Some years ago, I did some tuning on my CAT engine, with a lot of injection shop help, and one improvement was a different IP with a more aggressive cam = higher injection rate, which was developed for lower emissions. Am I clueless for thinking that Bosch/M-B did the same for the same result?

I understand that same hp = same flow, just at lower RPM so probably same lift and definately the same 5.5mm elements. Timing device is the same too, so I'm also wondering if the timing is the same in the cam grind.

Just got a quote from a different source. 8mm (MW) Barrel and Plunger assemblies for $12.50 ea. I have asked them to quote some 10mm ones. (Edit): $13.50 ea for the 10mm.

This is from a different manufacturer that the gentleman over at STD purchased his from, (from my understanding).

I plan on ordering some 8mm elements from both vendors, test them head to head and see how they compare.

If the $12.50 ones check out, it would cut the cost to build a hot MW dramatically, as I am most likely going to have them modified along with the cam, and the costs add up.

On another note I am considering rebuilding my engine dyno for performance testing. The biggest hurdle is finding a CHEEP engine that is not shot to use as a test bed.

With a working dyno, all my pumps would be performance tested on the dyno before approval for shipment.

I had a chance to work with an M pump yesterday and I am not impressed with the design, it is definitely designed to be slammed together on an assembly line. I can see having to grind every roller to get the start of delivery deviation as close as I want it to be.

As a result, I am not going to be working with any M pumps. It sounds like Tomnik's guy is the best option, (at this point), to have am M pump modified. I am going to focus on the MW pumps.

I have received prices from three different, (China), manufacturers and will be ordering sample 8mm MW barrel and plungers, (elements), from each one to compare quality.

I have a line on a Bosch 8mm element, but even at a discounted price it is still up there. I may get one to compare the others to but that will be determined by my funds at the time.

To everyone with an M pump that contacted me, I do appreciate the opportunity, but at this time, I am not comfortable enough with them to play engineer with someone else’s M pump.

As for the MW pumps; I think they are a much better design. Plus, I think they will take a lot more abuse, (higher pop pressures and larger elements).

I have two local shops that can handle the plunger, barrel, and cam mods, so I am hoping that when I have the changes figured out, it should come together quick.

My 616 pump has one element that puts out more fuel when cold than hot, so I will do that pump first. Plus it is easer to get in the governor for tuning. I have a VNT to hang on the exhaust at the same time, so that will add some additional variables, but nothing unmanageable, IMO.

Proper planning prevents piss pore performance.:rolleyes:

Cool, a hot mw!

My words!
There are different rollers available from Bosch to adjust the pre-lift, but the cam has to be out to change them. If your measurements and notes are not good you might do the cam disassembling more than 2 times...
Start of delivery is set by fixing the counterweights at a certain position on the cam (before that the pre lift adjustment has to be correct).

Tom

Yes, one is limited to the availability of roller sizes. If you need a roller that is between a size step, you will have to decide which way to push the timing, (the roller on the tall half will advance the start of injection on that element, and the roller on the short side will retard the start of injection on that element). I guess it comes down to how precise one wants the setup to be.

In addition to being limited to the roller size steps, the rollers are expensive and one would have a lot of money invested in inventory in order to have the range of sizes that could be needed when moding an M pump with different elements.

Too much of a PIA IMO.

I am also not a fan of the Bosch method to determine the start of delivery.

I set an 616 MW pump up in my rotary table and, using the Bosch method determined the start of injection on the #1 element, and set a marker on 0 degrees. I then rotated the table and determined the start of injection on the other elements and noted the degree reading. Now it should be noted that this is a used pump, but there was a three degree spread, (from highest to lowest), and that is at the pump. That would be twice that at the crank.

To be sure I was doing it correctly, I reviewed the Bosch service manual and an International Harvester service manual for an MW pump, and repeated the process. I compared the two, (Bosch method), readings and they were within 2min of the first reading.

