Hmm, Thats pretty heavy duty work for a 616!

--Is it 'standard' below-decks!??

__________________
http://i190.photobucket.com/albums/z...0TDnoplate.jpg

Alastair AKA H.C.II South Wales, U.K. based member

W123, 1985 300TD Wagon, 256K,
-Most recent M.B. purchase, Cost-a-plenty, Gulps BioDiesel extravagantly, and I love it like an old dog.

W114, 1975 280E Custard Yellow,
-Great above decks needs chassis welding--Really will do it this year....

The engine is stock.

If there is anyone out there that has a diesel timing light and is bored, I am trying to find out what the Injection timing advance mechanism curve looks like on a 616 /617.

I see in the SM that there were a few different advance mechanisms with different amounts of advance, ( the 7 degree not recommended on engines with loop plugs), but no info on whether it comes in right after start up or gradually advances as RPMs increase.

With a timing light this should be easily seen. I am going back and forth in my head about injection timing and it would be nice to know what that thing is doing so I can narrow down my train of thought.

I also ordered three different part numbered MW elements, 1 418 415 051, 1 418 415 065, 1 418 415 118, to see what the differences are. I am looking to see if one has a leaner helix, if there is a difference in fill port size, and perhaps a stronger barrel. If I can find the one that is closest to what I want in the end, I will have less to modify.

The elements finely arrived today. I am surprised at how different they each are. The ones I ordered have the thick flange and will fit in a P Pump as well. I like the upper seal groove they have because I am going to be running very high lift pump pressure, but the barrel wall thickness above the fill port is thinner than the thin flanged barrel.

The fill port diameter and plunger helixes are very different as well. The output capabilities are very different

I was leaning toward the thicker flanges because of the 200 bar target pop pressure, but I do not like the thinner barrel wall where the high pressure will be generated.

I will spend more time evaluating each one before I decide on which one to use, but right now I would go with the thin flanged one.

Are you worried about metal fatigue/failure? Do you have anyone who can do a modal analysis / FEA?

__________________

Gone to the dark side

- Jeff

I have seen a MW speck sheet some where that, if I remember correctly, gave a max injection pressure of around 1000 bar. Also because the plunger area is small, the cam will only see a percentage of the injection pressure.

Additionally the strain on the cam is related to where the pressure is generated on the lift ramp. One of the barrels I ordered has a 2.5mm fill port diameter vrs the 3.5mm and 3.7mm diameters of the other barrels. I like that because less fuel is moved in and out of the barrel during port opening and closing. More small ports can be added to increase the flow capacity along with higher lift pump pressure.

I am additionally leaning toward the small fill port concept because it will allow me to close the fill port at a lower point in the lift ramp, this will give the cam more leverage and reduce the speed of the pressure rise. I am concerned that the 10mm plungers will deliver the fuel charge too quickly, and I am looking at the lower part of the cam to help slow the rate of injection down.

As for the injector lines, I am at a loss for a pressure rating. These engines were not designed to run 200 bar so the lines may present a week link in the chain.

Am I missing something?

After some thought, I am going to start testing the 1 418 415 065 element, it has the small fill port and is ideal for the shortened lift cam I am intending to use.

I will still have to grind the plunger helix to reduce the possible amount of fuel delivered at full rack travel to around 90 ish ccs per 1000 strokes.

I want to know two things, one, where in the plunger lift, after port closure, dose the pressure reach the targeted 200bar, and two, what the plunger angle, (simulated rack position), is with a delivery quantity at about idle.

Then I will increase the quantity of fuel to the targeted 90cc per thousand and see at what angle the plunger is, and compare the idle and full power plunger angles to determine the new angle I will grind the plunger helix.

To accomplish this, I am thinking of using an old punch press, to push the plunger. I will build a barrel holder that has a fuel cavity like the IP. The press will cycle slow enough,( plunger velocity), to allow me to sample the pressures electronically with out too much trouble. I will be able to vary the speed of the press, (plunger velocity and number of strokes per min.), to get a feel for how much the plunger angle changes in order to maintain a quantity at an increased plunger velocity.

I will also be looking for fuel bleeding past the plunger into the simulated cam case which would contaminate the engine oil in real life.

