Ive got the diesel crank , i found it on ebay , finally found complete c 36 motor so dont need the crankshaft

The 2 row timing chain on a M104 needs more space at the front of oil pan than a M103.

It can be done. When I built my turbo 103 I frankensteined a larger capacity oil pump into the motor. Ended up welding the gear on the pump as the bolt head caused interference with the 4-M sump.

A 648 in a 107. Lookout Mach4.

I can do a plug and play setup for you if you want.
Did you get my email about the gauge driver for your speedo by the way?

I am not sure what Mach4 means.

Yes I got it. I will probably take you up on that when I get off my butt. Lott of irons in the fire right now.

Mach4 is a guy who put a diesel into a 380SL. I believe his build thread is here but he may have another username.

I am wondering if you are speaking from experience on this? I double checked the pan gaskets and they seem to be the same. Mercedes has a different part number but the aftermarket lists them as all the same.. I know I checked all this out years ago with actual parts because I wanted to make a 104 4matic. I have been thinking about an om648 4matic w124 recently.
Just curious if I am missing something here that someone actually ran into as I never actually tried to build a complete setup.
They also made om603 4matics in Europe.

I know this from research / cut away pics rather than hands on parts. Somewhere on this site there were cutaways of the M103 and M104 + pan pics. I've searched but can't find it. The only real difference on the M104 was the pan front was moved forward something like 6 mm to clear the stack up of a dual row timing chain + oil chain.

The latest version of the pan gasket would work with a m103 as the difference was still within the outside dimensions of the timing cover.

If you have access to a pre M104 part number for a M103 gasket, it should be different. Is there a way to work backwards to superseded numbers?

So you are saying that not the bolt pattern but inside the gasket area the pan will hit. So some clearance issues. Anyways. The engine will still bolt in using stock engine mounts.

Depends on the pan, and as you know there are a bunch of different sump designs depending on the chassis. The 4-M pan is trickier than most but I'd bet its do-able. It bears mentioning that it has a handful of bolts that come in from the top that requires drilling the threaded holes in the block oversize. I've converted a non 4-m 103 block over before and it was not a big deal, the only deal breaker would be if the pan rail from the new engine is designed such that the few bolts that need to come from the top couldn't. Even then leaving a few out of a cast iron pan wouldn't be the end of the world.

Building my turbo motor, I was ready to glue my pan down when I realized that I had a bit of pump / pan interference. I was able to resolve it before the sealer set up. Of course it would be advisable to dry fit everything once to check and resolve any issues without being under the (glue) gun.

I'd like to contribute to this already informative thread to the members that build high performance and turbo M104's. I'd recommend sourcing an oil filter housing from a .980 or late model C36 '96-'97(my '95 C36 didn't have this). These units feature an oil cooler/heat exchanger. Don't forget about the corresponding water pump or check your existing one for the outlet on the back. I believe most of the 104's water pumps have that and it's blocked off by a removable plate.
I also agree with the previous post about the tricky oil pan that is reinforced and designed with a bunch of little fins to keep the oil from splashing around on the bottom of the pan and help direct it towards the oil pick up. It will help with oil starvation in those long high speed turns. I will try to post a picture and part#.


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Yes, bolt pattern same M103 / M104 but front wall moved forward a bit.

It is probably possible to mod a 4 M pan by extending the front a bit.

Hi,

I'm new to the forum. I'm in here mainly because I want to get good real-life info about Mercedes M104 engines and its variates. I have played the idea what would be the IDEAL M104 for the turbocharged street car that would use as many OEM parts as possible. Would it be 3.0, 3.1 3.2, 3,4 etc liter, based on 3.0l block or 3,2. What crank and rod ratio etc?.

I went through this thread but could not find proof if the then newer M104 head can be bolted to 300-24 block? So you could benefit from variable cam timing from newer head?

I have thought of building something with good low-end torque and sensible revs and with good rod ratio.


How about building something like this:

M104 block 88,5mm bore (more meat on cylinder walls)
M104 crank 84mm stroke (from 3,2 motor)
M104 88,5mm pistons (stock)

Some aftermarket rods 141 mm (to get the rod ration to 1,68 and compensate extra stroke). As comment all Audi turbocharged cars, RB26 or 2JZ the rod ratio is 1,65-1,67.

M104 newer version head with Variable cam timing. (there are aftermarket cams available via CatCams 268°/257° - 230°/220° - 10.45mm/10.15mm - 1.55mm/1.00mm.

With the newer head, I bolt on the stock intake manifold, fuel rail.

The engine would end up being 3,1 litre + variable cam timing from the newer head, better rod ratio. Would that work?

Maybe changing the crank from 80,25mm stroke to 84mm isn't worth doing for displacement sake but, if rod ratio is higher than say, 1.8, piston approach speed to TDC gets very progressive, and ignition timing threshold from a knock to not making power gets very very short. So I would do it making more power ;). If my calculations are correct then on 3.0-24v motor rod ratio is 1,81, in newer 3.2L engine ratio is 1,73. In 2.8L engine its 2.01

For the questions you are asking, have a look at the engine forum on speedtalk.com , there are some really serious engine builders there. Look through the old posts as this has no doubt been covered with other engines.

FWIW, all of the 104 engines have the variable camshaft timing.