Retrofitting a 02-cam into US-spec M130 engine

[Berggreen]

Dear All

I am currently considering to retrofit a 02-cam (A 114 051 02 01) into my US-spec M130 engine in my 1970 280SL (manual).

The old 05-cam (A 114 051 05 01) currently installed in my engine is a bit worn, and I would also like to benefit from the better performance gained from a Euro-spec cam like the 02, when replacing the cam. In addition, all US-spec ignition parts have been removed or disconnected, and a 123ignition installed instead. I also found a Euro-spec throttle house, which I will install together with 02-cam to remove the last remains of the US-specs. 

I can get the 02-cam new from Mercedes here in Europe for 684 EUR, but I am unsure if the cam will at all match and fit into my current engine head in my engine. I have attached a picture of the casted head number in my engine, which is: 130 016 32 01.
Will a 02-cam fit into this head, and if not which parts do I have to replace to make it fit, if at all possible?

Furthermore, which additional parts should I buy with the cam?
I guess when I have the "patient" open anyway, I should replace additional parts like camshaft bearings, cam sprocket wheel, camshaft chain and tensioner, etc.. Or what do you think?
What would you recommend to change and do you have the Mercedes part numbers I should look up?

Thanks a lot in advance for your help! 

All best,

Christian

[cfm65@me.com]

Hi Christian,
I can’t advise you on the new cam, however.
I replaced the rockers as well as the little ‘shoes’ between the valves and the rockers. Also the timing chain while you are there.
Regards
Chris

[450sl]

Hi Chris,
There is a possibility that the Mb-Cam needs to be ground to meet your bearings specs.

You might want to consider sending your old cam to Kentcams to be upgraded to better performance specs.

Can recommend Kentcams they do an excellent job.

Mark

[Cees Klumper]

Conversely you can purchase a new set of cam bearings to fit the cam, if the current bearings are too small or too tight. Clearances should be in the 'Tabellenbuch' which I don't have handy

[Berggreen]

Thank you all for good input. :-)

However, it would be great, if someone would know or have experience with retrofitting an 02-cam into a US-spec engine head like mine. That would give me peace of mind, before investing in a new 02-cam from Mercedes and the associated parts. :-)

Thanks again,

Christian

[ja17]

It's not a problem. You just need to be aware that there are two different bearing journal diameters with various cam configuration in those days. The earlier cams used a smaller diameter than the later. You have to use the cam supports which have the correct internal diameter. I am not sure if your cams have the same diameter and can use the same cam supports. If you buy new, then the parts supplier will have to order the correct ones.

[MikeSimon]

Listen to Joe! I don't think the head is the issue. The number on the head will not tell you much, other than it is a later issue head. The key thing are the sizes of the journals. I have a 02 cam in my car and the head is currently off. I can measure the journal diameter, if you want to, and you can compare this with your support sizes. Let me know

[ja17]

The camshafts with the larger diameter journals use the cam supports with the "X" casting. Others with the smaller ID. do not have the "X" casting (see pic.).

[MikeSimon]

280SL Cylinder Heads and the lack of documentation thereof....my pet peeve...Nothing in the BBB for M130 engine.
Has anybody recognized that Bergreen's head is also missing the compression ratio marking above the casting number?

[Benz Dr.]

I wouldn't grind the cam bearing journals to match the cam bearings for any reason. Once you grind something it's gone forever. Not that anyone here would do that, right?

[Berggreen]

Listen to Joe! I don't think the head is the issue. The number on the head will not tell you much, other than it is a later issue head. The key thing are the sizes of the journals. I have a 02 cam in my car and the head is currently off. I can measure the journal diameter, if you want to, and you can compare this with your support sizes. Let me know

Thanx a lot to all of you for great input and help! :-)

Sounds like I should just start by buying the new 02-cam from Mercedes, while they still have it Im stock and then worry about the cam bearings once I have it all taken apart.

