Fitment Question - PeachParts Mercedes-Benz Forum

tram · #1 08-01-2007, 01:25 AM

Hi All-
I'm trying to save an old 108 chassis 250SE for a friend of mine. It has an engine that was run low on oil and now knocks and smokes badly. I've located several W114 chassis cars with carb'd 6 cylinder engines in my area that are cheap with good running engines. Aside from the obvious changes that would be necessary to run carbs on the 250SE, will an engine from a 1972 250C bolt up if I change the mounting arms from the 108 car? What obstacles am I looking at? I can handle most anything but want to be sure that there isn't anything insurmountable before I buy a W114 and begin the transplant procedure. Thanks in advance.

Mark DiSilvestro · #2 08-01-2007, 09:06 AM

The 72 250C engine should be an M130 2.8 with twin Zeniths. The one in my car is actually marked '280S' on the cylinder head. Should bolt right in to your SE. You'll need to convert from the stock electric fuel pump.

Happy Motoring, Mark

tram · #3 08-01-2007, 12:50 PM

Mark, thanks for the info. That's kind of what I thought.

MunichTaxi · #4 08-01-2007, 10:29 PM

The W108 uses different headers and the rest of the exhaust sytem, compared to a W114. The exhaust runs over the rear axle differently, also.

Be sure to get the front half of the W114 exhaust system with the motor.

tram · #5 08-02-2007, 01:08 AM

Quote:

Originally Posted by MunichTaxi

The W108 uses different headers and the rest of the exhaust sytem, compared to a W114. The exhaust runs over the rear axle differently, also.

Be sure to get the front half of the W114 exhaust system with the motor.

Would it be better to swap the exhaust manifold?

t walgamuth · #6 08-02-2007, 06:19 AM

Did you try changing the oil and using fresh thick oil?

Mr. Obvious here.

Tom W

Mark DiSilvestro · #7 08-02-2007, 07:08 AM

Quote:

Originally Posted by tram

Would it be better to swap the exhaust manifold?

Intake and exhaust manifolds bolt together on the carbed engines, so the FI SE exhaust manifold won't work. If that 250C exhaust manifold doesn't fit the SE exhaust, your best bet is the manifolds off a carbed W108 280S.

Happy Motoring, Mark

tram · #8 08-02-2007, 11:17 AM

Quote:

Originally Posted by Mark DiSilvestro

Intake and exhaust manifolds bolt together on the carbed engines, so the FI SE exhaust manifold won't work. If that 250C exhaust manifold doesn't fit the SE exhaust, your best bet is the manifolds off a carbed W108 280S.

Happy Motoring, Mark

Mark, on this 250SE the manifolds both bolt together on the passenger side. This is a '67 with mechanical injection. I've actually seen a couple of these engines where the owner wasn't knowledgeable enough to repair/ diagnose the FI, and they just bolted an intake manifold and carbs right on in place of the FI air intake manifold. Is there something else I'm missing?

wbain5280 · #9 08-02-2007, 01:29 PM

Quote:

Originally Posted by tram

Mark, on this 250SE the manifolds both bolt together on the passenger side. This is a '67 with mechanical injection. I've actually seen a couple of these engines where the owner wasn't knowledgeable enough to repair/ diagnose the FI, and they just bolted an intake manifold and carbs right on in place of the FI air intake manifold. Is there something else I'm missing?

Doing that will cause the FI pump to get 'damaged' and seize. Alos, you cannot just pull the injection pump off since it's bolted to the block. The M180 carbed engines have a different block casting, hence the difference between the 250SE M129, 280SE M130 and the W114/5 M180.

You can pull the engine and replace it with a carbed version and you will need the exhaust header. Instead, find a 280SE engine and swap it for the 250SE engine. Slightly more power too.

tram · #10 08-02-2007, 05:02 PM

Yes, I've been looking for a good 280SE engine as a substitute for several weeks, with no luck. That would be the ideal situation. Aurora in Seattle no longer deals in anything older than 1990, and Benz Friends has liquidated their engine inventory. I did find two, but both back East and way more $$$ plus shipping $$$ than I want to spend for an engine in unknown condition. I actually found two 250Cs in my area dirt cheap, and I can at least drive the cars and see what I'm getting. I personally prefer injection over carbs any day - BUT - I'm doing this as a favour for an old customer of mine, an older German lady who is alone and doesn't have thousands of clams to shell out. She just wants her baby to run.

Mark DiSilvestro · #11 08-03-2007, 08:49 AM

Quote:

Originally Posted by tram

Mark, on this 250SE the manifolds both bolt together on the passenger side. This is a '67 with mechanical injection. I've actually seen a couple of these engines where the owner wasn't knowledgeable enough to repair/ diagnose the FI, and they just bolted an intake manifold and carbs right on in place of the FI air intake manifold. Is there something else I'm missing?

But you're talking about installing a complete carbed 250C engine into your 250SE, with the possibility that the 250C exhaust manifolds won't bolt up to your 250SE header pipes. I don't think the 250SE exhaust manifolds will work on the carbed 250C engine. The 250C carb manifolds are not only bolted together at the head, but also bolt to and support each other, at a rectangular manifold heat-control box under each carb. If the 250C exhaust manifolds won't bolt up to your 250SE exhaust, then your choices include installing a set of manifolds off a carbed W108 250S or 280S, or have your SE exhaust system custom-made/modified to fit the 250C engine. Maybe the 250C header pipes can be welded to the rest of your SE exhaust.

Happy Motoring, Mark

tram · #12 08-03-2007, 12:39 PM

Quote:

Originally Posted by Mark DiSilvestro

But you're talking about installing a complete carbed 250C engine into your 250SE, with the possibility that the 250C exhaust manifolds won't bolt up to your 250SE header pipes. I don't think the 250SE exhaust manifolds will work on the carbed 250C engine. The 250C carb manifolds are not only bolted together at the head, but also bolt to and support each other, at a rectangular manifold heat-control box under each carb. If the 250C exhaust manifolds won't bolt up to your 250SE exhaust, then your choices include installing a set of manifolds off a carbed W108 250S or 280S, or have your SE exhaust system custom-made/modified to fit the 250C engine. Maybe the 250C header pipes can be welded to the rest of your SE exhaust.

Happy Motoring, Mark

Mark- Yep, I forgot about the carbed manifolds bolting together as a heat riser. I'll have to modify the headers.. shouldn't be a big deal to Frankenbuild and braze. Thanks again.

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