A question about the dreaded 420a to 4g63 swap...

[Wilfus65gs]

I know that everyone is always saying that the 420a to 4g63 swap is almost impossible and is very expensive. But i was wondering what it is that is so hard to do about it... Would you not just have to get the motor, tranny, all the front axles and such, and a turbo ecu??? What is the big problem with attempting this swap b/c i need a new motor and the turbo motors about half the price of a 420a non-turbo (it would be great if someone could explain that one to me also...) thx...

 

[miamieclipse]

If i'm not mistaken it's not that the turbo mounts wont work on the 4g63 engine but that there is no where to mount them on the 420a engine bay....

 

[GSGoinFast]

it takes custom fabbing of mounts, plus a lot of wiring of the new harnes to go into the ecu. and theres other stuff but i cant remember. search on here or 2gnt.com

EDIT: oh yeah, you say the turbo motor is half the price of the non turbo motor, but, after the price of the transmission, the ecu, and the axles and other junk you need, you far surpass the price of a new NT motor.

 

[daver36]

Okay, Here's my questions about this swap. Does it really take custom mounts? I know the engine/tranny is 180 degrees the wrong way but couldn't you get the proper mounts off a donor car from the wreckers and put them in? A couple years back I helped a buddy put a Type R B18 in his EG civic. The car was originally an automatic which puts the main tranny mount on the passenger side to high (or low, I'm not sure anymore). All we did was drill out the spot welds for the auto mount (i'm obviously talking about the section of the mount that's welded to the car, not the actual mount that bolts to the tranny and then the part that i'm talking about) and remove it, went to the wreckers and pulled a mount of a manual car and welded it in where it would be on a manual car. It really wasn't that hard at all (i know a little about motors and stuff, but this was my first ever swap). Couldn't you do the same in the dsm or am i missing something? If you can, after that everything is easy, swap the wiring harness and ecu. I know everyone says it's not worth the time but the fact of the matter is clean 4G63 dsms are getting harder and harder to find (at least in my area), so if you've got some know how and can find a really clean 420a dsm, why not?

 

[bedlam]

Best thing to do is to take a look at the 4g63 engine bay and the 420a engine or better yet take a picture of your 420a engine compartment then flip the picture 180 degrees and there is your difference. The mounting locations in the actual engine compartment are completely different which is why custom mounts are needed to be made. The motor mount on the passenger side in front of the strut tower on the 420a is on the driver side in front of the strut tower of the 4g63. Yeah you could cut out the engine mounting areas from a 4g63 donor if you really wanted to but I would not want to be in that car when those mounts break. I do not care how good you think your welding is, it will break under the right conditions.

The things about hondas and acuras is that it is easy to do swap and such because they are a dime a dozen and the engine bays are not reversed like mitsubishis.

The reason why everyone says to just sell the 420a car and buy a 4g63 car is that by the time you spend the money on buying all the stuff you need, then having custom mounts made, the money adds up to what you would spend on buying a 4g63 car, give or take depending if its been molested or not.

Needless to say is it cost effective to swap the 4g63 motor, tranny, axles, turbo, wiring harness, computer, smic and whatever else you think you need.....No. Is it more cost effective to sell the 420a and put that money along with the money you would spend on the 4g63 parts and buy a eclipse/talon that is already 4g63 from the factory....Yes. Can the swap be done.....Yes but it is a long and painful process and you might get CEL codes a majority of the time you have the car.

 

[daver36]

Soundz good. The explanation was what I was looking for most. I hate the just "don't do it, that's all you have to know" response. Thanks alot.

 

[psycho]

You have to fabricate the passenger and drivers side engine mounting points in the bay. In the 420a bay, you would have to remove the ECU and fuse boxe and weld in a piece of metal, just like on the passenger side, to create a mounting point for the drivers side mount.

The transmission mount, you would have weld pieces of metal the frame rail.

If I could find a wrecked 4g63 car for cheap, i'm meaning ~$1k, I would do it. I have a plasma cutter, MIG and TIG welders at my finger tips, knowledge and lots of time.

 

[turbodoug]

Look closely at the frame rails and shock towers in the engine bays on both cars. You will notice that they are absolutely inverted... meaning that mounts, bolts holes for accessories, etc. are all on the opposite side of the engine bay. The most notable issue is that the hump in the frame rail (for the transmission to clear) is on the opposite side. Also, the driver's side frame rail bows out on a 4G63 chassis, but inward towards the engine bay on the 420A chassis. I'm not yet sure if the front of the 4G63 will clear, but I'm about to find out. One, if not both, frame rails will need to be notched pretty good to pull it off.

But yeah, these guys are pretty much correct. Unless you're planning on chopping the car pretty good, and also re-wire everything, then it's not very efficient to try using the 420A-powered chassis as a starting point.