1982 500SL new reco engine
 

Hi folks , I am needing a little help on MB engine numbers from the early eighties .

I have a 500SL 1982 Euro and need a new engine due to excessive oil use after high milage on this car over many years .

I have been offerred a fully reconitioned 500 block with engine no M117 961 xxxxxxxx,out of a 1984 500SEC or SEl (not SL ).

Can anyone provide some info on this engine , is it Euro or US spec would it have the same horse power as my old SL engine ( M117 960 ).

I will be using all the top end of my old engine including manifolds and fuel systems etc, and just the 500 reco Block M117 961. What will the resulting horse power be from this mix of engines .

Appreciate your comments

Den Downunder .

The 1984 500SEL/SEC USA engines were 117.963 versions at 8/1 compression.

USA never received the 117.961 version!

M.B.DOC,

Many thanks for your advice, however I would appreciate a little extra information and opinion if possible.

Regarding the 1984 M117963 engine with 8 to 1 compression , what would be your view regarding horsepower output if we built a new engine as follows-

A. Use the M117963 Block fully rebored with next size pistons.

B. Use the heads and all other components including manifolds etc and no catalitic converters from my 1982 500SL M117960 engine .

Would the engine still have 240 HP as the original M117960 500SL Euro engine.

Again , your views greatly appreciated.

Den Downunder.

( Needing new engine )

i would say yes
 

the difference i believe is only in the high compression pistons in the block. the cams are diff too and perhaps some subtle differences in the fuel injection system to feed a hungrier engine.

i have a 500sec and it is pretty satisfying to drive.

i ahve driven a euro 500 sedan though and it was noticably quicker even being a bit heavier and with a 224 rear end instead of the 247.

if you have the part numbers my favorite machinist has a mahle distributorship and can get you the pistons, i believe. if you want his phone number pm me.

tom w

Tom Many Thanks for your comments it is appreciated.

Sorry but we have new pistons which are High Comp.

Any other comments appreciated while building engine to get more oomph.

Den Downunder

From the data I have both engines are the same power output. However there is a low compression version of both engines. The only difference between the 960 and the 961 is that the 961 was used in SE's SEL's and the 960 was used in SL's and SLC's. The only problem I see is if you replace a high compression version with a low compression version. This would not be likely if both engines came from the same country. The differences are most likely things like exhaust manifolds and airfilter housings etc.

117.960 177kw @ 4750 RPM 8.8:1 compression
117.960NV 165kw @ 4750 RPM 7.5:1 compression

117.961 177kw @ 4750 RPM 8.8:1 compression
117.961NV 165kw @ 4750 RPM 7.5:1 compression

Now you have the engine out and half appart. There was a 965 version available with 8:1, 9:1 and 10:1 compression. The 10:1 compression engine without a cat put out 195 kw at 5200 RPM. It probably also had a different set of cams. These parts might only be available in Germany??.

The data I have came from my 107 service CD

John Roncallo

i think
 

his engine is a euro, isnt it?

in 82 the 500 was not offered here, i dont think.

tom w

Many Thanks Guy's for your info ,.

To Further clarify my situation I would like to say -

A. My 1982 500SL according to the data in " the SL experience booK " indicates that the Euro 500SL produced 240 H.P.( DIN ) @ 4750 RPM .
this is a M117 960 engine with no cats, and is the fastest of all 1972 to 1989 SL's .

B. I will be using the 1984 Euro 500SEC block only M117 961 and all other components from my old Euro M117 960, to reco the motor .

This is a mix of two engines , there seems to be a consensis that there will be little difference in performance spec's .

Do you still hold that view ?.

Den Downunder .

sorry
 

but the facts are a little too subtle for me to follow.

the block the 961 you are subbing for a 960? both are euro 500 blocks? do you know the difference in them? i would suspet that the earlier 500 block might be a little more rugged being from the sl which was a pretty hipo engine.

this is just a guess.

i didnt know there were two blocks in that era. i would try to get more detailed info on the differences to be sure.

tom w