Engine swaps - PeachParts Mercedes-Benz Forum

FineOlBenz · #1 10-31-2004, 07:36 PM

I just finished a 240D everything was pretty basic except the donor motor was not an EGR model and that was easy enough. The next swap will not be so easy. I have set up to get a 1980 300D non turbo car and I'll be transplanting a 1983 300 Turbo motor and trans into it. From what I can see the tranny mount is further back than the 240 that I just worked on but the body is the same. Is the transmission different on the 300D non turbo to the 1983 turbo models. If so the drive shafts are likely different also. The radiators and heater hoses are slightly different as I recall. Is there anything else? Should I entertain the idea of changing the turbo motor to a non turbo by swaping manafolds and oil pans? Are the basic motors that much different internally?

Thanks for some advice before I dive.

There was one small change thought. In my search for vehicles I did find a 1982 380SL with a bad motor. I'd like a diesel convertable. Can't you smell the fresh Feedom Frys?

psfred · #2 10-31-2004, 09:24 PM

Everything will fit right in, but you do need the radiator and oil cooler (if different) from the turbo. Get the tranny too, if you can, and the tranny control stuff. Driveline should be identical except the diff.

You would be ahead to change the diff, as well. The turbo has a different gear ratio, and you will appreciate it -- drops engine rpm quite a bit, and will raise the top speed from about 95 to about 115.

Peter

FineOlBenz · #3 10-31-2004, 10:16 PM

What tranny controls? Is the auto transmission the same in both models? The rear differential does not look promising from the wrecked turbo car. Even more promising 115 better be out of the question for someone who cannot handle 35 mph in the rain. Are the injector pumps the same in case I need to make the turbo motor a non turbo? The non turbo body has no water pump on the heater. I guess I'll just have to figure that one out too.

kamil · #4 10-31-2004, 10:40 PM

Hey.

When you took out the 240D engine did you take out the radiator first ?
Can you list the major things you did in order while you were taking the engine out ? I will be doing mine shortly as well.

Thanks

Kamil

Lycoming-8 · #5 10-31-2004, 11:40 PM

Why do you think that you might need to make it a non-turbo? Think that you will much prefer it to be turbo'd. If the engine going in the car was originally turbo'd, it will have the better crank, oil jets for the bottom of the pistons and a few other refinements that would be a shame not to take advantage of. Even if you need to acquire a replacement turbo they are not too difficult to find.

#6 11-01-2004, 01:18 AM

The drive shafts are different but I think it is only the intermediate shaft that is, the short drive shaft. The long drive shaft might be the same I don’t recall. The transmission is different and some times the transmission cooler lines have differnt size connectors there is a small size and a large size where the metal cooler line connects to the transmission. If you do this you really need to have the donor car right there till you are completly done wait 2 more weeks then you can start to think about getting rid of the donar car/
Dave S

FineOlBenz · #7 11-01-2004, 09:17 AM

Unfortunately I have the donor car, See pic above. As we found out doughter-inlaw is not an experienced driver. But she's ok thats the main thing. I'd rather have a good 240 body to work with due to climate controls and windows though.

psfred · #8 11-01-2004, 08:50 PM

You can leave the heater stock.

The vaccum amplifier for the transmission includes an input for the boost signal, too, so I'd use that one to prevent trouble.

Peter

MTUpower · #9 11-01-2004, 09:14 PM

what about the oil pan swap and other parts to make a turbo out of non turbo block? I got the parts here in florida....

mikemover · #10 11-01-2004, 09:32 PM

I'd pull the engine and tranny together and change both...It's easier to pull them out together anyway.

I think mattdave is right about the driveshaft being different as well.

The car will "work" without changing the differential, but the gearing is different, which means you'll be running the engine at a higher than normal RPM range at a given speed. This will be especially noticeable at highway speeds, so you'll probably be happier with the results if you change the rear end as well.

I also think the compression ratio is lower on the turbo engines, so if you converted your turbo engine to a non-turbo, you'd most likely have a 35 horsepower boat anchor. Can someone else confirm this about the compression?....I'm pretty sure I am correct.

Mike

MTUpower · #11 11-01-2004, 09:50 PM

commpression on the N/A is higher by about a pound. Would give you more power but a shorter engine life I think... fine with me if the rest of the swap could take place

mikemover · #12 11-01-2004, 10:54 PM

Quote:

Originally Posted by MTUpower

commpression on the N/A is higher by about a pound. Would give you more power but a shorter engine life I think... fine with me if the rest of the swap could take place

I think we're talking from different directions here....

I'm talking about Fine'olBenz's idea of removing the turbo from his engine to make it a non-turbo...which I think would result in a real dog of an engine, because with the lower compression it would not make much power without its turbo.

If I understand you correctly, I think you're talking about making a non-turbo engine a turbo, which from what I have heard and read is also inadvisable because the non-turbo engines are not built for it...they will not hold up under the additional stress. The compression is too high for the boost that the turbo provides. The low end--main bearings and caps and such--are not as beefy, and I think they lack the oil jets that cool the pistons as well...the injeciton pumps are calibrated differently...I'm sure there are other differences as well.

Just from lifting the hood, the turbo and non-turbo versions look very much the same, but there are critical internal differences.

Mike

#13 11-01-2004, 11:46 PM

While some company manufacture a turbo for 240d and 300d non turbo engines the critical factor is that non turbo engines have no oil jets to cool the pistons. If you do add a turbo you have to keep the boost so low it is almost pointless. If you’re putting a turbo engine in a non turbo car use the turbo transmission If you dont you run into all kinds of connection issues I am sure of this because I am putting a turbo transmission in a non turbo car what a pain about the only thing that is the same is the bolt pattern from the bellhousing to the block.
Dave S