I am sure this will be a stinking mess, but it is the only way I can think of to isolate the element and each aspect of its operation.

pressure rises immediately. BOD is when the port is closing.
rack position idle is about 5.3 - 5.4 mm, 0.9-1.0 ccm/1000
Important is the max. allowed plunger lift, which is at about half the total plunger travel to avoid cam/roller floating. The max. quantity should be there, not beyond.

Tom

I am on vacation and have a chance to update some progress. I have settled on a 10mm Element for a P pump to modify for my high output MW Pump.

I am going to add an additional fill port on the back side of the barrel to increase filing efficiency. Its placement will be just bellow the original port to guarantee that the timing is controlled only by the original port.

I am also setting up one of my machines to grind the end of injection control edge on the plunger so that the max quantity deliverable, and the rate of increase per degree of plunger rotation, (rack travel), will not be as radical as it currently is, allowing for grater control of fueling, (improved drivability).

I am going to mod the sample element that I have and set up a operational test to run it for extended periods of time to evaluate the performance and life span of the modified element.

I have been going back and forth on how high to set the pop pressure of the injectors. I think I will get a couple of nozzles honed to a certain size and set one at 150 bar and one at 200 bar and evaluate the spray of each to see if a higher pressure has any desirable effects.

take care that the additional supply bore does not get in conflict with the lub grooves and the control edges. Btw. does the plunger reach this bore at all as it is below the original bore? Then when the lower bore is filling the element and the plunger moves upwards it will pump the fuel out of the upper original bore?

The thing I would do is to measure the peak pressure first in the hard line with different nozzles. This will provide an idea whether the volume of a 10 mm element can go through the nozzle within the time at all.

Any information from jeemu on PC bore diameters/modification?

Tom

The new bore will be the same diameter as the original, "Control Bore", and the top of the bore will be located .010 inches lower than the top of the "Control Bore". It will be clocked to be free of the end of injection control edge and lube grooves.

The original, "Control Bore", will be the last to close as the plunger goes up, and the only one that will pass fuel at the end of injection.

This additional hole is intended to provide an additional bore to aide in filling at high speed as this element has a smaller dia bore than the other 10mm elements I have.

I like the smaller bore because it will close sooner, (less plunger travel), and less fuel will be pumped in and out of the element from bore opening, to the start of injection. This will allow for a shorter stroke cam.

I agree. The goal is to be able to controllably deliver fuel in quantities from idle to about 90cc. The issue that concerns me is the spray pattern at the upper end of the delivery range.

It appears that the rate of delivery of your 7.5mm elements with the M pump cam works very well in NA and turbo applications. I am curious to see if there is a magic delivery duration, that if shorter, power is lost. If that is the case. I can reduce the rate of delivery via the cam profile.


Nothing other than his last post.

His 60X prechambers have more 3.5mm holes to drill out than I had in my 617 Prechambers. I did not have a chance to touch the IP before I sold the car, but I did see a reduction in EGTs at high RPMs, and the feel of increased torque when the alda started increasing fuel.

I did not notice anything different about the turbo, but I had stock fuel settings and I think the waste gate was not sealing as it should.

the end of delivery must end before the plunger slows down due to cam profile, that's all.

I increase the supply bore by making an oval. Not wasting effective plunger travel. You can "open" the bore to one side and additionally create a funnel like edge on the outside of the barrel.

Unfortunately the 617a PC are rare and expensive new over here so I did not modify them (up to now).

Tom

What holes are 3.5mm?
Om605/6 engine has 8+1 holes in chamber.

__________________
E21 550hp diesel http://jeemu.kuvat.fi/kuvat/BMW+E21+%28diesel%29/
w202 m104 1000hp with BIG turbo project

Hi jeemu,

what modification did you do to the pre chambers?
We thought you increased the bores to the cylinder to 3.5mm.

Tom

Hi tomnik.

On 605/6 not enough space drill holes that big.
I drill the little ones and the main hole bigger.

http://jeemu.kuvat.fi/kuvat/550hp%20K%E4yttis%20naku/Moottori%20OM605ST/big%20one.JPG/full

http://jeemu.kuvat.fi/kuvat/550hp%20K%E4yttis%20naku/Moottori%20OM605ST/stock%20vs%20modified.JPG/full

__________________
E21 550hp diesel http://jeemu.kuvat.fi/kuvat/BMW+E21+%28diesel%29/
w202 m104 1000hp with BIG turbo project