1977 Mercedes-Benz 450SLC

[Angelfish]

The little 380SL needed a big brother, so over the course of a 1300 mile round trip I brought home a sight unseen 1977 SLC.  Not completely sight unseen, a member of a Mercedes-Benz forum looked at it for me.

 

50,905 miles, but the reason it stopped there is that’s when the badly overheated engine decided it had enough.  That was 1989 or 90 from what I can tell.  An engine with reportedly 125,000 miles was included with the car.

 

Current version of the story is that the dealer pulled the head and announced that the engine was done, and that’s all the information I have in that regard.  And then happened what always happens.  It floated between a couple other people, gathering the door dings common on parked cars until I decided I’d add my name to the list.

 

The car is very nice cosmetically and I’m told the engine swap really isn’t bad.  My experience with fuel injection is limited but the manuals for these cars are very good.

 

More pictures below

 

 

 

 

 

 

 

 

Edited April 9 by Angelfish (see edit history)

[EmTee]

You're in the deep end of the pool now!  Get your tools organized and I'll make some popcorn... 

 

Edited April 6 by EmTee (see edit history)

[Bloo]

Best of luck on the new project!

 

Regarding the pics, I might not be much help because so many are posting from phones these days, but I can tell you what the problem is, and even how to fix it if you happen to be on desktop/laptop.

 

Digital pictures do have a top and a bottom. Some software will allow you to display them any way you like, but they still have a top and a bottom. When you upload them, the forum software will display them as they really are. It has no way to know what you intended, it just starts at the top of the picture and displays it. If the car in the picture is upside down, it cannot recognize that, nor does it have the ability to do anything about it.

 

To fix you must open them in an editor, flip them, and then save them after modifying them. The new file you saved is then a digital picture with the car right side up. A viewer generally can not do this. I use "Pinta" for this sort of editing. It is a lot like Microsoft Paint, which would also work. Any photo editor or graphics editor should be able to do it.

 

If you are on a phone, I just don't know, but the same rules apply. You need to edit the photo and save after editing.

 

Edited April 6 by Bloo (see edit history)

[kar3516]

Here you go…right side up.

 

 

[Angelfish]

1 hour ago, EmTee said:

You're in the deep end of the pool now!  Get your tools organized and I'll make some popcorn... 

 

I just figured out that the seat back locks are vacuum operated.  This thing will be a challenge. 

 

But the clock works.

[Angelfish]

48 minutes ago, Bloo said:

Best of luck on the new project!...

 

...To fix you must open them in an editor, flip them, and then save them after modifying them. The new file you saved is then a digital picture with the car right side up. 

 

Thank you.

 

I did try flipping the pictures and resaving (using a tablet).  Anyway, I'm writing it off to one more hazard of being left handed. 

[Angelfish]

44 minutes ago, kar3516 said:

Here you go…right side up.

 

Thank you.  The pictures might be symbolic of the how this goes.  Upside down before I even get started. 

[Angelfish]

Meanwhile, how do I go about preserving the interior?  Seats are quite nice, minimal dash cracks and the headliner is good.

 

Don’t know if the seats are actually leather or that cast iron fabric they used later on, but they feel a little brittle and I’d hate to put a knee through one.

 

And what do you like to use on the dash to keep the cracks to a minimum?

 

Don’t know if I’m brave enough to attempt a headliner clean.

 

And I think it was someone on this forum that recommended coffee grounds as a deodorizer.  I used it in another car that had mice, Dollar Tree Brooklyn Blend, cost me $1.25 since nothing is a dollar anymore.  Just cut open the top of the bag at set it in the console.  Works great, I use it any car that’s staring to get a little sour.

