W108 '73 280SE 4.5 Timing Rail?

[Schnell]

I've been cruising CL (as usual) and I spotted this nice W108 for sale- I emailed the seller and asked what the motor issue was (having noticed that the valve cover was off) and he said that the "timing rail broke." After some quick searching and noticing that it's the right EDIT: Erm, stage right bank, I assume it's the timing chain tensioner. Any other ideas? Also, is this engine salvageable or would I have to source a new unit?

Thanks.

[GGR]

The cam cover is off on the left bank, and it is usually on that side that the rails brake. 109.000 seems a bit low for a rail to brake, may be the car has more miles than that.

Usually the rail gets sucked between the chain and the sprocket and jumps some teeth. This being an interference engine, the probability for the valves to end-up bending on the pistons is quite high. If the rockers have jumped out of place then it happened.

Even if you need to source another engine, if the rest of the car is nice, $600 is cheap. In last resort you will make more than that parting it out.

[Tomguy]

I agree that $600 is cheap for that. In fact, if I had a garage, I'd be tempted to drive down to TX with spare driver & pass head assemblies (incl cams & rockers), timing chain and rails, and drive it home. Mileage isn't why the rails break, it's usually age. The plastic isn't meant for long-term exposure to heat & oil. The original-style aluminum-backed rubber rails are far superior for any long-term solution.

If the car has as little rust as the pictures would seem to show, I'd hop on that in no time. I'm surprised Al hasn't bought it yet - although I guess it would need too little work!

[Schnell]

Thanks for the information. I'm still waiting on another response from the seller for more pictures. I wouldn't mind do an in shop rebuild either as to avoid shipping costs...Any good places to source parts? Either re-manufactured or new? I imagine that I'm looking at about $1,000 worth of parts if not more, so this would be a longer term resto.

[Tomguy]

Depends where you get them from & what you get. A set of 4.5 D-Jet heads out of a junkyard car, have a shop do the seats & valve stems & seals on both for peace of mind, shouldn't be more than $1k with the job (and probably $200 if you just get heads that "Look good" and pop them on).

[Schnell]

Really? I went on eBay quickly and found an M117 left-side head for $250 out of an R107. I know the M117 was in use for a while throughout the MB line (with D-Jet until '76), so am I able to use any head from any car? i.e. W116/R107

If so, I'm probably going to go crazy and empty my savings

[gear-head]

Hmmmm, yup, sounds like a purty good deal on a project to me! Definitly plan on pulling that head, maybe your favorite local machine shop could salvage it, rebuild it for you reasonably. It may not have all that high mileage, but those plastic chain guides will break just simply due to age. It's critical to replace those guide pieces as part of regular maintence for this very reason. I've been told so many times by so many life long career MB mechanics that it is not a matter of "If" they break, but rather "When" they break. These must be replaced periodically regardless of miles, age is just as big of an issue in not only these MB engines, but all MB engines that have them but especially gasoline V8 engines of whatever MB family. Just my two cents on what I've been taught and just passing it on for whatever it's worth. IF that car is as solid an clean as it seems, I'm just about glutton enough for the punishment that I'd jump on it too! If you need a good replacement cylinderHead, let me know, I bet I know a good source for one that is probably reasonable price.

[Schnell]

A friend found some heads on eBay, I don't believe they're missing anything (except gaskets). So it looks like I'm ready to go, outside of gaskets and the rails, hopefully nothing else needs attention.

Edit: I fear it may be sold by now, the seller deleted his post.