I got into the MB's last year. Since then I have done a bit to my car to make it my own. I told myself that this is the last car I need to own With proper maintenance it should last forever and just in case I recently bought another 3.0 drivetrain just to sit on deck if anything horrible were to happen. And the 300sd is a car that is timeless and that i could be proud to drive. Well then I laid eyes on the SEC and fell in love. Good lord is that a sexy car! So if this the car I am going to have till I die I need to be totally happy with it so I am duking this decision out.
Ok enough of my own personal battle I will have to figure that out myself. Now the main reason I got into the MB is because it is a well made diesel. I run alternative fuels so because of this I save about $150 or so a month so I can't really justify switching to a monster 5.6 V8 to tool around in so I would like to convert an SEC to diesel. What is involved in this. Like I said I have the motor/trans, my buddy has a few SD's at his junkyard for odds and ends. Is this going to be a huge hassle?
Then of course there is the purist factor, which I am not, but the car I am drooling over right now is a 560 AMG and my god I know that would be fun and to put the pig diesel motor in there would be sacrilege but hey I'm doing this for me.
Well i apologize for going on several tangents here, lets blame it on the a.d.d but would like to hear some tech info and random opinions on the subject. Thanks.

Welcome. This is a goal of mine, too. The SEC is a fantastic looking car and I want one that burns oil.

I can't encourage you to chop up an AMG model that runs. There are enough jalopies out there with straight bodies that you could leave a nice one on the road and use a rough one for your swap. Personally, I think putting a 617 or 603 in a SEC would be a travesty. I am thinking turbo 606 with 5 speed but that's just me.

I can't help you tech-wise, btw. Sorry.

__________________
-----------------
1984 300D 193.5k miles
ASTM-certified B100 bio when able

There should be enough bits in existing cars to get you on the road but some sticking points that come to mind are:

1) SLS = IIRC all SECs have rear SLS which means you'll need an SLS pump or convert the SEC to coil springs and shocks. The easiest way to keep SLS is to ditch the engine you have on deck and get one with an SLS pump in the head such as from an 81-85 wagon. You might be able to attach a tandem (PS and SLS) pump but I haven't heard of anyone doing that in a 617. I mean it's such an easy solution to using a non-SLS 617 in a wagon that I'd expect to have read about it.

2) Prop shaft = you might need a custom length prop shaft.

3) Fuel tank = you might need to customize some fittings if the sedan tank doesn't fit the SEC.

4) Transmission = use a transmission from a W126, not a W116 or W123, so you have the proper speedo drive. If you swap gauge clusters, use a speedo calibrated for the diff.

Sixto
87 300D

Don't forget registration issues - if your state requires inspections for older cars, switching a car from gas to a diesel is usually beaurocratic hell...they make it virtually impossible to do legally.

__________________
TC
Current stable:
- 2004 Mazda RALLYWANKEL
- 2007 Saturn sky redline
- 2004 Explorer...under surgery.

Past: 135i, GTI, 300E, 300SD, 300SD, Stealth

I've helped with a couple gas to diesel swaps and It was easy enough to have the DMV alter the title to reflect the new fuel type.

-Jason

__________________
1991 350SDL. 230,000 miles (new motor @ 150,000). Blown head gasket

Tesla Model 3. 205,000 miles. Been to 48 states!
Past: A fleet of VW TDIs.... including a V10,a Dieselgate Passat, and 2 ECOdiesels.
2014 Cadillac ELR
2013 Fiat 500E.

Some good points. I was not aware of the suspension issue. I will have to look into that.
Beings as it is a W126 chassis, wouldn't the drivetrain location be the same? Probably not, just asking.
Why would the stock fuel tank not work? Did they have in tank pumps and all that other good gasser stuff. Where were they on the coupe?
Well i am pretty sure the spare drivetrain I got was out of a W123 so I may have to think about that.
I forgot about the e check, that might be an issue. The car i am looking at though is an 86 so I think next year it should be exempt.
As far as hacking up an AMG, I would probably try to make it lok like an AMG in the long run anyways since they are so beautiful, this one is priced right and as I said, I'm building it for me so, yes it would hurt but I may do it anyway. I'd probably keep all the originals though just in case.

