What M116 in the '86 420SEL? - PeachParts Mercedes-Benz Forum

Hit Man X · #1 08-19-2006, 03:05 AM

Does anyone know what M116 is in my '86 420? M116.964 or M116.965?

JimmyL · #2 08-19-2006, 03:07 AM

Quote:

Originally Posted by Hit Man X

Does anyone know what M116 is in my '86 420? M116.964 or M116.965?

I myself often wonder that at 2:00 in the morning.....

JamesDean · #3 08-19-2006, 03:11 AM

shouldnt u be able to tell from the identification plate? or vin number?

Hit Man X · #4 08-19-2006, 03:12 AM

I scoped the ID plate, 126.035... I figure it's the .965 aluminum block.

If so, means Euro 500 cams will bolt to my 420.

david s poole · #5 08-19-2006, 10:41 AM

hit man your engine is 116-965

Hit Man X · #6 08-19-2006, 12:07 PM

Excellent news!

JamesDean · #7 08-19-2006, 02:35 PM

fyi

if u put the vin # into the russian vin decoder it will tell you the engine

like my SD

VIN WDBCB20AXCB021778
Model 300 SD
Chassis 12612012021778
Engine 617951 12 021046
Transmission 722303 02 161756

ctaylor738 · #8 08-19-2006, 02:52 PM

Why don't you simply look at the engine serial number on the block?

Tomguy · #9 08-19-2006, 03:12 PM

Why would euro 500 cams not fit in it if it were a 116.964? I've heard of 4.5 cams being put into a 560 with just replacement of the hydraulic ball studs with mechanicals. And I know 3.5 cams work fine on a 4.5 - I've done it. I am pretyt sure they'd fit either way.

But wouldn't 420 cams already be more agressive than 500 ones, regardless of euro or not?

Hit Man X · #10 08-19-2006, 03:39 PM

Quote:

Originally Posted by ctaylor738

Why don't you simply look at the engine serial number on the block?

Maybe because I don't know where it's located...

Quote:

Originally Posted by Tomguy

Why would euro 500 cams not fit in it if it were a 116.964? I've heard of 4.5 cams being put into a 560 with just replacement of the hydraulic ball studs with mechanicals. And I know 3.5 cams work fine on a 4.5 - I've done it. I am pretyt sure they'd fit either way.

But wouldn't 420 cams already be more agressive than 500 ones, regardless of euro or not?

I figure since the Euro 500 is a larger motor with more power, the cams have to be larger than the US 420 ones... Now I figure US 420 cams are larger than US 500.

Documents I found show that all these motors will swap cams:
M116.964/965 und M117.961/963/964/965

Tomguy · #11 08-19-2006, 05:08 PM

There's a chance the cams are the same.

Also, because an engine is bigger doesn't mean it has "larger" cams - for example, duration of 3.5 cams is longer than those of a 4.5 (m116 vs m117). I would assume the same to be true of 500 vs 420 cams, since the 420 has less displacement, it has a longer duration to compensate for that.

Hit Man X · #12 08-19-2006, 05:29 PM

Quote:

Originally Posted by Tomguy

There's a chance the cams are the same.

Also, because an engine is bigger doesn't mean it has "larger" cams - for example, duration of 3.5 cams is longer than those of a 4.5 (m116 vs m117). I would assume the same to be true of 500 vs 420 cams, since the 420 has less displacement, it has a longer duration to compensate for that.

Hrm, I figured they were setup for that certain motor. I know where some Euro 380s ones are at too, if they're larger yet?

Is there anywhere I could find the duration (.050" and .006"), lift at valve, LSA, and the ICL?

Tomguy · #13 08-19-2006, 06:48 PM

The duration needs to be derived from the openings and closings which should be listed in the engine manual (m116/m117 service manual, I believe seperate ones were made for the 3.8/5.0 and then the 4.2/5.6). There is also at least one posting on this forum that lists the openings, closings, and durations for common 3.5/4.5 cams; your best bet for power in a 420 aside from stock cams would probably be 3.5 cams with matching mechanical studs.