Camshaft ramblings 5.0 project - PeachParts Mercedes-Benz Forum

Tony H · #1 08-30-2012, 04:35 PM

I have been contemplating what camshafts to use in my 5.0 engine project. I wanted to use a cam close to the 3.5 profile since it seems to be more performance oriented than most other choices. 3.5 cams that are not worn out are difficult to come by and I want a repeatable formula. Looking at the list of cams in the factory manual the only other cam that is similar to the 3.5 are the 58/59 cams from a 420SEL. The 3.5 46/47 cams are:

intake opens 4deg ATDC closes 14deg ABDC
exhaust opens 30 BBDC closes 16 BTDC

The 58/59 cams are :

intake opens 4deg ATDC closes 14deg ABDC
exhaust opens 26.5 BBDC closes 11.5 BTDC

so the duration is the same with slightly less overlap. Plus the 58/59 cams are hydraulic so no adjusting valves and slightly more duration since there is no valve clearance. And 420SEL's that won’t pass smog are frequently in the Pick and Pull's so finding the complete valve train would be easy. Any thoughts?

bwostosh · #2 08-30-2012, 06:01 PM

Call the cam specialist at
Schneider Cams on San Diego,
known them since the 60's they may be of help.

They do my MBZ cams

Frank Reiner · #3 08-30-2012, 06:12 PM

I think that from time to time the cam specs we see must come from a variety of sources.

My MB manuals give the following: (all timing @ 2mm valve lift)

46/47 In. open 8, close 20. Ex. open 21, close 7
52/53 " " 4, " 14. " " 30, " 16
58/59 " " 4, " 14, " " 26.5, " 11.5
08/09 " " 22, " 21, " " 10, " 15

With the exception of 08/09, these cams are all listed for 116/117.98x engines, hence iron block 3.5/4.5. Also I believe that all the cams in the 40, 50, 60, and 70 series are mechanically adjusted.

The cams in the 00 series are hydraulic it seems (00/01, 02/03, 04/05, etc., including 18/19). The 420 (116.965) used 08/09 cams.

There are quite a few more cams than those cited above.

The longest duration hydraulic cams are 02/03 (192@2mm, in. & ex.) with 106 lobe centers. Other hyd. cams have 107 and 112 lobe centers.

The longest mech. cams are 54/55, & 56/57 (196 in., 200 ex.) 104 lobe centers.

The closer lobe centers of the mech. cams favor mid-range torque at the expense of fuel consumption.

Tomguy · #4 08-30-2012, 07:49 PM

Tony:

Keep an eye out for 3.5 cams if you really want them. You can find them it just takes time. What heads will you use? Keep in mind that you'll need 75+ heads with oil passages for the project. Still haven't heard officially, but MB documentation says the aluminum heads will NOT go on the CI blocks, so you'll need 75+ 3.5 or 4.5 heads. If you've already settled on pre-75 heads, they don't have the oil passages for hydraulic studs, so you'll need a matching mechanical cam.

Tony H · #5 08-31-2012, 02:13 PM

Thanks for the comments. I got the specs (2mm lift) out of my STAR Classic workshop manual that I bought from the Classic Center. Sounds like there are some variances depending on where the information came from-maybe offset keys were used on some of the specs. I plan on using K-jet 4.5 heads with the appropriate towers for the cams so I can use manual or hydraulic cams. The manual gives specific information on which towers need to be used on a particular cam(grooved or not grooved)
I guess the only way to know for sure is to install the cams and degree them.

My manual shows the 54/55 56/57 cams used in D-jet 450 cars as:

intake opens 5deg ATDC closes 21deg ABDC
exhaust opens 25 BBDC closes 5 BTDC

Cam lift or wear is not discussed in the manual so how would one determine if the cams are worn other than obvious physical damage?

Frank Reiner · #6 08-31-2012, 03:16 PM

Tony H.:

I agree on the timing specs for 54/55, 56/57, and that they are D-jet. My manual shows the application to be 117.982/983. Because there are two code groups with the same opening and closing points I have thought that there might be some differences in profile and (possibly) lift. For emission reasons, the 560 has been fitted with cams with lobe centers of 112 deg., hence, very little overlap. The industry trend has been to lobe centers of as much as 116 deg., but with increased mechanical compression ratio (up to 11:1) to regain compression pressure with a late closing intake.

As to wear, it is usually quite obvious when the hardening depth has been broached; the surface is no longer smooth, and the mating surface of the cam follower is usually gouged also.

Tony H · #7 08-31-2012, 06:02 PM

Thanks Frank. I have seen cams go flat and it usually does not take long once it starts. I'm trying to select cams from high production models usually found in the Pick and Pulls so I or others can duplicate my combination if it works out. There are always early and late 450's there as well as lots of 126 V8 models.

Frank Reiner · #8 08-31-2012, 08:42 PM

Of the mechanically adjusted cams, it seems that the US spec cars were fitted with 48/49, 52/53, and possibly 54/55, 56/57.

In the hydraulics, 00/01 was used in the iron blocks (117.985/986), and 62/63, 68/69, 70/71, 08/09, and 18/19 in the aluminum blocks. 62/63, and 68/69 need not be considered; they were used in the 3.8 in a desperate attempt to clean up emissions, and have very short timing.

It looks like I must retract my previous view that 60 and 70 series cams were mechanical. They were used in the alum. block engines, hence, probably are hydraulic.

Tony H · #9 10-01-2012, 11:41 PM

Has anyone ever measured and compared the lift of different camshafts? It would seem as displacement increases so should the lift. So 3.5 camshafts may not have as much lift as 4.5 cams. I have several different cams I am going to measure this weekend to see.

GGR · #10 10-02-2012, 11:32 AM

I did compare the lift of 3.5 camshafts with stock euro 5.0 and AMG 5.0 ones and the lift was less, though I don't remember by how much, but it was quite noticeable. So duration is not the only thing to be considered. Lift indeed increses with displacement, and 3.5 camshafts on a 5.0 may not yield the best results.

Tony H · #11 10-03-2012, 12:51 PM

I checked out the cams last night and it was as I suspected-the 450 cams have more lift that the 3.5 cams. Here are my results:

450 cam I .284”at cam .426” at valve cam 56/57
450 cam E .276”at cam .414” at valve

3.5 cam I .258”at cam .387” at valve cam 46/47
3.5 cam E .247”at cam .370” at valve

I think the 56/57 cams are ideal for my project. They are solid lifter cams so I can use them on whatever heads I wish and they are easy to find. I have seen the results of not changing oil on most of the cars I looked at for cams as the cams were gouged and worn from the oil tubes being plugged up.