If you can find the tandem pump from a 350SD/L with ASD or a 190 with SLS / ASD you can hook that up to run the SLS.

-J

IIRC the SEC rides on a shorter wheelbase than the sedans so if the 722.315 or whatever transmission yoke isn't in the same place, sedan parts won't help.

A W123 engine is fine. Trade the transmission for a W126 transmission or just swap the tail housing for one which contains the right speedo drive.

Make sure the gasser fuel level float will survive a Diesel or alternative fuel environment. I don't think a Diesel fuel level float is a direct fit in a gasser tank.

You're not really hacking up an AMG, you're just changing the engine. Do it right and there's no reason it's can't become a gasser again in the future. The conversion should be completely and easily reversible if you keep all the parts and plan and document every step.

Sixto
87 300D

Yes i was planning on doing it proper and keeping all the original parts, especially since from what I hear this car may have a little history.
As I said i am fairly new to mercedes, i know mine fairly well but can someone give me a quick rundown on SLS? I am assuming it is some sort of air ride.

It's a hydropenumatic level control system. Rear only SLS still has coil springs, the fluid only helps. Do some searches, it's a fairly simple system. I wish my car had it and if it did I would fix it rather then replace it with coil springs.

-J

__________________
1991 350SDL. 230,000 miles (new motor @ 150,000). Blown head gasket

Tesla Model 3. 205,000 miles. Been to 48 states!
Past: A fleet of VW TDIs.... including a V10,a Dieselgate Passat, and 2 ECOdiesels.
2014 Cadillac ELR
2013 Fiat 500E.

Well the decision just got a little harder. After feeling what a well tuned 560 feels like, why woud one want to rip it out and put an old clackity diesel in it? Granted I love my 300SD, the way it sounds and feels, but damn. Well i figure I'll run it for a while as is and see if I can stand driving a 18mpg rocket as opposed to a slightly slower veg oil burning pimp car.

And no it is not a true AMG

one doesn't replace a perfectly fine running 5.6l with anything smaller. As for that white car, would you really want to subject it to diesel soot?

Also, the 380sec and 500sec cars for the most part don't have the SLS system.

-CTH
PS. I too have a spare OM617 and was considering a W107 or W126 body for it. The motor is a few inches too tall for the W107.

__________________
- cth350@gmail.com
http://www.111lakeside.com/

HAHAHA I can't believe no one has mentioned this one!

http://www.youtube.com/watch?v=0hd6FEykMwU

I am all for swaps, and I say go for it, I am not sure we need another one like this out there though. Anyway, seriously you could contact them for some pointers.

I mean watch it a couple times (if you can) to at least see what not to do!

__________________
___________________________________________
'86 300 SDL '83 300D Astral Silver/Blue
354k miles.. 326k miles..

http://www.peachparts.com/shopforum/...ine=1310252049

There is a forum member, think his name is ICEFIRE that did a SEC Diesel swap a few years back.
http://www.peachparts.com/shopforum/showthread.php?t=171698


http://www.peachparts.com/shopforum/showthread.php?t=175489

http://www.peachparts.com/shopforum/showthread.php?t=205616


http://www.peachparts.com/shopforum/showthread.php?t=223210

http://www.peachparts.com/shopforum/showthread.php?t=226289

http://www.peachparts.com/shopforum/showthread.php?t=251657

Charlie

__________________
there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works

I remember seeing this a little while ago. No idea why he didn't put a turbo in there, not to mention nailing all over the place and massive revving

__________________
TC
Current stable:
- 2004 Mazda RALLYWANKEL
- 2007 Saturn sky redline
- 2004 Explorer...under surgery.

Past: 135i, GTI, 300E, 300SD, 300SD, Stealth