I don't want to hide information I just thought you should not go the learning path I already went.
The custom MW elements cost me 75 EUR/each and they work perfectly.
In my opinion the good governor operating range gets too narrow when you cut off fuel to let's say 80-100 ccm/1000revs using the 8mm elements.
This is the reason why I am not too much after quantity at all cost but a good relation of quantity within the original range of the governor.
Either the governor gets too sensitive or the car looses drive ability.
Getting 8mm for free and cheap bench access together with a bench freak, o.k. but not if you have to pay for.

Tom

You are a good man.

Governor operation is one of the reasons I want to modify the "Control Edge" to get a different curve. I will only be able to use a minor percentage of the delivery capacity that the 8mms can put out, and I want to be able to use the governor to it's furthest extent tuning wise. I am leaning towards EDMing the groove instead of grinding.

I got a quote for $64.80 ea for an aftermarket Bosch 1 148 415 058, 8mm Barrel / Plunger assembly. Distributor is located in California, but I am sure they are made in China. I am going to ask who actually manufactured them. I am yet to hear from two other possible sources. I have heard rumors of assemblies for under $20.00! Sounds scary to me.

From your experience with aftermarket Barrel/Plunger assemblies, which manufactures are the best and worst quality wise?

I am also going to do some research into the Injector lines and pop pressures that these elements are used, and compare them with the lines and pressures we use, and evaluate the merits of getting the Delivery Valves that are used with these elements.

My concern is that, for example, at idle, I would be moving, (displacing), the same amount, (volume), of fuel, but doing so in 1/2 the time. My thinking is that the stock DV is calibrated for a range of fuel volume, delivered over a period of time. If I reduce the time it takes to deliver the same fuel volume I am afraid the DV will not perform correctly and cause poor idle, smoke, etc.

no problem with the DV. I have compared the DV with ones out of a 10mm MW IP. Also I have directly compared the DV with the orifice and without in the same IP with no difference on the bench. Regarding the collar the DVs of the small 5.5 IP are the best in sense of narrow collar.

I tried several after market elements (at that time M) and it seems to me that they are identical origin.
Take a close look at the control edge. This edge has to be without radius. This is the reason why grinding the hardened part is the only way to do it, no EDMing. Edges with visible (shiny) radius are bad quality. No problem, but the detailed geometry is slightly different and will result in different flows at different rpm and positions. You can not balance them well in low AND higher rpm ranges. Some people live with crappy idle (its a race car) and focus on balancing the high rpms.
Before changing the edge I would rather touch the "gearing" of the governor levers to expand the operation range (let's assume you have good quality elements), but I took the decision that this is more complicated than just making new elements.
The precision of manufacturing elements is far beyond what a good machine shop can do. I also asked those guys but the answer was the same for all of them.
Do a search there was a guy who had 8 mm installed but he stopped posting.

Tom

Well it appears that my first source, (here in the USA), is the best chance I have to get 8mm Barrel and Plunger assemblies. Price is $64.80 ea, and I can buy one if I want. I am sure they are made over seas as they do not have then in stock here in the US, will be 10 to 12 days to get in.

No one else I contacted had any, but they said they would make them if I had a sample. Min order is 500 pcs.

I need to do something with my 616 IP and for $260.00 I think I will order some 8mms and see what I get to work with. It will be interesting to see after measuring the helix geometry what the actual displaced volume per degree of plunger rotation is.

It is easy to say, (and arrogant), because I have not done it yet, but, I am confident that the governor is capable of working just fine with the 8mms, and that I can dial it in. It really depends on the geometry of the controlling edge.

I have searched some what, but could not find anyone that has actually run 8mms. Over at super there is a fellow that had 10mms installed and had brief video of it idling but nothing since.

I have a microscope with a USB camera. I will put the control edge under it and save some pictures for you to evaluate.

I will also have the helixes optically measured, this will create a model of the actual groove, and I will be able to see the sharpness of the edge and how well the groove geometry matches each other. I would do this again if I modify the plunger for quality control.

I am getting some interest in tuning MW pumps, so I will start researching parts to build a test bench.

Just a thought:
before you spend money and time with building a test bench you might want to get these 8mm elements at least adjusted in a shop where you can assist.
In case it turns out that the quality of those elements is not enough you can focus on that and safe the time/money for the bench.
On the other hand your project is highly interesting.

Tom

I was just re-reading everything and a thought popped up at this point.

I am not concerned about the DVs ability to flow fuel, but rather that they do what ever they do for a good idle.

It seems that the idle speed increases slightly with cut DVs indicating an increase in delivery, which can be adjusted back to where it was with the stock DVs, but the idle is terrible. I am thinking the issue is with the quality of the spray pattern. A wider DV collar may be necessary when the pressure rise and fall or delivery is faster? To compensate for stronger or weaker springs?

Question; if you ran a stock IP on a bench as a "standard", and then swapped out the DVs for cut ones and re-ran the tests, would there be a discernable difference in the two readings?

what I am doing (maybe next week, when my bench guy is putting my IP back on the bench again) is to install a different DV into cyl. 1 to see the difference in quantity. But I fear that playing with DV is more a question of spray pattern and timing than just more quantity, or a combination of all.
As said many times before what is going on in the hard lines is more acoustics than physics and a thing to be looked at at a later point.
I just wanted to note that there is no restriction by the stock DV as far as I increased quantity.