[EmTee]

For vinyl I've had good results with this:

https://www.amazon.com/3M-39040-Leather-Vinyl-Restorer/dp/B0002NUNM0?th=1

 

 

If leather, I use Lexol

 

[prewarnut]

The wear of dye in the side bolster without destruction of the underlying material makes me think this is not leather but MB Tex. Also supporting this are the crease lines in the seat bottoms that seem superficial and lack of creasing or cracking of the somewhat flattened center pleats. If so it will outlast you. Obviously getting an experienced "eye" on this would be helpful. I have used Leatherique products for cleaning and redying of leather. I differ with their suggestion to completely strip before new dye is applied. I'd first try some spot re-dying (if that is on your mind) as the older/original oil-based dye is much more durable than the new water-based, also imparts the familiar "smell" of German car products of the era, and additionally the removal is just a huge endeavor for small reward over dying over the old in small areas. Being black this can be matched easily and the interior will come out nice. If this is MB tex then the cleaner of choice is probably not too important given the durability of the material. As with all things of new territory go slow and plan.

[Angelfish]

Engine and transmission out.   Not a bad job when someone else already did a lot of the prep work.
 

Next I get to break into the top end of the engines apart and find the best parts to make one that works.

 

 

[Angelfish]

Bore scope into the donor engine revealed 7 beautiful cylinders with crosshatching still visible and 1 with oil on top of the piston. 

 

7 Cylinders look like this

 

 

The oily one was at the top of the stroke.  This is the top of the piston.

 

 

Badly rusted throttle body butterfly.  The one on the car is in much better condtion.

Edited April 8 by Angelfish (see edit history)

[TAKerry]

Dont you know that your not supposed to put straps like that to lift an engine! (JK, sorry couldnt help myself).

 

Good luck with the motor swap. I have always liked the slc's but not enough to dive into one. I have an ML that has computer problems that will make a good project when youre done with this one. And its almost an AACA car.

[Ronnie]

I admire you for taking on the job of bringing an old Mercedes back to life. I've done one that didn't need too much work and that was enough. The way Mercedes does things is too far off the beaten path for me. I had a hard time learning to speak Mercedes. I'm going to stick with American made.

[EmTee]

They are sharp-looking cars; particularly the coupe.  I think the coupe looks better than the roadster with the top up.  Keep your eyes peeled for a set of euro-spec headlights... 

[Angelfish]

2 hours ago, TAKerry said:

Dont you know that your not supposed to put straps like that to lift an engine! (JK, sorry couldnt help myself).

 

Good luck with the motor swap. I have always liked the slc's but not enough to dive into one. I have an ML that has computer problems that will make a good project when youre done with this one. And its almost an AACA car.

Yeah I saw that one about the straps.   Carburetor lift plate is always my first choice, and I really try to avoid using chains, straps don’t cause the damage to valve covers or gasket surfaces.   Just make sure to thread them through the exhaust manifolds so they can’t move.
 

Is that the ML that’s sitting with a non start / random shutdown issue?   The computer sometimes needs reset if the battery dies.   Some combination of tuning the key on and off.  If that’s what it is it’s an easy fix.  If not, well, then it’s not.

[Angelfish]

29 minutes ago, Ronnie said:

I admire you for taking on the job of bringing an old Mercedes back to life. I've done one that didn't need too much work and that was enough. The way Mercedes does things is too far off the beaten path for me. I had a hard time learning to speak Mercedes. I'm going to stick with American made.

Thank you.  I admire people who are smart enough to know their limitations, like Clint Eastwood.  
 

Thankfully these cars have a loyal following and a lot of support, and the factory manuals are very good.   I’ll be relying heavily on that to bring this one back.  

[TAKerry]

3 hours ago, Angelfish said:

Yeah I saw that one about the straps.   Carburetor lift plate is always my first choice, and I really try to avoid using chains, straps don’t cause the damage to valve covers or gasket surfaces.   Just make sure to thread them through the exhaust manifolds so they can’t move.
 

Is that the ML that’s sitting with a non start / random shutdown issue?   The computer sometimes needs reset if the battery dies.   Some combination of tuning the key on and off.  If that’s what it is it’s an easy fix.  If not, well, then it’s not.

