ATX-MTX subframe swap question

[redshoman]

Having a '93 3.2 ATX (stock). I want to create an MTX but keep as much of the ATX components as possable. I have read, and been told that to accomplish this, you need to change the trans, subframe, motor mounts, and engine acc brakets and change the accesory drive to the two belt set up. I am curious why I cannot use the 3.2L complete motor, subrame, and keep the single belt serp system and use the ATX motor mounts. All that I have read seem "over complicated" I know that if it was easy enough people would just "toss" in the MTX-IV... so why not just swap the trans, linkage, pedal assem, and adjust the wiring and programing as such? I guess im conused why: if Im keeping the 3.2 in it, why cant i keep the block, heads, subframe and secondly the motor mounts and single belt system all complete. Is the fitment of the 3.2L block different than the 3.0L block with the ATX or MTX?

 

[rubydist]

The short answer is that the mtx engine sits several inches farther to the rear of the vehicle than the atx engine. To make the mtx axles line up, you will need to mount the engine in the mtx location - the simple way is to use the mtx subframe.

You can keep the atx serpentine belt, if you fab motor mounts accordingly.

 

[redshoman]

That would explain why I have read that people have to use the MTX exhaust manafolds and create a EGR block off plate. So I wonder what guys like Pheonex did when I created his own motor mounts. He used the MTX subframe and single belt serp system, but where did he locate the motor? in the ATX spot, or in the MTX spot. And what manafolds did he use (unless custom) and does the EGR work correctly? I'll have to write him...

 

[rubydist]

The motor needs to be in the mtx location to make the mtx axles work.

You can use the egr or not, as you wish. iirc, the manifolds are identical except for the egr/no egr (CA mtx cars also had egr), its the Y pipe that is different.

Conceptually, you need to position the engine in the right location, and modify the motor mounts to attach to the different location on the engine (since the motor mounts actually mount to the accessory brackets, which are different for the single belt v. the dual belt.)

 

[Phoenix]

I used the MTX subframe , the mounts of the ATX dont fit right. Plus it will be a real PITA to cut + weld the tranny support.

Then you need to fab up your mounts.

 

[redshoman]

I know that I will need to use the 3.0L y-pipe. I hope that it will clear the 3.2L oil pan, I know there is a "bolt" issue from the oil pan to the MTX-IV. The other bit that I saw was the timing and oil pump components were swapped, mixed matched.. why? I would like to leave it all 3.2L and just make motor mounts...

 

[Shoaz]

You can use the egr or not, as you wish. iirc, the manifolds are identical except for the egr/no egr (CA mtx cars also had egr), its the Y pipe that is different.

No, the ATX rear exhaust manifold dumps directly onto the steering rack in the MTX position, i.e., no way it's going to work. MTX exhaust manifolds required.

Hold two in your hand, you'll see the difference.

 

[Shoaz]

I know that I will need to use the 3.0L y-pipe. I hope that it will clear the 3.2L oil pan, I know there is a "bolt" issue from the oil pan to the MTX-IV. The other bit that I saw was the timing and oil pump components were swapped, mixed matched.. why? I would like to leave it all 3.2L and just make motor mounts...

None of that is really a problem. The bolt issue for the oil pan is just that one of the pan-to-tranny bolts doesn't align. It shouldn't hurt anything to just leave it out. Otherwise the main difference in the pans is that the oil level sensor swaps sides. In hindsight I'd have left the ATX oil pan in place, as it would have prevented rewiring that sensor and there's no real advantage to swapping them (other than the single bolt).

There's no problem leaving everything from the 3.2L in place and just dealing with the mount and subframe issues. I'm still running the ATX ECU as well.

 

[Phoenix]

I know that I will need to use the 3.0L y-pipe. I hope that it will clear the 3.2L oil pan, I know there is a "bolt" issue from the oil pan to the MTX-IV. The other bit that I saw was the timing and oil pump components were swapped, mixed matched.. why? I would like to leave it all 3.2L and just make motor mounts...

The pan doesnt matter , one has the oil level switch on the front , one its on the back , just a matter of making the wire longer if anything.