C43 to C63 engine swap
Thread Starter
Junior Member
Joined: Sep 2021
Posts: 72
Likes: 5
2017 C43 Coupe
C43 to C63 engine swap
Hi guys, so as of right now my engine is ceased. I have to replace my engine. I noticed that used c43 engines aren’t that much cheaper than C63 engines. And I heard rumors the w205 transmission on c63 is same as 43. I want to swap for c63 engine but here are some problems I was hoping y’all could give some opinions on:
1.) engine bay size difference: the c43 engine bay might not have room to accommodate 4Liter engine
2.) AWD: the c63 engine and ecu is built for RWD
1.) engine bay size difference: the c43 engine bay might not have room to accommodate 4Liter engine
2.) AWD: the c63 engine and ecu is built for RWD
Junior Member
Joined: Nov 2017
Posts: 31
Likes: 4
From: California
2006 E55 Stage 3 Eurocharged 2005 E55 VRP Tuned 2015 CLS63 AMG-S
You will for sure need ECU, maybe even wiring. I know the differential is different c43 is regulated via torque vectoring but the c63 comes with and LSD. You will also need to change the brakes to handle that power, as far as transmission it's a little iffy there.
Out Of Control!!
Joined: Nov 2018
Posts: 11,398
Likes: 5,322
From: San Francisco Bay Area
2019 C63CS
That would be a major and costly project, and you'd be better off buying a C63 most likely. As you already discovered, the V8 doesn't fit the regular C chassis. The C63 is longer in the front to accommodate the V8. Second point, the transmission in the C63 is not the same as the 43. The C63 has what AMG calls a multi clutch transmission. Instead of a torque converter it has a wet clutch. This setup is optimized for the V8. While there is an AWD variant available of the 9 speed MCT used in cars like the E63 with a transfer case, this is for the fully variable 4Matic+ and not the old 4Matic in the 43. In addition as already mentioned, the C63 prior to 2019 had a mechanical LSD and the C63S and 2019+ C63 have an electronic locking differential. Same is the case for the E63 in combination with 4Matic+. This will also affect DYNAMIC SELECT as the different drive modes affect the operation of the differential. The ESP would also have to be adapted to work correctly with the new powertrain. The 2019+ C63S even has a completely different traction control. It's the 9-stage traction control from the GT R. You'd essentially be replacing everything to make this work unless you are skilled enough to do a custom build and tune/adapt your existing 43 drivetrain to the V8 and make sure it all holds up. For reference, there is a W204 C63 BS that was turned into AWD, so I suppose it's all possible with enough time and money.
Last edited by superswiss; Nov 17, 2022 at 01:49 PM.
Super Member
Joined: Oct 2019
Posts: 841
Likes: 315
C43
Sorry to hear that your engine ceased. Do you know the cause? Tune related lean conditions, main/rod bearing, oil starvation, rods, etc? I agree with above, not worth the money and you are better off selling your car as is, or putting a new short or long block into the car (depending on how extensive the damage is).
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Joined: Nov 2022
Posts: 8
Likes: 1
From: Alpharetta, GA
C63S AMG
From working in the automotive performance industry for a couple years now I would heed the advice of some others and look for a replacement engine. If you truly want a C63 it will likely end up cheaper overall to just purchase one. You're going to run into big ECU and wiring harness issues and that's just the very beginning. While the transmissions are similar across this platform it's just going to be as plug-in-play as you might think. The cooling side of things is going to be another nightmare given the architecture of the front end is completely different.
Not saying it's impossible, but not feasible on a normal budget.
Not saying it's impossible, but not feasible on a normal budget.
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