W108 - Bouncing some project ideas around

[mosu]

With the salty Toronto winter here, it's time for the Benz to go in hibernation...under the surgeon's knife, really.

I wanted to bounce some build ideas. My goal is to do a rolling restoration of the car over the next 3-4 years. I'd like to be drive-able during the summer and receive some remedial attention during winter. I have my first kid coming in May which means that the first batches of work will be outsourced. Both my wife and I like road trips wafted along by a burbly V8. In a few years, I`d like this car to take us on a family trip of a lifetime, reliably and comfortably.

So without further ado, I want to get some suggestions on how to proceed.

Current condition:

100% original, has probably seen winter in its youth. Parked in 86, brought out last year and gotten to a painful drivable state. Carbs are worn and missing parts, engine is strong, even compression but leaks at almost all gaskets. Suspension rubbers are very old. Rear axle leaks at the pivot bushing. Body has lost the undercoating on rear section and has surface rust on underbelly. One spot in the rear floor pan feels mushy, the rest are solid. Trunk has surface rust. Paint is an old respray but looks good save for a few dings. Interior is musty, but in excellent condition. Door seals, all wood, dash, in good condition. Needs new heater dials and core is disconnected (assuming a leaker).

The engine has to come out for a reseal. Ditto for the transmission and rear end. At that point, a shop can probably strip off the undercoating, treat starting rust and reseal with modern stuff.

For the engine, I figured I have a few choices:

1) Tear down, inspect and refresh current motor. Replace Zeniths with Webers or professionally rebuilt Zeniths.

2) Replace with fuel injected M130. Get a few ponies and some potential hassle from sourcing old FI components.

3) Source a 3.5 or 4.5 V8, refresh and drop in. Would my 4 speed manual bolt up to it?

4) Source an M110 FI motor from an early 80s car and get more power plus more modern FI. This sounds like the most involved swap.

Start driving at this point and address the interior in smaller sub-projects.

Thoughts, ideas, cautionary tales?

Cheers!

[JeffreyNMemphis]

Hi Mosu,

What year is your W108? Which motor do you have in it now?

Are you planning on keeping the car? Do you care about value increase or decrease after projects?

Do you have pictures? We love pictures!

[JMela]

I too have new(ish) baby and carb'd 108 with soft trunk wells.

Get as much done as you can before the kid arrives - progress slooooows somewhat after.

I rebuilt my Zeniths and have them working pretty well. That carb switch in front of the front carb kept me from making the switch to Webers.

[napster]

For the musty smell cut up a dryer fabric sheet into two and place one half under each of the front seats. This will help eleminate the musty odor.

I learnt this trick from a friend who sold used cars. If the smell is too strong from the dryer sheets then use less or more.

[Tomguy]

So I assume you have a 250S or 280S based on the description. Sadly, these are the least desirable 108s. However they are a great car and a great platform to build off of.

First and foremost, what year is this? I always saw info from old board members (Such as psfred whom I haven't seen in years now) that something like pre-68 or pre-69 vehicles couldn't easily accommodate a 116/117 engine due to their brake booster location which was later moved. I've never been able to verify this myself so I assume it to be true unless otherwise seen.

That being said, the manual you have will not bolt up to an M116/117. However, that would not deter me from putting one in. An aluminum-block one (3.8 through 5.6) would net you a much lighter engine, so you wouldn't need to swap front springs out to be able to have the proper factory-intended height and handling. Since you sound like you want a V8 - and who could blame you? - you'd probably want the 5.0 or 5.6. I'd personally do a 5.6, with a nice true dual exhaust, but keeping it in the "Spirit" of OEM with 2 tailpipes on each side (for a total of 4 chromed exits).

If you kept an MB engine under it, it wouldn't be likely to hurt resale, even if not original. Most buyers of these now are buying to modify and not for originality. As a result, you have a pretty desirable mod already done. If you were a huge stickler, you could even D-Jet or Megasquirt the 5.6, use the older-style valve covers, distributor, intake manifold, cleaner, etc. from a 4.5, and nobody would even know simply looking under-hood that it wasn't a stock 4.5.

[mosu]

Sorry, I filled the car info in the wrong spot - signature fixed.

It's a 1968 280S, twin Zenith craptastic goodness. Its nickname is the Demon Car as it behaves like it's utterly possessed. Some days it will start and run like a champ...others, it's crank, crank, crank, sputter, sputter, sputter. It blame the Zeniths because it's what the cool kids do

If I undertake the project, I wouldn't lose sleep on the value. Doing it so I can have fun. Already have more $ in it than it's worth on the market.