Then I tried it my way. I measured the #1 plunger height, (3mm lift if I remember right, would need to reference the service manual to refresh my memory), and set a marker on 0 degrees. I then rotated the rotary table, and stopped at every 90 degree mark, (I have a certified table with a 10 sec vernier, and a certified .0005 inch dial indicator). I noted the plunger height of each element. I then disassembled the pump and measured the distance from the top of the barrel to the top of the fill port.

I then compared the two measurements for each element. I found that the 90 degree plunger height deviations corresponded with the observed (Bosch method) trends.

I then reassembled the pump using the fill port height of each element as the plunger lift speck and shimmed each barrel to achieve each speck at their respective 90 degree increment. I made custom shims to set each barrel with in .0005 of the fill port height that was measured earlier.

I then did the Bosch method and noted readings within 2min of each 90 degree mark.

I took the pump to a Bosch shop, (my bench is not ready yet), and they balanced the fuel output. I put it on my friends 240D about a month ago now, (his pump was ruined by water in the fuel), and he said that it has never run so smooth.

I like using actual measurements instead of cresting fuel, what a stinking mess. When I installed the pump I set the timing via the plunger height instead of the drip method. I think that is how the VE pumps are timed as well.

Now I am sure I am going to get some flak for this, then again the earth was once the center of the universe and flat too.:P

physically correct is only the drip method. They pump fuel into the gallery with removed DV and rotate the cam until the flow stops.
Measuring the plunger height is more clean and obvious but I would prefer the flow method.
On the other hand I have talked to several Bosch shops and they usually don't use different rollers. "Are yours damaged? Or why do you need them?" This was their reply when I asked for rollers of a certain diameter.
It is simply too expensive to set up the pump precisely and the huge tolerances that Bosch allows for individual start of delivery supports them.

Exactly for this reason it is important to find the right partner or just do it on your own.

Tom

Just so I completely understand, are you saying that; ("It is simply too expensive to set up the pump precisely and the huge tolerances that Bosch allows for individual start of delivery supports them"), however you have found a partner who will, "set up the pump precisely", without being "too expensive"?

I only ask because my understanding of your goal is to build as precise and highest quality of a pump as possible, but the first statement states that anything better that OEM tolerances with an M pump is cost prohibitive.

Cost is the first thing that I thought about when I looked at moding an M pump. There is no way anyone would pay what I would have to get to cover my time and parts to get the M pump up to my tolerances; (Fill port closure plunger height +-.0005 inch @ degreed location +- 10sec), I haven’t worked out my delivery quantity tolerance yet as I haven’t completed my bench yet. I am working on the data collection system now.

I don’t mean to bust your chops, but I have told a few people that your goal was perfection, as is mine. I just want to be sure I know where of I speak.

Dave

... too expensive (and not precise enough for me) to find a Bosch shop.
Less expensive (not cheap yet) would be a guy that has a bunch of rollers and the skills and experience to take off the cam only once (maybe twice) and all the necessary tooling but not at the labour cost of a Bosch shop. On top this guy has to identify himself with the project and not just waiting for the weekend or end of the day.
Most shops are looking for max profit instead of doing something interesting.
I spoke with many shops, some people showed interest but not their bosses.
I still don't make any compromise in quality (this is why things take so long) but I also don't pay any price.
Look for a bench guy that kind of depends on you in some way and you will get what you want at reasonable cost.
I also tried to get in Mercedes or Bosch development/training centre but they play computer and lost the relation to the basics. Same with universities etc.

Tom

Correct, but on the other hand they are working on the future.
Our knowledge let's say 10 years earlier and we could probably do something in terms of emission reduction...
There are very few people who are able to understand the old stuff (and they disappear more and more). The kids have no interest.
When looking for a VTG boost controller I met a young guy working in Bosch training centre and I expected some progress but he does not even have a car!!
When he asked me how in general a turbo works with his hands deep in this pockets, thanks bye bye.

Tom

I am ordering elements from two China manufacturers this week. I am curious to see how they compare to each other.

I went to order the $12.50, 8mm elements and they were out of stock and were not planning on making any more soon. I did not check the $64.80, 8mm for stock.
Due to the rare nature of the 8mm elements, I will be modifying 10mm elements as they are plentiful.

