Engine swap: W123 300TDT => W115 - PeachParts Mercedes-Benz Forum

HansAA · #1 03-03-2009, 08:28 AM

After quite a while with considerations I've finally decided to try make this happen. It is a well known issue, and it has been done a number of times with various results. I am gonna use my 4 speed manual tranny first. Later I will try to fit a W124 5 speed manual. With an adapter.

At the moment I am trying to decide on which one of these two engines I should buy:

1: -85, about 170 000 miles, "ambulance version" with about 145hp = 108 kW. "Engine does not run properly while someone dismantled the pump and put it back without adjustments."

2: -83, unknown driven distance, from a parts car no more among us. Was then in good running condition with minimal oil consumption. Passed the blow-by test with the cap staying calmly at the top.

With both I get the airfilterbox, servo pump etc... And they are equally priced.

Which engine is the better? Does it over time harm such an engine to be run with this ambulance trimmed(?) setup?

I don't got that much time to decide on this. Please help me out. I have never owned one of those machines myself.

#2 03-03-2009, 08:42 AM

No such thing as a 145hp "ambulance version". The 617a was 110hp pre1980 and 125hp 1980-1985.

The 83 sounds like a far more reliable choice.

HansAA · #3 03-03-2009, 08:58 AM

Hmm. I'm not sure myself. But I know that the ambulances over here normally were trimmed whether they burned gas or diesel.

#4 03-03-2009, 09:18 AM

The part about "Engine does not run properly while someone dismantled the pump and put it back without adjustments" gives a big clue. The owner was playing around with the pump trying to get more power out of it and is guessing it has "145hp".

That is close to how much power the engine can make with the stock injection pump maxed out.

kerry · #5 03-03-2009, 09:20 AM

Maybe the ambulance has a truck 617 in it or something like that.

tompaah7503 · #6 03-03-2009, 09:30 AM

At least all W115/W123 ambulances delivered to Sweden had gasoline engines, I think they were M110/280's (= 145hp). Would suspect your 85 is in fact a gasoline engined car, or someone swapped in a OM617 but didn't change the registration data properly.

diametricalbenz · #7 03-03-2009, 09:47 AM

Are you planning to move the oil filter?

Have you resolved the turbo clearance issue fit of the OM617.95x motor in a W115?

HansAA · #8 03-03-2009, 10:42 AM

Quote:

At least all W115/W123 ambulances delivered to Sweden had gasoline engines, I think they were M110/280's (= 145hp). Would suspect your 85 is in fact a gasoline engined car, or someone swapped in a OM617 but didn't change the registration data properly.

Yeah? I don't see why it should be different over here then. But the thing is that this is a loose engine.
The guy is trying to get rid of two parts cars and one engine. One W123 300D ambulance without turbo(!), one regular W123 300TDT, PLUSS an "ambulance" 300TDT engine.

Quote:

Are you planning to move the oil filter?

Of course, you HAVE to do that. Adapter plate. He, he.

Quote:

Have you resolved the turbo clearance issue fit of the OM617.95x motor in a W115?

I think I know about most of the issues concerning this swap. I will get a W115 300D parts car for all the rest I need...

Yes, I will meet problems. Yes, they never came out with manual transmission. Yes, this engine-manual trans. setup will not be completely balanced. I know.

But which engine should I go for?

diametricalbenz · #9 03-03-2009, 11:09 AM

Sounds like the 83 is in better shape.

The reason I asked is because I am doing a same swap, OM617 with a 4 speed into a W115.

HansAA · #10 03-03-2009, 11:40 AM

Ahhh... Cool! How fare have you come? I hope I get this through during the summer. Winter is still here and I only got a carport... At the moment I am trying to collect all the most needed parts before my exams in may/jun are due...

There were differences between US and european diesel models for sure. I guess I'm just trying to figure out if there were W123 "ambulance" models delivered from the factory at all. Probably you yanks can't help me. I assume you had other typical ambulance cars. GM?

My brothers W115 ambulance car they had for the norwegian two week long "high school graduation celebration", was a trimmed straight-6. Who did the bodywork and trimming I don't know. But it was trimmed for sure.

diametricalbenz · #11 03-03-2009, 11:47 AM

So far the engine is done but as my signature says it's an OM617.910 from a N/A 300D /8 donor car. We're just swapping the front ends of the cars to the 240D and cutting the driveshaft and rods to make everything easier. I reluctantly went with the 910 motor since I wanted turbocharging and to max out the MW pump but we're planning to put
light boost on the motor anyhow.

Were you planning relocate the oil filter or graft on a new one with flexible hoses?

Yes we have Ford Econoline F250 ambulances. Powerstroke 7.3L V-8 diesels. Perhaps 6L now?

HansAA · #12 03-03-2009, 12:37 PM

Quote:

Were you planning relocate the oil filter or graft on a new one with flexible hoses?

I'm gonna go for the easiest solution first. Adapter plate and move it to wherever close it fits. It seems like the original filter setup worked out nicely over the years, or what? No need to change that as long as you got cheap filter suppliers.

Ford? We also had a lot of them until recently. VW has taken over...

bgk202 · #13 03-13-2009, 05:24 AM

I'm wondering what accessories you can leave on (and which need to be swapped) when you install a w123 300d motor in a w115? I realize that I'll need to swap intake manifolds and install a remote oil filter. But does the A/C compressor, alternator bracket, thermostat housing, vacuum pump, steering pump, injection pump, motor mount brackets, etc., all have to be swapped, or is there enough clearance where it's possible to drop the engine in with all those w123 components and make it work in the w115 300d body?

HansAA · #14 03-13-2009, 08:24 AM

I am not sure myself, but as far as i know you can leave everything but the oil filter on the engine. The ac i don't know much about, but on this picture from a german installation the ac pump has got a little strange location, dont you think? A/C i wont care that much about in the beginning. He, he. I come from Norway.

diametricalbenz · #15 03-13-2009, 09:57 AM

The only other difference I can think of is the plumbing for the A/C since the compressor moves from the exhaust manifold side to the below the PSP since you're going from a York to a R4.