Difference between Euro and USA M117 4.5L engines.

Hi Volker,
I seem to recall that you have a 107 with Euro 4.5L engine.

There is a lady in New Zealand that has a Euro 74 350slc. Someone apparently swapped in an M117 4.L engine. However, they left the 350slc ECU and MPS in place. The car does not run very well! So she needs to find suitable ECU and MPS for the engine.

So question is - How would we determine whether or not she has a Euro or USA M117? The ECU/MPS part numbers are different. Engine number is 11798222022800.

Are the engines mechanically different - stroke, compression etc? I am away from home and don't have my reference info.

Any help appreciated.

Hi Graham,

actually M117 Standard and M117 US and M117 NV (Niederverdichtet = low compression) are 3 different engines. While we have a separate engine no. for NV, Standard and US version share the same engine nos.

That makes life difficult to differentiate. Neither cam shaft nos nor D-Jetronic or K-Jetronic injection components are a safe way to differntiate as they might have been swapped. What is different: Pistons and head plus ignition and injection components. So the only way to really know is compression. Or exhaust recirculation measurements which only US engines have.

I have written a German article on the 450 engine . Maybe that helps. You can see compression rate of 8.8:1, 8:1 and 7.5:1 . So if you have a leaking Standard version, you will also not be able to notice the difference. It is stupid that MB did not create 2 different engine nos.

EDIT: I forgot that I have also done it in EN: English article on 450 engine M117 .

PS: Since January, 2nd I have also taken over the biggest German forum on MB 107 SL /SLC, named Sternzeit-107.de (startime-107) . Currently I modernize it and it will also have an English speaking forum for the 107.

Thanks Volker,
I wondered if the the '22' in the engine number might help in determining which engine she has. The first '2' indicates engine was intended for a Right Hand Drive car. This would rule out European and US cars. What we don't know, is if engines with the 8.8:1 compression ratio M117 were built for Japan, South Africa, UK and other RHD countries.. This car was imported with a M116 engine, but the source of the engine is unknown.

Do you think the German Classic center might have a data base that would allow us to determine which M117 engine this is? I suppose we should just ask.

Finally, the lady is running out of money! A few options come up:
- leave M116 ECU/MPS in place and try and adjust mixture using MPS so that car does not run rich as it does now (It has the blue 036 injectors)
- install lower capacity yellow injectors (if they can be found used) or equivalent and again adjust MPS.
- install USA MPS and ECU and see how it runs (lean?) adjust if need be.

It is an unusual situation.

Interested in your new 107 site - My German is very limited, so look forward to the English version. Mind you, Chrome does automatic translations, so I will have a look.

PS: I will send her the link to your M117/4.5 page.

Hi Graham,

well a left hand could very well be European! O do you consider England, Wales, Scotland and Northern Ireland non-Eurpean? Well, one might wonder these days...

However a righr-hand engine M117.982 or M117.985 engine should always be a Standard engine. US versions were only delivered to US and CAN and they were always left-hand cars. But for sure she needs to swap ECU, ignition distributor, injectors and MAP sensor. Tell her to log in here, we might find a deal. But first she should be sure which exact components are installed.

When I lived in UK, Europe was on other side of the channel

I sent an email to MBUSA Classic center to see if they have an engine database.

Owner is in New Zealand, so assuming RHD, motor could have come from Japan, South Africa or other Asian countries or even UK. You are saying that all of those would have the 'standard' 8.8:1 compression M117?

Problem she will have, is that unless someone would swap her M116 ECU/MPS for a Euro M117 ECU/MPS, she would looking at quite a lot of money for the parts, even with a good deal

Hi Graham,

yes I mean that all RHD engines should be Standard engines.

If she finds someone to swap those parts (don't forget injector and ignition distributor?) in NZ that would be great. Otherwise shipping is already expensive.