One company has 10mm elements for $13.50ea and the other @ 11.85ea, with $50.00 shipping for each company.

I now have a sample 10mm element that I will take to the grinder today to physically show them what I want to do.

I figure I have another 6 hours of figuring before I will have the specks to have the barrels and plungers modified. My output target @ 85% rack travel is 90cc per 1000 strokes.

I will also be able to cut down the cam a bunch which will help with higher RPM operation.

I'll be interested to see what you come up with. My biggest worry with China vs. Bosch elements is metallurgy, although fit & finish is also important.

Please keep us posted on what your ideas about cam profiles/heights are. I'd worry about blindly messing with the injection duration. There are a lot of variables in this. Really getting the big elements to run right will probably have something to do with a customized timing advance device.

As for you guys (tomnik and OM616) talking about how nobody knows anything anymore... I agree people want quick, thoughtless money. A shop wants to do something they have done 1000 times before, they want to know their profit margin ahead of time. Its near impossible to get anything "custom" done for a reasonable amount of money, and most of the "custom" guys are B.S. anyway.

I don't agree that mechanical governors are the way to go, but until I've acquired some hardware to play with, my hands are tied on that one. I'm hoping to have something rudimentary by the end of the summer.

Electronics could make MW pump tuning a heck of a lot less expensive, more precise, and yield better running engines.

Any updates?

Well I ordered 10mm elements from two different manufacturers, 10 elements total. They should be here by the end of the month or early next month.

I have spent some time at the grind shop talking with them about the best way to set up the plungers in the grinder. It turns out that I have the same grinder that they would recommend using, so I may vary well be able to grind them myself once the process figured out.

They will be grinding the cam though as they have a CNC grinder that will be able to maintain the lobe profile geometry only with a reduced lift radius.

I have done some preliminary calculations that get me in the ball park so to speak regarding total delivery quantity and corresponding required stroke. After seeing unmodified 10mm elements run in a 617, I am confident that I can get the results I am looking for, but the proof is in the pudding.

I am trying to figure out the best way to eliminate, or lock, the timing advance mechanism with it in the engine. I have not seen one, any ideas?

I still have to look at some things, but it might be necessary to make it work backwards, as a timing retard instead of advance because of the incredibly short delivery duration.

I can imagine that statement will raise some questions, but it would be very helpful if thoughts were focused on locking the timing device or making it work backwards regardless what one thinks about the idea. The discussion as to the merits of this modification will be discussed later when the time comes as it is a theory subject that will take on a life of its own.

My goal is to keep on point. I hate threads that separate progressive logical thought into chunks, because of tangential sections, or argument of a parallel aspect, that is best placed in a different portion of the thread.

Don't get me wrong, feel free to post, just please try to be mindful of whether the post coincides with the current subject, or if it would be better to hold off until the time if right.

If in doubt, do not hesitate to PM me your thoughts.

I never had a timing device in my hands but I think you could fix the moving part just with a bore and screw for a first test.

Could you please explain how you intend to grind the cam?
You know that the plunger speed is designed for low speed during filling the element then increased speed during injection and decreased speed closed to the TDC all in relation to the fuel supply bore of the barrel.

Next: grinding the plunger? Reducing effective stroke also means taking care of the location of the bore plus adapting this range to the speed/stroke range (cam profile). Are you planning to relocate the supply bore in the barrels?

Tom

Yes that is correct. Because the 10mm plungers have such an incredible volume displacement per increment of plunger lift compared to the 5.5mm ones, and the comparatively minimal amount of fuel that is required, (even at full power), for my application, the actual required productive plunger lift, (after fill port closure to the point where the helical groove is uncovered ending injection), will be less than .075 inches, closer to .050 inches (aprox 1.9mm / 1.2mm).

If the start of injection, (fill port closure), is at .118 inches, (3mm), of lift, the combined total required lift, (not taking into account the deceleration ramp), would be .193 inches, (4.9mm).

I do not see any benefit in continuing to lift the plunger, pushing fuel out of the barrel, only to have to suck it right back in, creating all kinds of turbulence in the IP in the process and reducing high speed barrel VE.

