrawler. I have seen info on this application into a Camaro but cannot find any detailed tech writeups for it. What info do I need to know? Already know I need a 60* 700r4, will the torque convertor bolt to the 3.4 flex plate? Wiring all OBD I? Anyone out there that can rework the computer/harness so it is a stand alone engine management system(no need to control non comp 700r4). Any other little tidbits of wisdom, possibly like don't do it? (Come on there's got be at least one of you.) By the way fabrication skills will not be a problem for all the mounts etc.. Thanks in advance.

[sharkey]

RE: 3.4 DOHC Rear Wheel Drive Swap

the 2.8l rwd flexplate will bolt right up to the 3.4l dohc crank, however you need to make sure the flex plate is for an internaly balanced motor (89+). you best bet for ecm would be to find a z34 5 speed car. they are obd1 and being 5 speed, there are no controlls for the tranny. the only thing you will be missing tranny wise is lockup, however its easy enough to put on a vacume switch, if you ever will be wanting it to function.

[Wolf]

RE: 3.4 DOHC Rear Wheel Drive Swap

I was gonna do it, but there isn't enugh room behind the motor in a 4th gen camaro(you cannot turn the stock lower intake around ) save those fab skills for headers,because the dohc will bolt to rwd motor mounts
shouldn't have to much trouble putting one in a thrid gen camaro /firebird

[sharkey]

RE: 3.4 DOHC Rear Wheel Drive Swap

the 3.4l dohc has the fwd lugs in the block for mounting. the rear mount (passenger side) will bolt right up from a rwd, however the front (drivers) mount wont.

[OS2Dust]

Both the mounts will fit, in the case of a 3rd gen camaro, however they do need to be modified slightly, a notch needs to be cut in the boxy 3rd gen motor mounts to clear the 2 knock sensors in a late model 3.4 DOHC, and only 2 of the 3 bolts on the one mount can be used unless you weld on a tab to use the 3rd one, however the 2 that are used are oriented like this : I got partially thru the swap in my 3rd gen camaro and it is currently still in "progress"

I know this isn't specific to your Jeep application but HTH

[RebelGT]

Re: RE: 3.4 DOHC Rear Wheel Drive Swap

I was gonna do it, but there isn't enugh room behind the motor in a 4th gen camaro(you cannot turn the stock lower intake around ) save those fab skills for headers,because the dohc will bolt to rwd motor mounts
shouldn't have to much trouble putting one in a thrid gen camaro /firebird

you could have waited for the fab'd intake manifolds that ben is working on


other then that, I wish I could help more, but my DOHC rwd app is totally different then yours...

[donk_316]

RE: Re: RE: 3.4 DOHC Rear Wheel Drive Swap

Also you dont need to use the 700r4....there is a STOCK jeep bellhousing that will bolt to the t5/ t4 also.

<----owns a cj7

[geoffinbc]

3.4L Sucks now. Get a 3.6L

[Guest]

Re: RE: 3.4 DOHC Rear Wheel Drive Swap

the 2.8l rwd flexplate will bolt right up to the 3.4l dohc crank, however you need to make sure the flex plate is for an internaly balanced motor (89+). you best bet for ecm would be to find a z34 5 speed car. they are obd1 and being 5 speed, there are no controlls for the tranny. the only thing you will be missing tranny wise is lockup, however its easy enough to put on a vacume switch, if you ever will be wanting it to function.

Just wanted to point out, internally balanced was '87+.

[sharkey]

RE: Re: RE: 3.4 DOHC Rear Wheel Drive Swap

actualy it wasnt. swapped the motor on my buddies 87 z24. it had a weight on the flex plate, the motor from the 89 grand prix didnt. the flex plate part number changed in 88 aswell. 88 they list both with or without weight, 89 they list only one.

i trust my first hand experiances more than what ive read.

[854x4s15]

keep researching there's a lot of information out there concerning this swap. Try s-series.org. It's S-10 site but there is alot of information concerning the 3.4L swap including wiring and tranny compatabilies. Good luck.

[Guest]

Re: RE: Re: RE: 3.4 DOHC Rear Wheel Drive Swap

actualy it wasnt. swapped the motor on my buddies 87 z24. it had a weight on the flex plate, the motor from the 89 grand prix didnt. the flex plate part number changed in 88 aswell. 88 they list both with or without weight, 89 they list only one.

i trust my first hand experiances more than what ive read.

That would be someone putting the incorrect flex plate on it, since ALL, and I mean ALL GenII 660s are internally balanced. I bet that engine shook like a crack whore suffereing from withdrawl.

I too trust my first hand experiance and not what I read.

[geoffinbc]

Agreed once EFI (excluding TBI because it does not use a crank sensor) was introduced all engines were internal balance.

Did this flexplate have little weights welded on the back? If so this IS NOT an external balance flexplate these little weights are there to neutral balance the flexplate. Just like a flywheel is sometimes drilled out or drilld and filled with heavier metals to produce a neutral balance. This is like tire balancing.

[RacerX11]

Agreed once EFI (excluding TBI because it does not use a crank sensor) was introduced all engines were internal balance.

That is not true. '85 iron-head MPFI engines (non-TBI EFI) were NOT internally balanced. The Gen2 engines were internal from the beginning (1987+), while the gen1 MPFI engines switched in the 1988 model year (besides the Fiero, were there any other 1988 gen MPFI's?). Wasn't the '87 J-body still the gen1 enigne? If so, it should have been externally balanced.

Marty

[Guest]

Agreed once EFI (excluding TBI because it does not use a crank sensor) was introduced all engines were internal balance.

That is not true. '85 iron-head MPFI engines (non-TBI EFI) were NOT internally balanced. The Gen2 engines were internal from the beginning (1987+), while the gen1 MPFI engines switched in the 1988 model year (besides the Fiero, were there any other 1988 gen MPFI's?). Wasn't the '87 J-body still the gen1 enigne? If so, it should have been externally balanced.

Marty

'87 was the introduction of the genII 660 accross the board (except P-body), this includes the '87 (last year of the 1st gen J-body).
I think you were asking if there were any other '88 GenI MPFIs?
Yes, the F-body, which was MPFI up to the introduction of the 3.4 ('93 IIRC), which was then SFI.