Crazy idea...
Thread Starter
Junior Member
Joined: Sep 2017
Posts: 43
Likes: 1
Mercedes E550 4Matic
Crazy idea...
Morning guys. So I have been mulling over a retrofit for a few months now. Are the Intake-intercooler & turbo manifolds from the 4.7L M278 compatible with the 5.5L M273.
I know I know its cheaper to trade in. I have been hearing that for years and I have been hybridizing my cars for years also. From my 05 Subaru Legacy with and STI swap. To my 07 Infiniti M35 with a 08 drivetrain swap. Over and over I have been told it was not possible and over and over its been done and fairly straight forward.
I've sourced everything short of the actual long block. My only concern is are the manifolds compatible all the literature I have read says the blocks are the same. I just haven't confirmed their compatibility. The most cost effective thing to do is compare gaskets. I know there will be a degree of fabrication and some tuning will be needed. Has anyone had any experience working on these engines or knowledge of this or am I the 1st to consider something so crazy?
I know I know its cheaper to trade in. I have been hearing that for years and I have been hybridizing my cars for years also. From my 05 Subaru Legacy with and STI swap. To my 07 Infiniti M35 with a 08 drivetrain swap. Over and over I have been told it was not possible and over and over its been done and fairly straight forward.
I've sourced everything short of the actual long block. My only concern is are the manifolds compatible all the literature I have read says the blocks are the same. I just haven't confirmed their compatibility. The most cost effective thing to do is compare gaskets. I know there will be a degree of fabrication and some tuning will be needed. Has anyone had any experience working on these engines or knowledge of this or am I the 1st to consider something so crazy?
Super Member
Joined: Feb 2007
Posts: 616
Likes: 302
From: Republic of Texas
W203 W212 W211 R53MCS
The M278 and M273 engines are completely different engines. Starting with the fact that the M273 has 90 degree heads and the M278 has 45 degree heads. Don't think the exhaust and intake ports are the same either. But if you do the research let us know.
MBWorld Fanatic!
Joined: Dec 2011
Posts: 1,273
Likes: 129
From: Orlando, FL
2015 GL550 4matic
To do such projects on MB is far more technically daunting than Subaru or Nissan. Everything is tied together by computer programming. Good luck in your endeavors though. I think your best option would be to find a wrecked M278 car with all the parts you would need to swap into the M273 car, which is pretty much the same shell if you look at 2011 vs. 2012. I think the transmissions were also updated with the M278 engine change. You'll need someone who is a wizard with MB computer programming to pull it off regardless. To me, my time is the most valuable asset to consider. It will definitely be more cost effective just in parts to sell one and buy the other, then you also have the benefit of not having a car that is a Frankenstein and will retain resale value if you ever want to get rid of it. Projects to create something that was never sold in such a form can make sense to someone who is passionate, but doing all that work just to re-create something that can be easily purchased seems silly.
PS, I have seen builds of the W208 CLK converted to the E55 M113K supercharged engine (vs the CLK55 which did not have the Kompressor), and boy I would love one of those done.
PS, I have seen builds of the W208 CLK converted to the E55 M113K supercharged engine (vs the CLK55 which did not have the Kompressor), and boy I would love one of those done.
MBWorld Fanatic!
Joined: Feb 2014
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From: MA
2008 E350 4Matic, 2011 E350 4matic
I thought the main difference was that one was a 90 degree V6 and the other is a 60 degree V6 so completely different setup for the intake and other items.
You can just see the intakes on eBay, just search for those engines. They look completely different, even the shape is different which I guess would affect the gaskets too.
You can just see the intakes on eBay, just search for those engines. They look completely different, even the shape is different which I guess would affect the gaskets too.
Thread Starter
Junior Member
Joined: Sep 2017
Posts: 43
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Mercedes E550 4Matic
Well little update! I managed too pull it off... kinda sort of. My sister had a pretty major car accident totaling her car. It turns out my E550 was cheaper monthly and cost less than her base Mazda 3. Being the generous brother that I am I sold her my car and bought a 2013 E550. Not packaged as nice as the pervious car no air matic or parking sensors.... but I gained updated command, lane assist, blind spot assist and the reason for the crazy idea to start with the Bi Turbo engine.
MBWorld Fanatic!
Joined: Dec 2011
Posts: 1,273
Likes: 129
From: Orlando, FL
2015 GL550 4matic
Well little update! I managed too pull it off... kinda sort of. My sister had a pretty major car accident totaling her car. It turns out my E550 was cheaper monthly and cost less than her base Mazda 3. Being the generous brother that I am I sold her my car and bought a 2013 E550. Not packaged as nice as the pervious car no air matic or parking sensors.... but I gained updated command, lane assist, blind spot assist and the reason for the crazy idea to start with the Bi Turbo engine.
