Chrysler V8 Conversion thoughts?

DomCLK

Senior Member
Joined
Apr 8, 2014
Messages
137
Reaction score
0
Age
32
Location
Bedford
Your Mercedes
CLK270 CDI
Hi folks,

Now I know this sort of thing has been discussed before since time immemorial but it's in my head again. I sold my CLK about 18 months ago and I've been missing it ever since, now I'm thinking of a daily driving future project.

Engine swaps are notoriously complicated I know, especially with newer Mercs but what does everyone think about something like a Chrysler Hemi? From what I understand the Chrysler 300C shares a lot of architecture with the E Class and is fitted with the 5G box so I'm thinking of a cheap CLK500 as a starting point and going from there.

Thoughts?
 

LostKiwi

Senior Member
Joined
Aug 25, 2006
Messages
26,501
Reaction score
15,957
Location
Midlands / Charente-Maritime
Your Mercedes
'93 500SL-32, '01 W210 Estate E240, 02 R230 SL500 (Malcolm Spec), 04 Smart Roadster Coupe
You'd probably be better starting with a CLK55 and extracting more power from that if thats what you want (or swap in the 55 engine and transmission).
Not all 5G gearboxes are the same either. If you wanted to extract big power you would probably need to upgrade the box to a higher torque variant. The 5G box will cope with variously 300Nm to 1000Nm depending on variant.
 
OP
D

DomCLK

Senior Member
Joined
Apr 8, 2014
Messages
137
Reaction score
0
Age
32
Location
Bedford
Your Mercedes
CLK270 CDI
  • Thread Starter
  • Thread starter
  • #4
The CLK500 already has a V8, why would you swap it?

To make it more exciting.

My thought trail went like this....

'Hmmm I'd like another Merc but something AMG fast but not AMG money"

Nitrous! Play and spray, cheap and cheerful until it's not enough and I melt a piston or butt a ring and crack a piston. Nah.

V8 Swap! LS3 V8 5.3-6.2 plenty of power, plenty of torque and the best aftermarket support. They do Jeep conversions so make an adaptor for the 722.6. Hmmm too radical.

Which led me to Chrysler, they put the Hemi V8s in the 300C along with the 722.6, just seems logical.
 

Craiglxviii

Senior Member
Joined
Sep 6, 2015
Messages
15,870
Reaction score
4,917
Location
Cambs UK
Your Mercedes
W215 CL500 Motorway Queen; W251 R320L Familybenz, S211 E320 Avg Designo Edition now sadly missed.
Sounds chuffin’ Radio rental to me.
 

Craiglxviii

Senior Member
Joined
Sep 6, 2015
Messages
15,870
Reaction score
4,917
Location
Cambs UK
Your Mercedes
W215 CL500 Motorway Queen; W251 R320L Familybenz, S211 E320 Avg Designo Edition now sadly missed.
There’s a reason that MBS don’t lend themselves to the mod scene...
 

LostKiwi

Senior Member
Joined
Aug 25, 2006
Messages
26,501
Reaction score
15,957
Location
Midlands / Charente-Maritime
Your Mercedes
'93 500SL-32, '01 W210 Estate E240, 02 R230 SL500 (Malcolm Spec), 04 Smart Roadster Coupe
They put Jaguar V8s in front of 722.6s as well but I still wouldn't do it....
 
OP
D

DomCLK

Senior Member
Joined
Apr 8, 2014
Messages
137
Reaction score
0
Age
32
Location
Bedford
Your Mercedes
CLK270 CDI
  • Thread Starter
  • Thread starter
  • #8
They put Jaguar V8s in front of 722.6s as well but I still wouldn't do it....

Neither would anyone unless they've got their head on backwards, you're just swapping one engine with little support for another with little support.

I'm trying to work out if it's a case of modding the 500 and spending a fortune on Kleeman et al kit or swapping it for something better supported by the aftermarket and also spending a fortune.
 

turbopete

Senior Member
Joined
Feb 4, 2009
Messages
14,204
Reaction score
328
Age
45
Location
Spennymoor
Your Mercedes
2010 '60' Ford Mondeo 2.0TDCi Zetec (sorry)
as you are UK based, id avoid a hemi swap. yes theres plenty of info and support around but its mostly American stuff. and after all, chances are most V8s are 'hemis' nowadays (hell, if you want to get technical, a 1983 Escort 1.3 CVH engine is a 'hemi') If you buy something with a V8 already in it and the engine is sound my thoughts would be supercharger or turbo conversion, lightweight torque converter (surely someone must do them) to allow the engine to rev up quicker, decent LSD if the 500 doesn't have one already and NOS if you feel the need. I'm guessing here but id guess that a turbo'd 500 would give the 55k AMG fitted to the same car a run for its money, without needing to run silly boost figures
 
OP
D

DomCLK

Senior Member
Joined
Apr 8, 2014
Messages
137
Reaction score
0
Age
32
Location
Bedford
Your Mercedes
CLK270 CDI
  • Thread Starter
  • Thread starter
  • #10
Unless you get the Lean-burn CVH head which is just gopping. True Hemi heads are mostly phased out for more efficient designs but they're simple and effective.