I was just trying to be a smart%&^%&^% after the long winded convo about the motor lift. I have no problem at all with what you did, I would most likely have done the same. As for my ML, it runs perfect for about 5 minutes then everything goes wonky. Pull over, turn off and start again and it runs fine. My wife was driving it like this for months without me knowing anything about it. I was driving it one day and it happened to me. She coached me through it. The next day I gave her my spare work truck (expedition) to start driving and parked the benz. I went to a ML oriented forum and it seemed to be a common problem that no one had a fix for. Lots of conjecture but nothing real. The shame is, the motor runs strong, the rest of the car is great but its been relegated to barn find for the last few years.

[Angelfish]

On 4/8/2024 at 5:11 AM, prewarnut said:

The wear of dye in the side bolster without destruction of the underlying material makes me think this is not leather but MB Tex. Also supporting this are the crease lines in the seat bottoms that seem superficial and lack of creasing or cracking of the somewhat flattened center pleats. If so it will outlast you…

Well I did it.  I was pulling the first aid kit pan to access the fuel sender.  This is the top of the back seat, perfectly exposed to the sun, and I poked an elbow into it.  

 

It feels brittle and dry, more what I would expect from leather.   Leaving it alone for now but it definitely needs softened up or there will be more of these.

 

 

[Angelfish]

Untouched first aid kit.  Remarkably comprehensive.

[Angelfish]

Fuel tank looks good.  Needs cleaned but doesn’t appear rusty.

 

 

[TAKerry]

Theres a first aid kit in my ML as well. Never been opened. More manufacturers should put them in their cars!

[prewarnut]

5 hours ago, Angelfish said:

Well I did it.  I was pulling the first aid kit pan to access the fuel sender.  This is the top of the back seat, perfectly exposed to the sun, and I poked an elbow into it.  

 

It feels brittle and dry, more what I would expect from leather.   Leaving it alone for now but it definitely needs softened up or there will be more of these.

 

 

That looks like leather. Using Leatherique's Pristine Clean and Rejuvinator might help. The Rejuvinator is an oil and if this dry as in your picture it will likely soak it up well and help to soften.

[Angelfish]

Should have it running in a couple weeks.   
 

Edited April 19 by Angelfish (see edit history)

[Angelfish]

And so it begins.  I finished up some other things so now I get to spend some time on the SLC. I am going to need some help, this whole European thing is, well, foreign to me.

A brief recap, the original engine was overheated and seized at 50,000 miles. I refer to this engine as “50.” A replacement engine claiming to have 120,000 miles came with the car. This engine is called “12.” It was clearly left out in the rain and the intake and throttle body are in poor condition, but the cylinders look very good. I have not attempted to turn it as there may be debris that made its way in through the intake.

The engines are similar but not identical. I will need the two to make one. Pictured below are the obvious differences I have observed between them. I assume that 50 is a later production as it has the segmented exhaust manifolds and a slightly cleaner arrangement in the thermostat housing.

Current plan:
Use the bottom end and heads of 12, including oil pan. I am currently not planning to do any work on the rotating assembly. I will pull the heads and clean out the cylinders, replace valve seals, clean or replace injectors, and whatever else is necessary.

I will use the intake, throttle body, fuel distributor and exhaust manifolds off of 50. (Original engine). I assume the water pump was run dry so I make not want that one. The smog pump is seized and I would like to eliminate as much of the smog system as possible. I will probably leave the cat for simplicity sake, the exhaust is in good condition.

And I expect to replace the timing chain and related bits. Setting the timing when this is done will be an interesting experience for me.

 

[Angelfish]

[Angelfish]

[Angelfish]

 

Edited May 8 by Angelfish (see edit history)

[Angelfish]

[Angelfish]

[EmTee]

I think (whatever that's worth) that you have the right idea.  I would use 12's long block and dress it with the accessories from 50.  The immediate concern I have is whether the intake & injection components are compatible with 12's heads.  If there's an issue, you may be forced to use 50's heads on 12's short block.  If that happens you'll need to have 50's heads reconditioned and milled to remove any distortion from the overheating episode.  Hopefully the 12's long block can be used and fitted with the other pieces that came in the car originally.

[Steve_Mack_CT]

Fish assume your asking the BW 107 crew the same questions?  Looks like a good approach - discard nothing at this time, you never know..

