Worn cam "bearings" M110 - PeachParts Mercedes-Benz Forum

Mr_Goodkat · #1 03-29-2021, 04:52 AM

Hello.

Im in the process of restoring a M110 engine and have run in to a bit of trobble.
The Bearing surfaces in the cam housing is worn out and the bearing surface on the camshafts dont look too happy. The diameter on the shafts is stil in spec but the surface finish is way of. And the cam housing itself is no where near the right diameters. Now, referring to the worksohop manuall you shoud grind down the camshafts and fit a "repair stage" cam housing. Unfortunally repair stages cam housings have not been avaliable for around 20 years.

But! This gave me an idea! If I can find a machine shop whit a line boring machine they can bore out the old bearing sufaces put in new "busching" and line bore those to a suitable dimension and then grind the camshaft to fit the new bearing dimensions.

Have anyone done a repair like this? And if yes, did you have any success?

/Stefan

Sugar Bear · #2 03-29-2021, 08:37 AM

IMO that would work. Consider asking a Mercedes engine rebuilder e.g., Metric Motors? if they have a solution for this problem.

Good luck!!!

Mr_Goodkat · #3 03-29-2021, 04:47 PM

Well, could not get hold of the local old Mercedes shop to day but had a chatt whit my usuall engine rebulid guy. The problem is it is rather hard to get hold of anyone whit the right type of line borring machine, he did not know anyone that hade one. But after some brainstroming we came up whti an alternative solution.

One, we can spray weld the shafts to oversize, give the cam housing a light totch up whit a honing tool, and then regrind the shafts to fit.
Two, turn down the journal on the shafts and then sleeve them and machine the sleeves to size. And again give the cam housing a light totch up.

I think solution two is to prefer, I can use hard steel much more suitable for shafts than the soft steel used in the cam shafts, and I have acces to all the machines I need for the job.

cth350 · #4 03-31-2021, 11:37 PM

want a used cam box? drop me an email. -CTH

Benz Dr. · #5 04-01-2021, 09:26 AM

I would go the used cam box route. You might even want to go with the cams that with it.

Frank Reiner · #6 04-01-2021, 06:42 PM

Quote:

Originally Posted by Mr_Goodkat

But after some brainstroming we came up whti an alternative solution.
One, we can spray weld the shafts to oversize, give the cam housing a light totch up whit a honing tool, and then regrind the shafts to fit.

Quote:

Originally Posted by cth350

want a used cam box? drop me an email. -CTH

Quote:

Originally Posted by Benz Dr.

I would go the used cam box route. You might even want to go with the cams that with it.

Mr. G:

A used cam box with good, on-size bearing points is the preferred solution.
Spray welding alloys are available that are harder than the original camshaft journals, and will give a better bearing surface than the original.
You have probably noted that over time MB eliminated some of the journals; eight on the exhaust side were reduced to five, and seven on the intake side were reduced to five.

801mbz · #7 04-03-2021, 04:08 PM

I have several motors call me 801706 6871

Mr_Goodkat · #8 04-05-2021, 01:42 PM

Quote:

Originally Posted by Frank Reiner

Mr. G:

A used cam box with good, on-size bearing points is the preferred solution.
Spray welding alloys are available that are harder than the original camshaft journals, and will give a better bearing surface than the original.
You have probably noted that over time MB eliminated some of the journals; eight on the exhaust side were reduced to five, and seven on the intake side were reduced to five.

Of course a new or good used cam box whit cams and probably the chepest and best soution BUT! The cams are regrund dbilas cams, all the lobes are perfect and I dont want to throw away two 500 euro cams :/ And lets say I get a good cam housing. The wear surface on the cam journals are still bad. And to be honest, I do think it is a bit of fun to see if i can fix this problem using the old cams and housing. Yes, I noticed. The engine is from a very late W126 280SE and only have four jornals on each cam, well it has five on the exhaust cam but only use four. The fifth dont have any bearing surface to run agianst.