To lump some answers in one response:

Don't care about Zenith vs. Weber as it's a manual car. If the M130 stays, the better drivability choice wins.
I'm not set on a V8, just slightly partial to it because burble, burble, vroom! I also love the sound of high revving, butter smooth I6s, so I'll go with the "biggest benefit to the butt dyno for the buck" on this one. I'd prefer to keep the manual tranny if I can help it. I might consider a road rally in it one day. Maybe.

Because I live in a condo and the baby's coming in May, I've accepted that someone will have to do the heavy lifting. If I keep it, I'd like to strip off the undercoating and stop the rust before getting into heavier $.

If someone is close to the Toronto area and wants to join me in this project, I'll happily skip the shop part

Exterior pics, more to come...

[mosu]

Undercarriage shots, counter-clockwise from the driver's side around the car...

[mosu]

More undercarriage shots (the 5 picture limit sucks).

[mosu]

Under hood shots. Some people call it dirty. I prefer factory original.

That K&N sticker is legit. Because your chain doesn't rattle if you can't hear it.

[mosu]

Seats and interior are not too worn.

[mosu]

Lastly, the funk in the trunk. Doubles as tool storage. Condo life...

Thoughts, impressions?

[mosu]

Forgot to add...original sales brochure in French. Car is originally from Quebec.

The manuals, however, are only in English. That would not have flown today.

[vandor]

Looks pretty nice! I'd keep the I6 and manual trans, as manual trans w108 are not that common.
I have a patch panel for the right side trunk floor for sale if you need that piece.

[mosu]

Thanks, Vandor, I'll keep your offer in mind for when I address the trunk. My metal is pretty solid. Looks a lot worse in pictures. It really is a good base car, and in excellent condition for our climate.

Reading, reading, reading, I have settled on a game plan. I will refresh my existing setup. I want to stretch the budget as much as possible since I won't be doing most of the work.

To that end, more questions:

1) If the engine comes apart for a reseal, are there reasonably avenues to get more power? Thinking cam regrind, port work? What's worth the money and what isn't on a carbed M130?

2) Fuel delivery will stay carbed for now. The Zeniths are missing some pieces such as the anti-stall diaphragm and are in generally poor condition. I'm leaning towards a set of Webers, but can't seem to find consensus in past threads if they are a definitive win over the Zeniths or an improvement because someone's setup was worn. Any final words?

3) What are key things to consider "while I'm there" if the driveline comes out? New fuel/brake lines, clean and reseal fuel tank, rear axle bushings and seals...anything else?

4) If the gear box shifts OK, but feels a just a tad crunchy, is there anything I should do while it's out?

That's what I have for now...she'll stay original and I'll contemplate a bigger engine down the line when I have more time/$ for it.

Cheers!

[JeffreyNMemphis]

Hi Mosu,

Nice Car! It looks very good. I like your current thinking on what to do.

Have you heard of POR-15? I brushed it on to some rusty flimsy metal on The Bullet and when it was dry it felt like hardened steel. I would recommend it for the jack point you showed and any other area you want to preserve.

If Weber carbs don't make a dramatic change, I would rebuild the Zeniths.

Are you missing your floor mats? Your photo shows the driver side carpet without a mat. I bought a set for my 2000 E430 at the dealership for $130.00 which was shockingly reasonable. My friend paid $75 for W202 Chassis mats at the dealership.

The car is almost 50 years old. I would focus on the condition of rubber bits, especially those that carry fuel. Also, if the windshield seals (front and rear) are original they may leak and ruin your wood dash. Our host sells window seals at a reasonable price.

The heater cores also seem to leak eventually, it may be a good idea to inspect and proactively treat for corrosion. The heater core never picks a good time to empty its liquid contents into your car's interior.

Have you done a compression test on the motor? It may reveal issues with valve guides, valves, etc. While you are in there I would inspect the timing chain and chain tensioner. Inspect fan belts and hoses. Check water pump for play.

I like the idea that you are keeping the car largely original. When I see a Mercedes with a small block Chevy motor or Gullwing doors I hope the owner will be happy to keep it forever. Your car was beautifully designed and engineered for solid performance and safety. They are becoming more and more rare as time and decay reduce the numbers of Mercedes Sedans on the road.