One way to visualize what I am going to do is to imagine removing the portion of the acceleration lift ramp, between the end of injection, (at full power), to where the deceleration ramp starts, resulting in the deceleration ramp starting at .193 inches, (4.9mm), of accelerated lift. This will allow additional time for the fill port to be open, and, since only the quantity of delivered fuel, (plus any leakage), needs to be replaced, the high speed barrel VE should be improved and turbulence in the IP reduced.

Now because the acceleration ramp is so short, the plunger will not be going as fast as if it were lifted to the full stroke, so I may look at altering the deceleration ramp to reduce additional unnecessary plunger lift, but the 10mm plunger has more mass, so the stock 5.5mm deceleration curve might be good. I have not gotten that far yet. I have designed and developed valve train camshafts in the past, but the geometry of the IP cam is unique. Ill have to through it in the computer and see what it looks like.


No. I am going to alter the Plunger Helix Angle, leaving the fill port alone. The new angle will reduce the max displaced stroke distance, and spread the fueling out over the entire rack travel range.

Regarding injection timing;

I think I am going to have to grind an angle on the top of the plunger to progressively delay the start of injection as the delivered fuel quantity is increased with rack travel. (I know that is not written well)

Because the injection pulse width is going to be so short, I think the injection timing will have to be adjusted to match the quantity of fuel delivered to achieve the desired pressure curves at different engine loads.

I have found that my 616NA and 617 turbo want as much advance on the bottom end as I can give them, but, as the bottom end torque increases, the top end power suffers because of the additional advance from the advance mechanism, the pressure curve is too high too soon. So I have to back off the timing on the bottom so the engine will start easily and run freely at full power.

5.5mm elements take so long to deliver the fuel at full power that the pressure curve can be relatively optimized with a lot of advance, but with the 10mm elements, 100% of the full power fuel would be injected in less than, (guestimateing here), 10 crankshaft degrees as apposed to 25+ crankshaft degrees with the 5.5mm elements.

Still have a lot of thinking to do, but I want to have the low power, (low delivered quantity), timing around 25/28 degrees BTDC, but at full power, I can see delaying the start of injection to around <15 degrees BTDC.

It should be noted that I am modifying the Prechambers as well, and that the above injection timing guestimets take into account the observed altered Prechamber affects.

The only way I can think to vary the start of injection timing proportionately with the delivered fuel quantity is to grind the top of the plunger, and have the helix angle correspond to end the injection at the desired quantity respectively.

big task of grinding the cam an plunger helix.
But if you have the possibilities and enough "test plungers and cams" why not.

I don't agree with you regarding the timing.
Imagine the inner cylinder pressure curve of just cranking without injection.
Starting from BDC (valves are closed) the pressure rises and peaks at TDC.
After TDC the pressure decreases. Simple pump following the sinus of the crank.
The compression means energy into the machine.
Now injection is added:
The later you inject (of course always before TDC) the better, the higher the compression temperature is therefore better start of burning.
The start of burning has a fuel specific delay in such a way that the peak of pressure (now an addition of pure compression and burning) is at or short after TDC. In any case not before TDC because this increases the energy you have to put in. This will be the case when timing is too early. The engine is not willing to rev up easily and is nailing. Combustion pressure is against the upwards movement of the piston and injection starts at a point where compression/temperature is still low.
The retard edge of the plungers is just a way to correct the too wide range (in sense of crank rotation) of injection to avoid too late end of injection at load.
With larger elements the duration of injection is, let's assume 50%.
Imagine to shift this range in such a way that you inject as late as possible without getting black smoke or other negative things like bad starting.

Extremely speaking: With larger elements your end of injection might be before TDC, meaning your pressure curve has its majority before TDC, the engine will not run. Ideally you inject just before TDC (pilot "light" the fire) and main inject into the pilot "fire" while the piston moves down keeping a constant pressure (pressure rises because of thermal energy vs. pressure decrease because of mechanical expansion).
Now with your extreme short injection it gets hard to burn well. You might distinguish the fire or get incomplete combustion.
This is the reason why today they have multiple injection with a desired duration of injection while the piston moves down.

