617 into 115 Swap Questions - PeachParts Mercedes-Benz Forum

luketmarx · #1 12-23-2018, 11:08 AM

Hi All,
I’m verly slowly doing an engine swap. As I’m removing the donor engine from an ‘84 300SD, I’m taking lots of pictures and wondering what certain things are, and if they need to be kept with the engine or not. I’m hoping to post these items and welcome any feedback. I’ll be posting videos in a shared google photos link because the mobile platform of this website won’t let me upload pics. Thanks!

Question: i have vacuum lines going to my turbo and EGR, coming from some sensors. I know I can delete the EGR, but what about the vacuum going to the turbo? And the sensors, will I need to integrate them into my w115? Thanks!
https://photos.app.goo.gl/YcDPxMbnC3eGRbcq8

t walgamuth · #2 12-23-2018, 12:34 PM

I don't know the answers to your questions. I believe you need to look carefully around the sides of the engine to determine fitment problems. The 115 engine bay was designed before AC was so common and it is very narrow up front. The 85 engine was designed for all the accessories to be mounted at the front of the engine so you'll have some interference problems to overcome, I believe.

luketmarx · #3 12-23-2018, 03:56 PM

I’m not so worried about fitment, I’ve beeen in contact with someone who did a similar swap. I know I’ll need to make some ‘adjustments’ but I’m planning for that. I’m just not super familiar with a lot of the vacuum controls on the 617-needing to learn what each thing does and if I need it or not..

MB140300SD · #4 12-23-2018, 07:14 PM

The major problem with your swap is the oil filter is going to be in the way at the back of the engine. You are going to have to either somehow relocate the oil filter housing, or cut out the supports and/or part of the firewall.

luketmarx · #5 12-23-2018, 10:59 PM

There are aftermarket oil filter adapters available, thats easy. The hard part is actually going to be not enough clearance for the lower sub frame, going to have to do some cutting and welding there. Right now I’m concerned about the pneumatic/vacuum lines and sensors connected to the turbo. Needed? The sensors are connected to the car via electrical connections. If that system is needed, what parts will I need to harvest?

junqueyardjim · #6 12-24-2018, 10:06 AM

Well, look it over, take pictures and it will go good, except for the problems previously mentioned. Regarding vacuum, there is none to the turbo. The only vacuum used on the 617 diesel is for the engine shut off at the back of the injection pump.

junqueyardjim · #7 12-24-2018, 10:17 AM

There is an over boost pressure air line from the turbo (rear of the manifold) to a controller on the firewall and from there is goes to the ALDA device on the injection pump. The idea for this device is that if the turbo produces to much boost the control will limit the amount of fuel. On mine, I used that line to signal a boost gauge I put in the dash. I imagine that once in a while a situation will develop and make to much boost, but I watch mine, and high is 10 PSI, and I like that better then the automatic controller.

sixto · #8 12-24-2018, 12:02 PM

In most 617 passenger car applications engine vacuum is used for brake assist, transmission, engine shutoff, EGR, door locks and HVAC vent selection. There’s a couple of nipples along the brake booster line that supply the other consumers and a reservoir so the locks have a few cycles with the engine off.

Sixto
98 E320s sedan and wagon
02 C320 wagon

ROLLGUY · #9 12-24-2018, 12:34 PM

Your '84 SD engine probably has an ARV equipped turbo, and has a vacuum line going to it. You can remove the compressor side housing, and replace it with a non-ARV housing ('83 and earlier). Or you can just remove all the vacuum related items except for the shutoff, brake booster, locks, and trans modulator. Those are the only vacuum consumers needed. Of course no vac is needed for the trans modulator if you are running a manual trans.

Also, your engine may have a rack position sensor on the IP. It is not needed to make the engine run in the W115 chassis, and can be deleted (wire cut) or just left unhooked.

luketmarx · #10 12-27-2018, 10:23 PM

So if my turbo is equipped with an ARV housing, with a vacuum line going to it...what exactly does that do? And if I just keep my ARV housing but cut vacuum/control to it, what would happen?

ROLLGUY · #11 12-27-2018, 11:31 PM

Quote:

Originally Posted by luketmarx

So if my turbo is equipped with an ARV housing, with a vacuum line going to it...what exactly does that do? And if I just keep my ARV housing but cut vacuum/control to it, what would happen?

They have a tendency to leak boost, as the rubber parts inside go bad. You could also just remove the housing and plug all the holes with something.

sixto · #12 12-27-2018, 11:43 PM

In the case of the 603 Garrett turbo, I pressed a freeze plug into the ARV inlet. I left the ARV housing sealed and in place because the port to the compressor inlet was an odd shape to plug.

If your turbo has the same trim as a non-ARV 617 turbo, maybe you can swap compressor housings. I get the sense it won’t be that easy since the ARV turbo is positioned differently.

Sixto
98 E320s sedan and wagon

ROLLGUY · #13 12-28-2018, 11:18 AM

Quote:

Originally Posted by sixto

In the case of the 603 Garrett turbo, I pressed a freeze plug into the ARV inlet. I left the ARV housing sealed and in place because the port to the compressor inlet was an odd shape to plug.

If your turbo has the same trim as a non-ARV 617 turbo, maybe you can swap compressor housings. I get the sense it won’t be that easy since the ARV turbo is positioned differently.

Sixto
98 E320s sedan and wagon

Yes the port on the ARV housing is weird, but I did a similar plugging of it with a rubber plug and silicone (IIRC). Of course the best way is to replace the housing as suggested in post #9. The ARV and non-ARV housings are interchangeable.

gmog220d · #14 12-28-2018, 08:03 PM

What year and model W115 is the engine going into?

If the car was a 4 cylinder diesel perhaps you could use the gorilla knob to control your glow system and start it, just like it was with the original engine. If the car was a gasser you would need to come up with a way to control glow and then use the key to start. Full manual control of glow with a button on the dash or console might be simplest.

For stopping the engine the ignition switch from neither gasser nor 4 cyl. diesel has a integral vacuum switch so using it to control a vacuum signal to the shut off valve on the IP is out. But either ignition switch could possibly be used to send 12V to a solenoid valve that prevents vacuum passing when energized, when the key is in "run" position.

If the car was a 5 cylinder 300D then you probably have all this covered with the existing ignition switch that's in the dash.

The only engine sensor the car is looking for is the temp sensor in the cylinder head, used for the temp gauge in the cluster (could be different for W115 300D). The '73 W115 I had for years had a non-electric old school gauge with a probe that went from the cluster to the cylinder head. The '74 I have now has a electric temp gauge setup, and maybe the later electric sending unit like in your '84 engine would work properly connected to the later style W115 electric gauge. If not swapping the sending unit from the original engine would solve that problem.

gmog220d · #15 12-28-2018, 09:04 PM

Quote:

Originally Posted by luketmarx

The hard part is actually going to be not enough clearance for the lower sub frame, going to have to do some cutting and welding there.

M-B put a OM617 into W115, the first 300D. I'm relatively certain there's no need to modify the sub frame, unless there's a difference in the upper oil pans between 617s installed in W115 vs other chassis that had 617s.

What are you using for engine support arms? If you were planning on making them you can avoid the hassle by sourcing a pair of factory arms. You might also require a different transmission mount bracket, and a different length front driveshaft section. Shift rods could also be different lengths.