Tom

I totally agree.

I have to dig out a spare IP and set it up to map out the cam profile. I want to know how much lift takes place at each degree of cam rotation. That information will be used to determine what, if anything, I want to do with the groove geometry.

Another question for everyone; given that the flame speed is theoretically known for diesel fuel, is it possible to make an excel spread sheet that will show how long it will take specific amounts of fuel to burn, starting with a good idle quantity up to say 300 HP with a 617 bore and stroke?

My interest is in that it would be bad to inject fuel faster than it can burn, as that would allow access, (nonignited), fuel to collect, and a second independent flame front could ignite, and when the two or three flame fronts come together (Detonation).

Don't forget to collect also the plunger rotation over rod position...

Your thoughts about flame front is correct, but (at least in my opinion) not worth and hardly possible at all to calculate.
What I intend to do is to measure the pressure curve over engine crank shaft position. This will give information about the pressure build up, timing and duration of pressure/flame runtime/injection.
There are many parameters such as spray time and pattern and the whole thing with pressure waves in the hard lines.

Tom

I was talking with one of my customers who has a 240D that he races on parking lot road courses mostly. (I tuned up his IP last spring). He is looking to step it up a notch or two and we talked about what the current limitations were yada yada.

At the end of the brainstorming session, he decided he wants to put a turbo on it with an IC, and build a new IP with 8mm elements if they work out, or 6.5mm ones if the 8mms don't. Also the governor would be gutted like a fish. The only governing function we agreed is useful for a "race car" would be the idle governor, the Torque Control and Max speed go by by.

As we talked about the idea it just made more sense. Any fuelling curve control that was absolutely necessary could be done via the ALDA rod, which also would be used to control the throttle sensitivity.

This set up is not intended for road use, (at this point), only closed course, on / off style driving, where the driver is limited to the driver, not the fueling curve happy governor.

This is just heresy until I get a test bench up and running and compare the controlability of governed and non-governed.

I plan on ordering some 8mm elements around the first of March, should take about two weeks to get them in they said. Then the fun begins.

WOW, I have received several inquiries into working on M pumps today! Was it something I said?

On a side note; Thanks to all for PMing you questions. I think that is the best way, although some of you need to make some space in your mail box. I could not reply to two of you.

Again as a disclaimer, please read this entire thread.

I have not worked with M pumps, yet, because I do not have one and I really like the MW's design over the M, and the MW will handle more abuse, (higher Pressure), that the M will.

Question: If I had a "HOT" MW IP with Tomnik's 6.5mm elements or modified "aftermarket" 8mm elements would you consider it over an M?

Yes, yes, yes!!!

After setting up the 603a M-IP with 7.5mm I know what I am talking about.
I wish there is a MW 6 cylinder for the 60x engines.
The reason is the adjustment of balancing the individual timing on both designs.
On the M the rollers have to be exchanged, which means that the cam has to go out. On the MW you just shim the barrel from out side.
On top the rollers are not cheap. Either you have a complete set of them with different diameters or (in my case) you have to measure, calculate and order the necessary diameter (and hope that it is available). The you start from the beginning. An experienced bench guy will do this only once, I had to do it more than one time and most of standard bench shops won't care about.
I learned this when I ordered the rollers.
This also shows how important it is to find a good bench shop. On the other hand the result is only a roughly running engine

Tom

What would be the difference in physical fit to the OM603 engine? Would it require different hardware, injection lines, etc?

First impression is that it means buying another pump vs tuning a known good one. If it's better though, ... depends on the cost.

__________________

Gone to the dark side

- Jeff

I seem to recall being told that the MW has a shorter control collar length than the M pumps and as such it increases its fuel delivery quantity/mm of rack travel more quickly. This was supposedly one of the reasons for building M pumps rather than MW's as the MW's with big plungers became very touchy when on the engine. I know my M pump has a fair bit more travel on the speed control lever than my MW and that helps to reduce the sensitivity as well. Has anyone verified what the control distances are on the two pumps?

One nice feature of the MW IP is the ALDA rod. Basically speaking, moving it up or down changes the pivot point for the rack lever and thus changes the amount of rack travel for a given throttle lever travel. One could use this feature to control the "Sensitivity" of the throttle.

I still have to look, but I want to order the Delivery Valves that the 8mm Elements use and see what the difference is between them and the 5.5mm Element Delivery Valves. If the collar is different there may be some benefit in drivability.

Another thing I would want is to get some extrude honed nozzles. I am thinking around 25% larger area. Reason behind my thinking is given a set quantity of fuel and injection time, with a larger nozzle circumference, the amount the pintel would have to move would be less than with a smaller circumference.

As a result of the reduced pintle lift, the gap between the pintle and the nozzle orifice that the fuel passes through would be tighter which would aid in atomization.

A smaller orifice would require that the pintel lifts higher, making the gap wider resulting in a thicker fuel stream so to speak.

In addition, if you reduce the length of injection time and increase the amount of fuel, I could see a small orifice pintel over traveling from a pressure serge. A larger orifice would be better at releasing the pressure while keeping as tight of a gap as possible.

All and all, IMO one can not change one thing in a balanced system and expect it to still perform as a balanced system.

If one changes one aspect of a balanced system, the other aspects must also be changed to compensate for the first change.