However, Mike it would be a great help if you can measure the bearings in your 02-cam so that I maybe can source the new bearings before taking everything apart. Highly appreciate it Mike. :-D

Cheers everyone! :-)

[jeffc280sl]

i have a 1970 US 280SL manual tranny.  I did this same project 10 years ago.  here is a link to my post

https://www.sl113.org/forums/index.php?topic=12289.msg83208#msg83208

[Berggreen]

By the way, on the side I also pushed my local MB dealer to look up some part numbers for both by existing 05-cam as well as the 02-cam I want to install.

They state that both the 05-cam (114 051 05 01) and the 02-cam (114 051 02 01) both matches this cam bearing repair-kit (114 586 04 05) as well this set of loose cam-bearings (114 586 05 05).

Does this make sense?

Also, do you know what parts a repair kit includes, and if I actually need it, or can just get away with changing the loose cam bearing alone?

I also found this overview online of the various casted head numbers. Mine seems to the one at the bottom of the list fitting a very late US 280SL.

Actually, the engine must have been changed or received a major overhaling because the engine number starts with 981, even though the rest og the engine number matches the datacard. My lokal MB dealer states that his system says based on the engine number and baumuster that the original 983 engine was born with a 05-cam.

So my theory is that in connection with the overhaul the head was reused from the original 983, whereas the block was replaced with a 981 block which they happened to have on the shelf, and then they just hammered in the 983-engine number from the datacard.

Does this make sense?

Cheers,

Christian

[Berggreen]

i have a 1970 US 280SL manual tranny.  I did this same project 10 years ago.  here is a link to my post

https://www.sl113.org/forums/index.php?topic=12289.msg83208#msg83208

Fantastic, thanx a lot!! 

By the way, if you also went from a 05 to a 02-cam (?), how much of a difference did you actually record in performance at different revs?

I would be very interested in hearing you experience before I start up the project.

Cheers,
Christian

[jeffc280sl]

You're welcome.  Change went smoothly as I recall.  Did not change any bearings

[Berggreen]

You're welcome.  Change went smoothly as I recall.  Did not change any bearings

Did you also go from a 05 to a 02-cam?

If so, how much of a difference in performance did you record at different revs?

I would be very interested in hearing your experiences, before I start up the project.

Cheers,
Christian

[jeffc280sl]

i went from a stock usa cam to the euro version.  i was tuning the fip around the same time so i cant say for sure i noticed a big performance improvement.  ive made quite a few changes over the years and im happy with what current performance

[MikeSimon]

My German spec late 280SL is rated at 170hp DIN with the 02 cam. I am not sure what the rating for the US market is. May not be a recognizable difference. Most of the different tuning stuff was done for emission reasons. The peak horsepower and torque may be the same just at a different rpm point.

[stickandrudderman]

BEWARE, Mercedes cam bearing sets don’t fit the new cam (bearing diameter too small).
Search the forum for more info.

[Berggreen]

BEWARE, Mercedes cam bearing sets don’t fit the new cam (bearing diameter too small).
Search the forum for more info.

Thanks for the warning!

Do you mean that a 02-cam (114 051 02 01) does not matches this cam bearing repair-kit (114 586 04 05) as well this set of loose cam-bearings (114 586 05 05), which my local MB dealer found as matches in his system?

Do you happen to have a link for the forum discussion you are referring to?

Thank you for your help! 

[ja17]

There has been some discussion that, these days, new cam bearing sets do not come sized and have to be machined to fit the camshaft diameter. I have not experienced this and cannot verify this is the case.

[MikeSimon]

If there were two different size cam supports, it is possible that Mercedes only supplies one size now for them to be machined to whatever size you need.

[Berggreen]

If there were two different size cam supports, it is possible that Mercedes only supplies one size now for them to be machined to whatever size you need.

I just thought that MB has chosen the size bearings to fit the later cams like 02 and 05s. Thus if you have an older 09-cam they will not fit. Or am I wrong?

Cheers,

Christian