The main reason for suggesting a Hemi V8 is from the Chrysler/Mercedes connection.

What is the biggest hurdle with engine swaps in modern Mercs? Is it the electronics?
 

LostKiwi

Senior Member
Joined
Aug 25, 2006
Messages
26,501
Reaction score
15,957
Location
Midlands / Charente-Maritime
Your Mercedes
'93 500SL-32, '01 W210 Estate E240, 02 R230 SL500 (Malcolm Spec), 04 Smart Roadster Coupe
The electronics between engine, gearbox, traction control, ESP, security, instruments are tightly linked.
There are also considerations of Euro classification to take into account (for LEZ etc).
 

V6Matty

Senior Member
Joined
Aug 1, 2012
Messages
7,458
Reaction score
2,094
Location
Newark, Notts
Your Mercedes
S212/10/E350(His) W169/2005/A180 (Hers)
As above, essentially your have to do bespoke coding of all the systems on a mopar ecu and hope to hell it all works
 
OP
D

DomCLK

Senior Member
Joined
Apr 8, 2014
Messages
137
Reaction score
0
Age
32
Location
Bedford
Your Mercedes
CLK270 CDI
  • Thread Starter
  • Thread starter
  • #13
Have we a resident Merc Electrics Guru? I don't have a huge amount of practical electronics experience on new cars, just theory, old cars are easy as you get a stand alone ECU that once wired to the engine you just need to hook it up and away you go.

I'm assuming this approach is nigh impossible as the ECU in a Merc handles so many functions from ABS and TC to anti theft etc.

So what I've thought is ECUs are just computers that give a given output for a given input and so can be manipulated. Is it possible to isolate the engine controls from the main ECU? The lines I'm thinking along involve running 2 ECUs in series, the engine controls being run from it's dedicated ECU with inputs from the throttle, TCM etc and the main ECU?

Some of the ideas I have are quite difficult to express and write down as they're not really easily translated from the internal voice in my brain to the common english language.
 

LostKiwi

Senior Member
Joined
Aug 25, 2006
Messages
26,501
Reaction score
15,957
Location
Midlands / Charente-Maritime
Your Mercedes
'93 500SL-32, '01 W210 Estate E240, 02 R230 SL500 (Malcolm Spec), 04 Smart Roadster Coupe
ECUs are just computers however they talk to each other over a CAN bus (or in MBs case several CAN busses).
The CAN bus is a network linking multiple sections of the car together (this is how almost all modern cars since 2001 work).
The communication over the network takes place using a protocol (effectively a combination of data and commands presented in a given format understood by all the modules). The protocol used is often proprietary, partly for security reasons (if it wasn't proprietary anyone could plug a box on the CAN bus and drive off with the car) and partly to restrict aftermarket modifications that could compromise the vehicle.
To do anything with the CAN bus would require reverse engineering the protocols format used and the command sets.
The only other way around this is to junk CAN altogether and hard wire the rest of the car the old fashioned way. That won't help if you plan to use an MB gearbox...
The CAN bus goes to (dependent on vehicle) engine, gearbox, security system, radio, instruments, doors (for electric window control), ABS, ESP, lighting systems and so on. Even tail lights are often CAN controlled via the rear SAM.

You can run an ECU in parallel to the original ECU (that's how modern LPG installations work) but the information flowing from one to the other will need to be spot on to prevent limp modes.

You may get away with adapting an LPG ECU to act as the interface from one to the other.

Frankly I'd put the whole idea into the 'its not worth it' basket.
 
Last edited:

turbopete

Senior Member
Joined
Feb 4, 2009
Messages
14,204
Reaction score
328
Age
45
Location
Spennymoor
Your Mercedes
2010 '60' Ford Mondeo 2.0TDCi Zetec (sorry)
Unless you get the Lean-burn CVH head which is just gopping. True Hemi heads are mostly phased out for more efficient designs but they're simple and effective.

true but they tended to be fitted to the 1.4 in the Escort/Orion and the 1.8 Sierra. the 1.3 and 1.6 CVH were usually not lean burn.

as for the MB/Chrysler connection, as far as I'm aware, the mechanicals may be similar but I believe the electronics are a world apart.
 

Comand Online Ltd is a specialist supplier of Mercedes Navigation Disks, Phone & Bluetooth, iPod, DAB, CD and other COMAND retrofit parts to enhance your vehicle.www.comandonline.co.uk
Top Bottom