MSefi.com read only forum (Jan.15,2018)

Hi all,

Today I finished fitting the EDIS ignition set-up on my M117 5.0L V8 Mercedes engine. I cranked it with PIP/SAW unplugged to see if default advance was well set on 10°. After I pushed whatever adjustment I have on the VR bracket I'm still showing only 4° advance, so I'm off by 6°. I would need to make a new bracket to be spot on 10°. Is 6° something the trigger offset wizzard can take care of? I read somewhere there is only so much it can correct, but I can't find the info anymore. Is 6° within the range of possible correction for a V8?

Thanks in advance!

Yo.
Have some good news for you.
The 10 BTDC limp home mode is requiring a certain idle speed, which is higher than your cranking speed.
I have benchtested EDIS 4, 6 and 8 as standalone and when starting fron VERY low rpms ( 10) the ignition point
is 0 BTDC and at around 450 it has reached 10 BTDC where it stays rock steady up to 6800.
It is most likely a feature to assist easy starts at low cranking speeds.
So set the sensor exactly as it should be and I am pretty sure that when the engine starts to idle , no SAW connected,
you will get a steady 10BTDC.

Heribert

Indeed those are good news! I had taken great care of positioning the VR sensor when I made the bracket so I could not understand why I was off by so much. Though I hope the relation you mention is not a linear one because my cranking speed being a good 300 rpm (healthy battery) I should be around 7° instad of 4° advance. No need to panic at this point, I think the next step is to have the engine started (still some way to go).

BTW, I know you are familiar with these M117 engines. Would you know where I can find the stock ignition curves characteristics so that I can dial them in the system? This is a M117.960, out of a '78 450 SLC 5.0. It's a very early engine n°40, I guess the specs may not be too far away from the 4.5 ones. The only specs I have access to are for the 3.5 but I would imagine they would be too agressive for the 5.0.

Thanks!

Hi
QBTW, I know you are familiar with these M117 engines.UQ. It has been a very long time since I worked on a 450 SLC 5.0. I seem to rememer that advance at 3500 rpm without vacuum is 32 BTDC with another about 8 degrees with vacuum. Idling is 12 BTDC, but my figures are not at all certain! It is a marvelous engine. Take care and do not overadvance it!! And the 4,5 and 5,0 are very much different engines!
If you PM me I can give you a contact name at the MB Classic Centre in Stuttgart, they will give you the advance curve . Or if you are close to a friendly MB workshop, get to take a look in the workshop manual section 00, 01 ( Allgemeine data, technische data ) The advance curves will be shown there.

Take good car of the engine, I suppose you know that MB won the Bandama Rally in The Ivory Coast with engine like these.!

Best regards

Take good car of the engine, I suppose you know that MB won the Bandama Rally in The Ivory Coast with engine like these.!

I know! Unfortunately the car (No 52) was rusted beyond repair: my leg went through the footwell panel when I stretched to relax while driving on the highway! When I took it apart I also realised all the chassis rails were half gone. I got the engine, modified and reinforced a G76/27 5 speed transmission that I mated to the engine with a 3.5 flywheel, clutch and bellhousing and the whole thing will go in a '62 W111 Coupe.

I got some info about the ignition values on these engines:

Without vacuum:
cranking speed: 10 deg BTDC
1500 rpm: 14-22 deg BTDC
3000 rpm: 30 deg

With vacuum:
idling speed: +/- 3 deg (vacuum retard by 8 - 12 deg)
3000 rpm: 38 - 42 deg (vacuum advance 8 - 12 deg)

Are these values enough to set EDIS in the system? I do not have the centrifugal adjustment curve graph but I have the one of the 3.5 and above values are similar. The 3.5 graph stays at 0 deg up to 1000 rpm, then increases in a linear manner up to 28 deg at 2500 rpm and remains there as a plateau for all higher rpm. What I don't understand is that the graph does not correspond the the 3.5 values without vacuum: 10 deg at cranking speed (0 on the graph), 15 - 19 deg at 1500 rpm (19 deg on the graph) 30 deg at 3000 rpm (28 on the graph)...

Hi.
Sorry to go MB ranting but:
The W111 chassis , or any low pivot point swing rear axle MB, is not a suitable recipient of a potent engine like that. The 6,3 had of course lots of power , but as the saying goes in Germany " About half the indents in the railings along the Autobahn are made by 300 SEL 6,3s trying to brake from high speed."

I belive the factory shoehorned a 6,3 int a W113 , but that was along with a multilink rear suspension, so it can be done.

For advance curves I very much recommend factory figures. Please PM me your email adress and I will send the contact at the classic centre to you.

Best regards

Heribert

" About half the indents in the railings along the Autobahn are made by 300 SEL 6,3s trying to brake from high speed."

First time I hear that! I had a nice 6.3 some time ago and I never felt insecure, though I had a scary experience once in a W112 Coupe when I had to lift the gas pedal in the middle of a curve...

I'm sending you my email address via pm. Thanks!