[Angelfish]

2 minutes ago, Steve_Mack_CT said:

Fish assume your asking the BW 107 crew the same questions?  Looks like a good approach - discard nothing at this time, you never know..

Yup, and once again the AACA guys have been more helpful than the MB guys.   I was hoping to learn if I’m going to run into compatibility problems between the two engines before I get too carried away.  They’re both M117 450s so I assume Im ok, but it would be nice to know for sure. 
 

I need more shelf space but so far all parts are accounted for.

[Steve_Mack_CT]

Bummer on the lack of help!!  I have no manuals or partsguidesforthecast iron engines - wish I could help...

[Angelfish]

Big brother, little sister.

[Angelfish]

There is a reasonable chance that I’m making this harder than it needs to be.  Engine 12 was complete but had gotten water down the throttle body and fuel distributor.   The intake from 50 was in very nice condition but I also have to consider that it may have been warped when it overheated.

 

If I were to have 12’s intake soda blasted, the only parts I’d need from 50 are the fuel distributor, fuel lines and throttle body.   I can have the heads done, buttoned up and bolted down before I need to do anything with the intake.

 

You have to get up pretty early in the morning to put one past me.

[Angelfish]

On 4/9/2024 at 8:14 AM, EmTee said:

They are sharp-looking cars; particularly the coupe.  I think the coupe looks better than the roadster with the top up.  Keep your eyes peeled for a set of euro-spec headlights... 

I just wanted to thank you for all your input and you’ve also helped with my 57 Buick.  The paint shop expects to have it done in September, with any luck the SLC will move under its own power by then and maybe I can get the Buick well along over the winter.  Best laid plans and all that.

 

I’m almost afraid to admit that I like the American headlights (not so much the bumpers), I think it goes back to 1979 when my Dad bought a new Audi 5000, alpine white with the blue interior.  
 

We drove that car to California, Alaska, Washington, Arizona, Canada, the Midwest.  My Mom had a 50 mile round trip commute every day through deer infested roads and 55” of annual snowfall.   Did hit a couple deer but always got it fixed.  She adored that car and credits it with saving her life a few times on some very bad roads.  Finally sold it in 2000, good running and cosmetic condition all original one owner with almost 400,000 miles.  Always used Arco graphite oil.

 

It had the American round headlights.  

[EmTee]

6 hours ago, Angelfish said:

I’m almost afraid to admit that I like the American headlights...

I'm not offended by them either, though many do prefer the euro style.  A friend of mine has a euro-spec SL with the composite headlights and a stick.  It does give a cleaner look and if nothing else, stands out against the other 95% with sealed beams.  I'll say again I like the look of the SLC and personally, I'd prefer having one over an SL.  But then again, I also like the looks of the 630 CSi... 

[Rivguy]

About the seats, they do appear to be leather. I would try to clean them gently and carefully. Then I would apply a slightly thinned down (with a bit of water) coat of Lexol, then cover with cloths that are wet with the same mixture. I'd keep the cloths damp and let them sit for a couple of days. The hope would be that the leather will absorb some of the Lexol over time. My XJS had a drivers seat that was cracked, and the leather was like beef jerky, it never did soften up. Good luck with your project. 

[Angelfish]

On 5/9/2024 at 11:38 AM, Rivguy said:

About the seats, they do appear to be leather. I would try to clean them gently and carefully. Then I would apply a slightly thinned down (with a bit of water) coat of Lexol, then cover with cloths that are wet with the same mixture. I'd keep the cloths damp and let them sit for a couple of days. The hope would be that the leather will absorb some of the Lexol over time. My XJS had a drivers seat that was cracked, and the leather was like beef jerky, it never did soften up. Good luck with your project. 

Thank you.

 

I’ve been meaning to follow up on the seats.   I got some saddle soap from the feed store and have been going over the seats once or twice a week.   So far they a looking really nice.   I'll need to repair the piece I cracked in the back seat but I think it will turn out well.
 

I do like the idea of soaking the cloths, I'll give that a try.

 

Edited May 11 by Angelfish (see edit history)