Tom

The pressure peek sweet spot directly correlates with the length of the stroke and connecting rod length along with the piston dia. Additionally as you mentioned, the length of time it takes to burn the fuel, and area that the combustion radiation has to travel, (and decay), also needs to be considered. Plus, the quality of the injection and combustion chamber shape and environment, (temtretures/pressures), have influence also.

To help with the injection quality, I am going to open up the injector nozzles in an effort to maintain as tight of a gap between the pintle and the seat during injection, while allowing a high volume of fuel to be delivered is a shorter period of time. Also, I am going to set the pop pressure to 200Bar. The goal being a very very fine injection that is ready for combustion without additional atomization efforts. Whether this can be accomplished with the "vintage" parts is yet to be determined.

My understanding is that there are two phases to combustion pressure. First is the actual combustion, where the fuel is converted and expands into a super heated gases, at the same time, the radiation from the combustion it self heats the surrounding gasses causing them to expand as well. This is one reason why the Prechamber design is not as efficient, as the area of the cylinder combustion chamber is isolated from most, if not all of, the combustion radiation, resulting in a cooling of the Prechamber gasses as the heat is absorbed by the cylinder gasses in an attempt to equalize the over all gas temperature.

Thermally isolating the combustion areas from the surrounding metal would have a big effect on the pressure curve as well. The next batch of Prechambers will be coated with a thermal reflectant.

This subject is very theoretical. Personally, I have gotten the best results from testing the different settings and to see what the engine its self wants. I have an engine dyno, but not an engine to run on it.

As I said, I still have a lot of thinking, and math, to do before I start grinding the plungers. I may be trying to get too greedy, wanting the best bottom end and top end as possible. Electronics are the ticket for that!!

I think it would also be a good idea to get a cam from the 10mm element IP to see if there is anyting that can be learned from it.

Unless they are the same?

I just sold the 300D that was my guni pig, so the development projects are essentially over until I find another one.

I was at the gas station and a guy asked what year it was. When he saw it was a 4-speed he offered me $4000.00 for it. I said 4500.00 and it is yours, thinking he was BSing, but he said done!. We went to the bank, I signed the title, pulled the plate, and away he went.

Now I just have the 240D that is getting a VNT before any IP work. The good news is my mortgage company is happy.

How about experimenting on the 240D pump....?:D

Apart from the VNT, what else have or are you doing to the 616?

You live in Michigan. "Your" mortgage company will be happy when they forclose, get .30 on the dollar, and invest it overseas.

Quote:

Originally Posted by Alastair (Post 2471201) How about experimenting on the 240D pump....?

That one was in line once I had everything figured out on the 617, but since the 617 is now gone, things will be progressing slower and more cautiously. My 616 IP has a week element, so I intend to address it with the modded 10mm elements.


I have turned up the IP and advanced timing.

I installed a stiffer spring in the lift pump and I am running @ 30 PSI.


Made an in-line thermostat housing that uses Small Block Chevy thermostats so I can run a 160 degree thermostat as well as pick one up at any drug store.

I had a M90 blower on it for about 1000 miles,(running 6 lbs), but it was so obnoxishley noisy I removed it and made an resonant chamber intake with a long air intake snorkel to the Air Filter, (improved torque).

Cherry bombs in place of mufflers, 300D aluminum fan and fan clutch.

I have a 2056 (liberty) turbo and air to water IC to put on it.

I want to advance the cam some.

Custom Prechambers are also on the list.

I am making adaptors that will allow me to use standard 300D pence glow plugs in place of the loop plugs.

Hmm, Thats pretty heavy duty work for a 616!

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

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?

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.

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

Thanks jeemu.
That is also my plan as soon as I get some 617a and 603a pre chambers for cheap.

Tom

I have to make a decision as to which way to go. I have some funds that I originally intended, and am trying, to use to buy a solid 123 body to transfer my 616 into, but every deal seems to fall through either because of me or other reasons, and I am starting to think I am not supposed to make that purchase right now.

