The 380 head will not fit as aluminum engine heads don't fit on iron block engines. I think mixing heads could be probematic. I see 4.5 heads frequently on Ebay, etc. I think your repair would be much simpler if you can find the correct head.

Well, I not only need a 4.5 head, but a D-jet 4.5 head, which *I think* only came in the 108/109s. There is a 1972 SL engine for sale and it's hard to tell, but I think it's K-jet.
But you are right, it might be a lot easier to just find a head. Actually the piece that broke is pretty small, my machine shop could possibly weld it back... that part just goes around the timing chain, it's not 'structural'. I wonder if they can weld it without warping the head...

Csaba
72 280SEL 4.5

Welding might be an option. heads are welded to reshape combustion chambers and ports all the time. If you want to go that route I guess it's time to tear down the damaged engine to inspect for other damage. The '72 SL should be a D-jet-you can tell right away from the intake manifold.

A 72 US 350SL/450SL is pretty much the same engine. I'm going to be dismantling a 75 450SEL pretty soon which is also D-jet. Hit me up in a few weeks if you can't find one.

Hi Al,

I almost have the damaged head off, I just have to undo the downpipe. Boy, those allen bolts under the downpipe were a pain to get to, I ended up cutting the head off a long allen wrench, inserted it in the bolt and put a socket on it.
A friend reminded me that there are a few early 107s in area junkyards, so that's a workable route, except that I may not be able to get under a car in a junkyard to undo the downpipe from the exhaust manifold.

How much would you want for a head?
Thanks,

Csaba

It depends on how much of a pain in the rear it is to take off :)

Talk to me in a couple of weeks, I'm not sure when I'm going to be ready to part it.

If you need to get under a car in a junk yard, talk to the guys at the counter and they'll usually send a tractor out there to lift it up and put it somewhere where you can get under it. Good luck.

Well, I likely wouldn't be able to go to a salvage yard for 2 weeks anyways, as next weekend I'm busy.
Your '75 450SE - is that a Euro market or US car? I've seen one on CL for a while. BTW, if it makes it cheaper, I can pull it :-)
Oh, and I have '117' K-jet parts to trade from my spare engine. Heck, I have the spare K-jet heads to trade if you want...

It's this car: 1975 Mercedes-Benz 450 SEL beautiful dependable daily driver *Cheap!*

It's a US 450SEL that was "Euro'd" about 12 years ago. From what I understand, the top and bottom end of the engine was rebuilt then.

It belonged to a friend of mine who bought it of an MB enthusiast in NC about 4 years ago who did a lot of the work.

He sold it to a friend, who gave it to his son and it was eventually sold to another guy about 8 months ago, that guy managed to ruin it at an alarming pace.

I bought it as a parts car for a 6.9 that I'm working on. My goal is to get what I need out of it and sell the rest in order to recover some cost.

Also (not to step on Al's toes)
I have a 4.5 head in the basement @ my mom's house.

I DO NOT know if it's the left or right side. It may need valve guides, it def needs seals. It came of my 4.5 and it ran fine with that head on - I just swapped on the 3.5 D-Jet heads for better compression.

I may also have a cam or two (or 4). I'd need to check.

You're not, I'm a few weeks away for getting to it and the OP seems to need it right now.

Hi Al,

Yes, that's the ad I remember seeing. If it was a real Euro spec motor I'd be tempted to buy the whole thing, but if it's a US spec then it's no better than what I have.

Tom, if you could check which head you have next time you are there, I'd appreciate it. I took the left head off today and I'll take it to the machine shop tomorrow, but I am afraid it won't be repairable.

Here are some pics. The head was off before, as it looks like a newer type gasket on there, plus there is one of those round discs on it that machine shops put on rebuilt heads.
In the valley of the V the piece broken off the head is visible. Only the front exhaust valve appears to be bent, which is lucky (you can see its mark on the front piston). At least one valve is also bent on the right head, as there is a lot of valve lash on the rear exhaust.

BTW: 1. How are the cylinders numbered?
2. What color was the block originally?

Thanks,

Csaba