High tech injection system for the 616, 617 - Page 2 - PeachParts Mercedes-Benz Forum

ARINUTS · #1 01-14-2008, 12:23 AM

It wouldn't really be a direct injection system as the prechamber would not be eliminated. thats the hard part and really not all that necessary.

jkoebel · #2 01-14-2008, 07:09 AM

I'd totally swap a 220 CDI engine into my 240D, with a new transmission...trouble is I don't know where to get one from.

t walgamuth · #3 01-14-2008, 08:01 AM

Well, now there are some possibilities!

The one system apparently is already being marketed, but at $7000 the payoff would be pretty long!

I am not sure a system like megasquirt, designed for gasoline, would work for the heavier viscosity diesel fuel.

Tom W

#4 01-14-2008, 08:17 AM

Megasquirt is a computer system, not an injection system.

Tymbrymi · #5 01-14-2008, 09:12 AM

Quote:

Originally Posted by t walgamuth

I am not sure a system like megasquirt, designed for gasoline, would work for the heavier viscosity diesel fuel.

As Forced said it is a computer not an injection system so there is no such thing as megasquirt injectors, etc. Still, megasquirt is designed for gas engines, which do not need precise timing on injection events. You just spray a bunch of gas into the intake (or in front of each valve if you want) and you're good to go. A diesel wouldn't run too well that way.

vstech · #6 01-14-2008, 09:36 AM

another obstacle is compression ratio on these cars. DI ratio's are around 14:1, where our IDI CR is around 22:1. so is this plan to just computerize the existing IDI injectors, or to upgrade to DI injection? cause I don't see computerizing IDI as much of an improvement. and I don't see DI working at 22:1 CR... so you are talking about not just redesigning the injectors, you are talking about redesigning the piston and head dome... um. not really possible, but if you think STOCK 616/617 pistons are pricey... try one off pistons...

t walgamuth · #7 01-14-2008, 09:47 AM

Well, this is good information.

Not what I was hoping to hear but good information.

I am interested in Gurkha weighing in with the Indian connection to advances relative to the 616 617.

Tom W

#8 01-14-2008, 10:34 AM

On the Mercedes side of things...

The OM 602.98x was Mercedes' direct injection version of the OM602.9x. Introduced in the 1996 E290, Sprinter and Unimog it used a rotary injection pump and an intercooler. Power was mostly the same.

Hatterasguy · #9 01-14-2008, 12:34 PM

Quote:

Originally Posted by ForcedInduction

On the Mercedes side of things...

The OM 602.98x was Mercedes' direct injection version of the OM602.9x. Introduced in the 1996 E290, Sprinter and Unimog it used a rotary injection pump and an intercooler. Power was mostly the same.

Looks like a less complicated swap. Good luck trying to get one in this country, you would have to import it.

vstech · #10 01-14-2008, 12:50 PM

Quote:

Originally Posted by ForcedInduction

On the Mercedes side of things...

The OM 602.98x was Mercedes' direct injection version of the OM602.9x. Introduced in the 1996 E290, Sprinter and Unimog it used a rotary injection pump and an intercooler. Power was mostly the same.

hmm, so power was unchanged in this powerplant, was efficiency improved?
if the CR is different only for added turbo boost, then it's the boost that gives the additional power, not the DI/IDI thing... so... if we put a thicker head gasket on our 617's added a bigger turbo for more boost, and enriched the fuel... would we get a big boost in power without the danger of high EGT? ... HMMMMM

#11 01-14-2008, 01:08 PM

Quote:

Originally Posted by vstech

if we put a thicker head gasket on our 617's added a bigger turbo for more boost, and enriched the fuel... would we get a big boost in power without the danger of high EGT?

No, you would have lower power and reduced efficiency because of the reduced squish area between the head and piston. If you want to lower the compression ratio you would have to machine out the bowl of the piston.

patbob · #12 01-14-2008, 01:09 PM

Converting to direct injection would involve a new head and pistons at a minimum.

However, convering the existing indirect system to common rail injection seems a lot less involved. Need feed pump, sensors, switchable injectors, computer controller and common rail (manifold).

Is this more what you had in mind Tom?

Also, any possibility the existing IP could be used as a feed pump -- disconnect throttle & ALDA and wedge in WOT? That would make playing around with the idea a lot less involved and potentially easily reversible, provided you din't blow up the engine

lupin..the..3rd · #13 01-14-2008, 12:10 PM

Quote:

Originally Posted by vstech

another obstacle is compression ratio on these cars. DI ratio's are around 14:1, where our IDI CR is around 22:1. so is this plan to just computerize the existing IDI injectors, or to upgrade to DI injection? cause I don't see computerizing IDI as much of an improvement. and I don't see DI working at 22:1 CR... so you are talking about not just redesigning the injectors, you are talking about redesigning the piston and head dome... um. not really possible, but if you think STOCK 616/617 pistons are pricey... try one off pistons...

Compression ratio has nothing to do with DI vs. IDI. Nothing. VW TDI motors are direct injection and they operate at 17.5 to 1. The C220 CDI operates at 18:1.

The reason for the slightly lower compression ratio is the increased turbo boost. The newer engines run much higher boost, hence the reason for slightly lower CR. For the same reason, a normally aspirated diesel motor will have a CR that is higher still.

Gurkha · #14 01-16-2008, 09:21 AM

Has been done, Force Motors India which is a MB partner here sold their G Wagen clone called Gurkha with OM616 turbo in Germany. With latest BOSCH pump, it passed stringent Euro-IV requirments.

t walgamuth · #15 01-16-2008, 10:28 AM

Is it feasible to transfer that technology to an old engine?

Tom