240D upgrade with an OM617a

[cth350]

Here's a project, taking a 240D with a blown motor and putting an OM617a turbo diesel from a similar vintage 300D under the hood. The car is a few miles down the road from me and the owner would prefer to not sell it if this swap would work well.

What are the pitfalls?
- Will the longer motor fit?
- Engine mounts
- Transmission mount & cross-piece
- Radiator (is there an oil cooler in a 240D?)
- Is the oil filter going to be in the way of anything?
- Will the intake & exhaust manifold setup fit under the hood?
- Is the exhaust adaptable?
- Drive shaft connection concerns? ((Mostly that the current one is too long))
- Wiring differences
- Vacuum setup differences
- Fuel delivery & return

The goal would be start on a Saturday morning and be done by end of Sunday.

-CTH

[vstech]

... wow, IF YOU can start and finish in 48hours, you are good.

[OM616]

Originally Posted by cth350

Here's a project, taking a 240D with a blown motor and putting an OM617a turbo diesel from a similar vintage 300D under the hood. The car is a few miles down the road from me and the owner would prefer to not sell it if this swap would work well.

What are the pitfalls?

- Will the longer motor fit?

Yes, the 123 chassis came with both engines

Originally Posted by cth350

- Engine mounts

Same, you may need to use the 300D arms though

Originally Posted by cth350

- Transmission mount & cross-piece

Use the 300D one

Originally Posted by cth350

- Radiator (is there an oil cooler in a 240D?)

The 300D radiator is a little wider than the 240D one, but it should do ok if it is in good shape. Use the 300D turbo cooler

Originally Posted by cth350

- Is the oil filter going to be in the way of anything?

They are the same as far as I can tell

Originally Posted by cth350

- Will the intake & exhaust manifold setup fit under the hood?

Yes, both engine were avaiable in that chassis

Originally Posted by cth350

- Is the exhaust adaptable?

The 300D has a flexible sectioned header pipe off of the turbo, get one of those. The header support bracket was located in different spots, later models were off of the bell housing, early ones were off of the trans by the cross member. Either one can / will work

Originally Posted by cth350

- Drive shaft connection concerns? ((Mostly that the current one is too long))

Get a 300D front shaft.

Originally Posted by cth350

- Wiring differences

Glow plug relays were different depending on what year the 240D is. Early ones were in the cabin, late ones were on the fender well.

Originally Posted by cth350

- Vacuum setup differences

Same, depending on the vintage, the vacuum pump may have one or two hoses coming out of it, but the engine only needs the vacuum shut off hooked up and that is the same for the 240D.

Originally Posted by cth350

- Fuel delivery & return

Same

Originally Posted by cth350

The goal would be start on a Saturday morning and be done by end of Sunday.-CTH

Not a practical goal for anyone who is not extremely familiar with the 123 model. Even if one sourced all the parts as to have a kit, the lack of familiarity of the vehicles mechanical make up and the differences will slow down the process.

[JB3]

Id say the swap can be performed in a day or a relaxed pace weekend IF you have two complete cars next to each other with all the parts you need and you get lucky with fastners not being corroded or stuck. If you just have the engine and are missing bits and other bits, a couple weeks to a month is a better estimate if you have to source a bunch of stuff.

[cth350]

Spent a few minutes reading older threads on 240D swaps.

Came up with these issues...
- pressure gauge electric vs direct read
- Replace engine mounts on principle
- Engine shock arrangement
- Intake air cleaner (do I have one, hope so?)
- Check flex hoses to transmission cooler
- Rear end ratio & speedo
- A/C compressor & hose routing
- Front spring setup for ride height

New 240D (with 617 swap) owner checking in

81 300d engine swap into a 83 240d engine shock qs and wiring

Interesting parts upgrades for reference:
What part swaps upgrade the 300D?

An older thread that has links to other older threads:
W123 240D engine swap to OM617, and 300D manual transmission swap

-CTH
PS. With regard to the time frame, it's more like the window available rather than the quality of my work. The reality is that have oodles of experience with gas models and less so on diesels, but I do know people.

[ROLLGUY]

Are you using the trans (4 spd) from the 240? If so, many things need to be modified. If an automatic, not as much work. If the engine/trans from the 300 are going in the 240 chassis, things are as others have said- fairly easy with both cars side by side (or close by).

[cth350]

Engine & trans will swap as a unit. -cth

[daw_two]

Originally Posted by cth350

Here's a project, taking a 240D with a blown motor and putting an OM617a turbo diesel from a similar vintage 300D under the hood. The car is a few miles down the road from me and the owner would prefer to not sell it if this swap would work well.

The goal would be start on a Saturday morning and be done by end of Sunday.

-CTH

Have you started yet??? Just checking.

Please document the various issues you run into. I might be doing almost the opposite soon. I've got this car, http://www.peachparts.com/shopforum/mercedes-cars-sale/339723-fs-1981-w123-300d-light-ivory-palomino%3B-memphis-tn%3B-delivery-possible.html, and a local guy has a running 240D, 4speed that is trashed except for the engine & transmission.

Here's one difference that should not be overlooked --- hood pad. The OM617 turbo engines have foil on the hood pad in the area above the turbo. The 240D and 300D NA do not have the foil. If the hood pad is good on the 240D, you probably want to add some type of foil to it in.

Good Luck on the swap.