W123 OM648 Project - Page 2 - PeachParts Mercedes-Benz Forum

VaiFanatic · #1 02-20-2022, 11:32 AM

Quote:

Originally Posted by BirthdayBenz

Compare to the 617 and even 603, this engine runs amazingly smooth. I was excited to hear the turbo spool up driving the CDI up the hill of my driveway. I think this would be super cool in a w126, but I would think manual conversion could be more trouble than its worth. The transmission I have was very inexpensive. Also being from a diesel car it has better gearing for the CDI engine compare to something from a gasoline car. But also, the adapter plate kit is the most expensive part of this swap.

This swap would probably be simpler in the w126 chassis than it's going to be in the w123.

I've thought of doing this in a W108 also. Some sort of ratty looking one making 500hp

The manual conversion is definitely worth it for me. I HATE automatics. I've already made a manual pedal set by cannibalizing the parts from a W201 pedal box for my 500SE, and can do the same again fairly easy enough.

My '96 F-350 that I bought from the original owner was on its third E4OD automatic, and I quickly swapped it out for a ZF-5 with a transfer case to also make the transition from 2WD to 4WD. I've also completed an auto to manual swap in my '98 Durango with the 5.9 Magnum V8. No manual swap isn't worth whatever troubles it may bring

I can fabricate a lot of what's needed, but my shop time has been reduced by increased work (I work IT) and the fact that I just became a dad last month. DieselPump's kits are reasonably priced (compared to Rennsport, anyway) and I wouldn't mind just paying the piper to get the job done a little quicker.

I am thinking, however, for the sake of not having to deal with too much in the way of electronics, going with a 606 to replace the M103. If my 170S (4cyl) were a 220S (6 cyl), with the longer hood/engine bay, I'd stuff the M103 in it, haha.

The goal would be a peppy, long-wheelbase sedan, that can get fantastic mileage and do well on long trips across the country.

BirthdayBenz · #2 02-20-2022, 07:42 AM

I decided on an OM606 pan. Counting bolts on the M104 pan, the pan dropped for the sump one bolt hole before the 606 pan which would have set it forward about 50mm. I think I have a pump coming from one of the clubgwagen guys. Fingers crossed there. The accessories and drive belt on the CDI engine are very close to front the edge of the pan. Maybe only 60mm out. I sure would like to use the puller fan from the CDI but not sure if I'll have room. Wonder if I could reverse the thing and run it as a pusher fan on the other side. I had a parallel flow condenser and sanden compressor on the 617. Not sure if that is going to stay. I'd forgo AC for a CDI swapped W123 anyhow so it's not a big deal.

w123fanman · #3 02-20-2022, 09:17 PM

I'm considering an OM647 for a W123, seems to be closer to the spirit of a 300D. Was your weight with oil in the engine and trans?

Either way, very interested in how this turns out. I will pick up a 612 harness for this build.

BirthdayBenz · #4 02-21-2022, 07:16 AM

Quote:

Originally Posted by w123fanman

I'm considering an OM647 for a W123, seems to be closer to the spirit of a 300D. Was your weight with oil in the engine and trans?

Either way, very interested in how this turns out. I will pick up a 612 harness for this build.

The OM648 engine with all accessories and oil was 555lbs. With the 722.6 attached the whole thing was 745lbs. I've not yet attached the flywheel, adapter plate and BMW transmission. I plan to post weight differences between the OM617, 4speed, 722.6, OM648 and BMW trans at some point after I have the OM648/BMW trans assembly together.

Won24 · #5 02-21-2022, 06:16 AM

I'm thinking about doing this same thing with my w124 for the same reason. OM606 is too expensive, and if be happy with just the factory 648 power (although I'm sure I'd end up with a little more power. I was looking at using Baldur's ECU the DID1 as it comes with a base map, although black smoke's may as well.

Let me know if you need anything 3D printed, not sure what that would be but I'm happy to help out. If you're nearby (I'm in SoCal) I'd be happy to lend a hand too!

BirthdayBenz · #6 02-21-2022, 07:26 AM

Quote:

Originally Posted by Won24

I'm thinking about doing this same thing with my w124 for the same reason. OM606 is too expensive, and if be happy with just the factory 648 power (although I'm sure I'd end up with a little more power. I was looking at using Baldur's ECU the DID1 as it comes with a base map, although black smoke's may as well.

Let me know if you need anything 3D printed, not sure what that would be but I'm happy to help out. If you're nearby (I'm in SoCal) I'd be happy to lend a hand too!

The blacksmoke ecu comes with a complete tune. Not sure if I'll need to data log and work with them remotely once its installed to workout any issues. It's a stock ecu from an OM613 that has had an updated map and a bunch of things EGR things turned off.

I'm in South Carolina, I'll definitely shoot you a PM if I find something I need printed!

BirthdayBenz · #7 02-21-2022, 07:37 AM

My Parts from sendcutsend arrived. Looks like I designed them correctly as all the holes line up!

I need to clean the inside of the intake and tap the holes for the swirl flaps that I removed and plug them with bolts. Then the intake can go back on along with the OM613 engine harness.

BirthdayBenz · #8 02-25-2022, 06:26 AM

Not much progress to show in the past few days. Just cleaning things. Cleaning nasty EGR gunk... scrubbing, brushing using the steam machine and making a mess. Scraping the oil pan gasket which is the most stubborn gasket I've ever encountered. I soak it in WD40 every so often then scrape a little soak it repeat...

I tapped the swirl flap holes to M12x1.5 and then realized I only had M12X.1.75 bolts around so I proceeded to order bolts.

At least having ordered bolts they're all uniform. I had a bunch of copper crush rings around from oil changes as I never remove the drain plug. I have an oil extractor. Glad I kept them around.

More cleaning for now and waiting on gaskets from Mercedes.

BirthdayBenz · #9 03-01-2022, 02:39 PM

Looks like the OM606 oil pump does not fit on the OM648 block.

606 has a square outlet where as the 648 has a round one with rubber gasket. Looks like I'll be looking for another pump.

wschotty · #10 03-02-2022, 11:06 PM

Nice project!

Check out post 58 on this thread for some others who have been down this road:

OM606 rear sump oil pan?

BirthdayBenz · #11 03-03-2022, 08:17 AM

Quote:

Originally Posted by wschotty

Nice project!

Check out post 58 on this thread for some others who have been down this road:

OM606 rear sump oil pan?

Thanks! I think I found that post when scouring the internet but didn't thoroughly read it. Having read it now looks like they just used the o-ring even through square vs round mating surfaces exists. Makes me fell more comfortable about doing that, which was my plan.

BirthdayBenz · #12 03-03-2022, 02:22 PM

Another unforeseen issue....

The bolts from the OM648 pump (right) are too short to work with the OM606 pump. I was able to find bolts from my old M113 oil pump (left) which appear to be the correct length.

BirthdayBenz · #13 03-08-2022, 09:49 AM

I installed the pump and windage tray this morning. Two of the main bearing cap bolts needed to be swapped to allow the windage tray to bolt on. That extra 90 degrees post torque always stress me out.

Then when trying to mount the pan I've ran into a larger issue. The OM606 pan doesn't clear the OM648 flywheel.

The OM606 flywheel must be a smaller diameter. I think I'm going to find a machine shop who will cut 1/2in off the back of the pan so it clears the flywheel. I think finding an OM606 flywheel and then figuring out the starter situation plus crank position trigger for the ECU will be more problematic than just cutting the pan. I have the large adapter plate for the manual transmission so I'm not worried those two bottom bell housing bolts.