The other option is that I can build the IP calibration set-up and build a super 10mm MW IP. Then I say to my self, yah, another machine that I'll only use once, and then it will be sitting around, that is just what I need, NOT!

Then again, with the calibration equipment, I could do a few MW IPs to get the machine to at least pay for its self. But that would be a wase down the road as no one has faith in a "Home Built" IP anything, unless it is proven time and time again, and I have better things to do.

I have selected a specific 10mm element that I will be using and have a couple spare 616 IPs, it is just a matter of cash and time. I am tempted to build two 616 IPs but then again, why tie up money on the shelf?

I am going to grind my IP cam to match the reduced lift needs that the modified 10mm element needs so there is extra cost, but if the cam was not modified, then the only costs would be the elements, about $18.00ea plus shipping (figure about $140.00 for a 617), and then they need to be modified at a cost TBD. Bearings, gaskets, springs (I will be using stronger springs), cleaning, reassembly, and tuning costs need to be considered as well.

The elements may run fine as they come though. One gentleman has proven that a different 10mm element will run fine in a 617a. The elements I have chosen put out less fuel than the ones he is running, so it may be practical to just install them with the stock cam, and tune for a cheep hot rod MW IP.

Times are tuff here in Michigan and anything that could possibly provide income is a good thing. But times are tuff everywhere so people are reluctant to spend money on non essential things.

I’ll probably end up just paying the mortgage.

Any advice or thoughts?

Well they would put out far more fuel that the lil 4 cyl could possibly use -wont they? you have to pay someone to set the pump up -or are you tooled up? do you know---PM

There is more to element size than just possible deliverable volume. Tomnik has reported very good power and mileage increases with 7mm elements on a 617 NA without increasing delivered quantity. This is the result of the larger elements ability to deliver the same quantity of fuel as a smaller size one, but in a much shorter period of time, (end of injection can be several degrees before TDC, which enables more of the fuel to be used for work instead being wasted.)

The 10mm elements I have chosen have a leaner, (for lack of a better description), end of injection control angle to start with than other 10mm elements I have looked at. I will be modifying the control angle to further reduce the deliverable capability of the element so I can use the full range of the rack, (should make for good drivability and smoke control).

It may be possible to run these elements as they are, but that will require some testing on the calibration bench and in car. I have an engine dyno just don't have an engine to play with.

I have a VNT turbo that I will be putting on my 616 with the hot pump so I will have mine set for more fuel than an NA one would be.

I have built one MW IP for a good friend that road races a 240d. I retimed the elements to a much tighter tolerance and eliminated the Torque control and High Speed governors. The only governor that still is working is the Idle governor. For that one I took it to a local shop to have them balance the quantities.

I have designed a calibration bench that will have digital interfaces for fuel output, RPM, rack position, Throttle position, and Lift pump pressure. This will allow me to graph the fuel curve of a pump and set multiple governors to match a graph of choice. Most of the IP adjustments I have done for street cars have been more a mater of shifting the fueling curve than actually increasing the max quantity, (full load).

That is true. Faster injection is better all the way. When i change 7mm to 8mm egt:s drop 100degrees. Also that extra power is good :)

I want to have a pump modded to anything more than stock....it can be mw or m i dont care and i cant get both pumps locally, but i need someone to tune it.

Who can do this? Im in california and i have talked to tomnik and the person he pointed me to will not respond.

Anyone have any ideas?

I have a 617.925

Pacific fuel injection or it may be called Pacific diesel injection? In the bay area.

anymore info? thats awesome!

Pacific Fuel Injection Service
153 Utah Ave, S San Francisco, CA 94080-6712
(650) 588-8880

They installed some Chinese made 10mm elements on a MW for this fellow.

http://www.superturbodiesel.com/std/10mm-element-thread-t-716.html

And should be able to install tomnik's elements.



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Thats good to know--i thought it was a M that they did and was gonna get the spare M for the contingency plan -because there seems to be a communication dilema with the outfit elsewhere in the US. -hasnt botherd responding to me either.