117 (4.5) cam interchangeability

[vandor]

I have a broken left cam that was caused by a broken timing chain. The engine is a 4.5 from a '72 280SEL.
I heard that my engine uses solid 'lifters' (lash adjustment), whereas shortly thereafter the 4.5 went to hydraulic adjustment. Is this so, and are the cams the same? I ask because I have a complete '76 donor engine. If noone knows than I can measure both cams' profile with a dial indicator.

I know that as the years went on these engines were stangled with emission controls, so I wonder if a later cam would be different because of that.
Out of curiosity, will cams from an aluminum block engine work? Which engined had the hottest stock cam?
Thanks,

Csaba

[Tomguy]

The hottest 4.5 cams IIRC were the 52/53 series. Hydraulic cams are different than mechanical ones, and not interchangeable. I am fairly sure I still have a set or three @ my mom's house with that spare head, just haven't had a chance to actually look at all lately.

Because hydraulic & mechanical cams aren't interchangeable by default aluminum block cams won't work... on your older engine. They could, in theory, work on the newer one. However don't QUOTE me on that due to the slightly different head bolt pattern, and the fact that the cam towers have a bolt that's also a head bolt.

[vandor]

>The hottest 4.5 cams IIRC were the 52/53 series

And were those mechanical or hydraulic?

Thanks,

Csaba

[Tomguy]

Mechanical. I think that the hydraulic 4.5's all had the same cams?

[Tony H]

What is the number stamped on the rear end of the camshaft? (52/53, 54/55, 56/57 etc?)
There are several different mechanical cams used in the 116 and 117 engines. I copied the cam chart from the manual but it is too big to post here. If you PM me I will email it to you.

[vandor]

I just checked, and they are 52 and 53. However the left cam is buggered ('52' I think), the end is a bit messed up and the bolt is broken into it.
It may be easier to get another, but I'd have to get the rocker arms with it too.