Engine swap dilemma...should I? - PeachParts Mercedes-Benz Forum

Johnhef · #1 11-19-2005, 07:32 AM

Ok heres the deal, my 380SEL has been sitting for almost 3 years now since I took it apart, I'm in no real rush to get it back together although I did convert it to a double roller chain and have the heads back on it but thats it. The engine and trans are still out of the car.

I have to make a decision today if I want a 603 engine otherwise its getting crushed with the car.

Basically the general idea is to make my own SDL out my nice and very dust covered SEL. The donor car is an 87 300D and my recipient is an 82. Does anyone forsee any problems? I'm going to try and get the whole car so I can swap out any other parts needed, such as harnesses and whatnot.

Am I crazy or does this sound doable? Losing the 380 engine isn't a big deal, I still have two 560's of which I'll probabaly keep one and I'd like to have a nice big S Diesel anyways.

Brian Carlton · #2 11-19-2005, 09:08 AM

John, I can't comment on any issues of putting a 603 into an older W126. At first glance, it seems like it should fit without any problems. The only question would be slight differences in the body and the mounting points on the older vehicle.

But, if you found a decent 603, I strongly advise you to get it. That's a valuable engine, by itself. Even if you don't do the transplant, the engine is worthwhile to have.

I might even need one myself, soon.

Johnhef · #3 11-19-2005, 09:29 AM

how about the transmissions? Without side by side comparisons I'm unsure if I can just slip the later trans in. I had the 380's rebuilt and the status of the 603's is unknown. I'm going out to the yard today to try and start it and see how it runs. All I know is the car came from a shop where the owner couldnt decide what to do with it or couldnt pay the bill. I dont know what it was in the shop for yet.

andmoon · #4 11-19-2005, 09:42 AM

How do you go about getting a state inspection?

t walgamuth · #5 11-19-2005, 10:48 PM

seem to me if you had two complete cars you surely would be ok. just swap everyting that is different over.
from the radiator to the rear end and the speedo.
some would say keep the 380 rear end. i guess i would prob try that out myself before changing.

tom w

sixto · #6 11-20-2005, 01:26 AM

Should be a fun project. About the biggest customization will be fitting the W124 oil cooler into a W126. I'm not sure if the W124 air cleaner and airflow meter (if necessary) will fit a W126 but I'm sure it's not difficult to find SDL pieces in a wrecking yard.

Sixto
87 300SDL

MS Fowler · #7 11-20-2005, 05:56 AM

I don't believe the Maryland State Inspection would prove to be a problem. The emmissions inspection even has a spot to check that you converted from gas to diesel power--and diesels are currently exempt.

t walgamuth · #8 11-20-2005, 07:45 AM

prob has an oil cooler too. i wouldnt be surprised if it just bolts up.
hoses may be different. could prob get used or have fabbed or just buy the parts from parts supplier.

tom w

#9 11-20-2005, 04:54 PM

Have fun playing with the ignition and being able to shut down the car.

Remember...diesels use vac...gas uses electricity

Keep us updated

phidauex · #10 11-20-2005, 06:04 PM

Quote:

Originally Posted by Brandon314159

Have fun playing with the ignition and being able to shut down the car.

Remember...diesels use vac...gas uses electricity

Keep us updated

The shutdown shouldn't be a problem. You can get a vacuum changeover valve (there is even a mercedes one, if you want to go 'all original'), and have the ignition switch activate and deactivate the valve that supplies vacuum to the shutoff. Its like when people install remote starters on older diesels, they do the same thing.

Anyway, sounds fun! Good luck with the project.

peace,
sam

Johnhef · #11 11-26-2005, 12:32 PM

Well after this morning looks likle I will be undertaking this project.

They did indeed save the car for me- I will be bringing home the entire car so I can have everything on hand needed for the switch.

Looks like I may just have to do a m103 water pump in exchange for the engine if I'm lucky. Nothing beats a nice trade

my126benz · #12 01-17-2006, 12:14 AM

Can you put a 617 diesel engine from a 82 300 SD 126 into a 88 420 SEL 126? The chassis are the same and i figured besides the engine and trans that the ignition, radiator, instrumet cluster, fuel tank and possibly rear end would have to be changed. Any one have any comments?

t walgamuth · #13 01-17-2006, 09:06 AM

is to try to stay with the same year chassis if possible. i would worry that some wiring harness issues would crop up. but if you have both cars complete you should be ok.

tom w