220S M180 Engine Work

[wbain5280]

I finally have the engine mounted properly and pulled the cyl. head. The rear head bolts were not tight, unlike the front head bolts which were. This engine had been replaced with one off e-bay because of a blown head gasket. The problem was not the head gasket but the undertight head bolts. I saw some deposits on the piston top and there is a problem with the head.

Piston 6:




Piston Walls Cyl 6





Cyl 6 Valves... check this out...

'

I'll have to get the head welded.

[Chas H]

That's some serious cylinder wall scoring. I'm not sure the block will be good once you get the head and gasket issues resolved. Fixing that head is gonna be expensive too.

[wbain5280]

The head should't be expensive, at least in my situation. I'm in automotive classes and there is a welding section in the same building. I can get one of the students to wend in some aluminum. As for the block, I think it's just aluminum residue on the walls, but the complete teardown will determine that. I do have a 230/8 engine in the car right now, with a knock and low oil pressure. I may have to use that one. it depends.

[Chas H]

The welding on the head cannot be done with the valve seat in place. Or if it is left in place it will likely fall out.

[t walgamuth]

I have one of those heads, I think.

If you are interested I will check for details.

Tom W

[cth350]

if you're going to look for a replacement head, start by posting the casting number. -CTH

[300SDog]

Originally Posted by t walgamuth

I have one of those heads, I think.

If you are interested I will check for details.

Tom W

Good offer, I agree with scrapping the original head. Has anybody actually done successful combustion chamber welding on alloy/aluminum cyl head? Nevermind if its warped or not. Massive problem in olden days was nobody knew how to plane cyl head surface without removing too much metal. Exceeding cyl head tolerances pushed compression through the roof and next goes wristpins and bottom end bearings.

And I was told these engine cannot be resleeved on account of tapered bores mated through intense heat/weld process to original thick high nickel content "sleeves" that more closely resembled cores. It aint like yer gonna be able to knock out the originals with a hammer. Probly gently hone/resurface scored surfaces instead. Then use original pistons and soft metal replacement rings. Piston slap is unheard of among m180's. And hieroglyph markings on each piston refer to weight and size, exactly ballanced to match the crank. Dont let any of the parts get mixed up.

I think less is better than more when it comes to working on m180 sortblock. If it was me: I'd gently hone existing bores, install new rings, get 2nd hand cylinder head, valve job guides and seals - thats all.

[Chas H]

I've had cylinder heads welded with good succes. And I've had engine blocks re-bored for oversize pistons-haven't heard of gas engines with original sleeves.

[300SDog]

Chas, then what you're saying is you've overbored the original nickel "core" to fit oversize pistons. Sounds kosher and oughta stand up 100k miles at least. For all intents and purposes these are sleeveless blocks as i understand em. Also nickel glaze surfaced at the factory diamond honed. Not exactly the kinda process that can be duplicated. Most folks just bought new MB factory shortblock when the old one wore out at 285k miles or so. Could be wrong, but welding aluminum alloy at combustion chamber alongside valve seat aint something I'd expect to find success with. Would be different if was hairline crack, say between coolant/oil passages not in the combustion chamber.

[Chas H]

Welding next to a valve seat requires removing the seat before welding and fitting an oversize seat after the welding is complete. In many cases it is more cost effective to fit a used head rather than to make a repair of this nature.
The Mercedes repair manual makes no mention of "diamond honing". A good machine shop will use the correct grit stone and crosshatch pattern to finish hone the bore.

[wbain5280]

Originally Posted by cth350

if you're going to look for a replacement head, start by posting the casting number. -CTH

OK, part number 180 016 22 01

I hope that's the right one, the only one I found, on the spark plug side in the middle.

[t walgamuth]

If you do a search in the parts forum for 220s head you will find mine complete with parts number.

Tom W

[wbain5280]

Tom

Yours is 180 018 26 01, so there may be substantial differences.

Thanks anyway.

[bwostosh]

Warren, those pictures lead me to a consider the need to
bore and re-new cylinder walls to new pistons. You should be able with the class equipment to do it easily.
Brian O. .

[t walgamuth]

Originally Posted by wbain5280

Tom

Yours is 180 018 26 01, so there may be substantial differences.

Thanks anyway.

Does anybody know the differences in the heads? and if they are interchangilbe?

Tom W