Restoring an old 180db Mercedes Benz (Ponton) from 1960. A barn find ?

[anyweb]

they tried diesel and other lubricants and force, none helped, so it must come out to free it from below, i'm not an engine guy but I understood what he showed me today (I should have taken some photos), and yes it needs to come out...

hopefully then they can fix the engine properly and I can get some good news... aside from the bill.

 

[Frontstep]

A million years ago atf and acetone left soaking used to help, you can't bash them too much because it damages the rings.
Chances are when they are seized in damage has been caused.
Old cars are usually restored by enthusiasts in full DIY mode who are blind accountants and dreadful time keepers, endless hours spent restoring and finding parts are soon lost in misty memories.

 

[om613]

The head looks poorly, the two cyls with all the carbon correlate to the pitted bores I mentioned.
These projects always end up costing much more than anticipated.

Which OM engine does it have? A used one transplanted might be the most cost effective option here but I expect they'll be rare.
Once it's out, you could probably strip it down yourself, post up the photos, and we can comment on wear / damage?

 

[anyweb]

hi Om613,
it's this one according to the wiki

1.8 L OM636 Diesel I4

and I'm pretty sure it'll be near impossible to find a good replacement engine, you are making me more concerned now with your comments, so do you think it's in terrible condition ? can't it be cleaned up ?

 

[rifiki]

Wow... don't get despondent about climbing hills anyweb - it will be such a superb classic when it's finished. I'm really strucj by how solid it looks under the (missing) bonnet. I think this really shows Merc engineering as it was in the old days.

Not like to day, I have a W209 CLK. 1961-68 I thashed a 190 around East and Central Africa.

 

[om613]

hi Om613,
it's this one according to the wiki

1.8 L OM636 Diesel I4

and I'm pretty sure it'll be near impossible to find a good replacement engine, you are making me more concerned now with your comments, so do you think it's in terrible condition ? can't it be cleaned up ?

The head will clean up fine. The pictures, from what I could make out, show the front two cylinders looking corroded or scored, so it'll have to come to bits. It can be repaired, I'm sure.

Just had another look at the photos. I reckon the bores have been 'DIY cleaned' with oxide paper or something.
I think they'll need re-boring, too far gone for honing.

 

[anyweb]

hi Om613 can you please explain the difference between honing versus boring cylinders ? I have honed brake cylinders before, is boring more extreme or uses different tools ?

 

[Ken_R]

Boring cylinders involves removing metal and then the expense of purchasing over size pistons/rings. You seem to have a capable mechanic. Be guided by him.

Whilst the head is off, have it checked for being flat.

 

[om613]

Ken beat me to it.
Honing cylinders adds the cross hatching after boring, so that new rings bed in well.

 

[anyweb]

yeah i'll ask him to advise me on what to do, but first I need to hear whether the engine is usable or not, and i'm waiting for him to remove the sump and free the piston, only then will I know..

assuming it is usable, and if i didn't get it honed, but just cleaned it up, what would the net effect be, loss of power or ?

 

[Ken_R]

assuming it is usable, and if i didn't get it honed, but just cleaned it up, what would the net effect be, loss of power or ?

Unless it has previously been re-bored (to its limit) than it will certainly be useable. - Removable liners excluded. As regards 'honing', see Wikipedia,
https://en.wikipedia.org/wiki/Honing_(metalworking)

It's not something that I would consider on an engine of that age. If you found that you needed replacement piston rings then there might be some advantage by de-glazing the bores but, I'd be inclined to do that with just Emery cloth.

It's not as though we are dealing with anything high-tech here. It's just an old engine that needs a bit of TLC.

Perhaps I am a bit 'old School', but we managed pretty well before all these additional processes came into being.

 

[anyweb]

well today i'm gutted, the guy who's working on the engine called me, said now the stuck piston is loose but all 4 pistons have bad piston rings, and no compression, his advice get another working engine, as it would cost too much to fix this one

i'm in a bind, i don't know what to do, sell the car as is and hope i don't loose too much of what i've already paid, i still have to pay the mechanic for the bad news..

or, tell him to fix the engine and get 4 new pistons+piston rings...

or send the engine off to some place to get overhauled,

both of the last options will cost me an arm and a leg, but i'm in so deep now i don't know what to do, other than get a bank loan

this is so depressing.

 

[om613]

I think I'd enter into a dialogue with the vendor. Nothing ventured nothing gained..

It's been a long time. Maybe they forgot some important historic details here..?
As I see it, it had a head off 'rebuild' years back. That didn't work, as it needed a 'full' engine, which costs loads, so hence was stored.

 

[anyweb]

that's impossible as the guy is dead, so i cannot ask him... and his relatives claim they don't know the whole story,

so, if i was to get the pistons removed, replaced and piston rings replaced, is that a huge job ?

 

[om613]

This may be your best bet:
https://www.ebay.co.uk/itm/Mercedes...863868?hash=item5b4652edbc:g:UaAAAOSwn-tZKSWz

Being marinised and made upto 1990, they're well served it seems!

https://www.boatsandoutboards.co.uk/inboard-diesel-for-sale/mercedes-om-636/194701


Here a low mileage one for sale, from a car...:
https://www.ebay-kleinanzeigen.de/s...000km-aus-w120-ponton-180d/781981664-223-2733

 

[davemercedes]

Way, way back in the 60/70's I used to buy engine parts, particularly piston sets - (mainly for Perkins engines) from Ferraris Piston Service in North London. They still exist... they were always incredible helpful; might be worth an email?

https://fpsdistribution.com/

 

[anyweb]

This may be your best bet:
https://www.ebay.co.uk/itm/Mercedes...863868?hash=item5b4652edbc:g:UaAAAOSwn-tZKSWz

Being marinised and made upto 1990, they're well served it seems!

https://www.boatsandoutboards.co.uk/inboard-diesel-for-sale/mercedes-om-636/194701


Here a low mileage one for sale, from a car...:
https://www.ebay-kleinanzeigen.de/s...000km-aus-w120-ponton-180d/781981664-223-2733

thanks OM613, excellent resources, i'll have a think about all of them

 

[anyweb]

Way, way back in the 60/70's I used to buy engine parts, particularly piston sets - (mainly for Perkins engines) from Ferraris Piston Service in North London. They still exist... they were always incredible helpful; might be worth an email?

https://fpsdistribution.com/

thanks DAVE

 

[om613]

thanks OM613, excellent resources, i'll have a think about all of them

To answer your query, the bores are shot, so new pistons and rings alone are not feasible. Block needs reboring, that means a full strip down and rebuilding by a diesel specialist, who'll then check crankshaft, oil pump etc. A good one won't entertain doing 'half a job'.

Crewe engines have a good rep, I think even a common old OM like a 616 / 617 would be pushing £4K for a proper job.
http://www.creweengines.co.uk/remanufacturing_engines_process.htm
Your man was right...

 

[anyweb]

ok thanks, problem is, that engine that's for sale on ebay, could also be dead, this is turning out to be a nightmare