6 new Monark nozzles, spray angles inconsistent with each other - Page 2 - PeachParts Mercedes-Benz Forum

Deplore · #16 05-18-2016, 11:04 PM

Quote:

Originally Posted by scottmcphee

..and everybody knows to keep body parts and fingers the hell away from the spray coming out of the tip, right?! Not getting any ideas about "feeling the spray".

Would pass right through your thin glove, skin.. right to blood poisoning.

Always worth mentioning, if noobies are following along.

The most important info in this whole thread, imo.

I admit it, there is a good chance that I'll be that idiot who might attempt it if I had my own pop tester.

I did the finger test with a pressure washer.... That was an agonizing three weeks. And it was under 100 psi iirc.

....yeah, I'm going to memorize this.

zebellis · #17 05-19-2016, 12:06 AM

Quote:

Originally Posted by Clemson88

Lacquer thinner is a little stronger solvent than diesel. I used it to remove the shipping oil which the nozzles were coated with when they arrived.

I see. I’m already set up to use the carb cleaner and diesel dips, so I think I’ll do that. Perhaps I can find a paper-type filter to pour some diesel through to filter it. Any reason that people talk about filtering the diesel fuel, and not any other solvents or cleaners used?

Quote:

Originally Posted by Clemson88

The main thing is that you make sure the needle valves will drop half their length under their own weight inside the nozzle body. On some of them I had to give them a little help during the first trial but found that after the diesel was somewhat purged/pushed out of the nozzle they all dropped just fine. This will ensure that they are free of contaminates.

The sensation of fine “grinding” while lifting and reseating the needle from the nozzle was unusual. I had the thought that perhaps it was not grinding, but instead the feeling of lots of tiny rapid-fire “pops” caused by the trapped air or liquid purging from the space between the needle tip and the seat. I can’t remember now, but I think it went away after a few attempts to get it to “drop” freely on it’s own. I will repeat this after I open them all back up and clean them, and pay more attention to this behavior.

Quote:

Originally Posted by Clemson88

Some of the steps and procedures I took seemed like outrageous overkill but it was my first trial at this activity and I didn't want to learn trial and error. I'm sure someone who does this regularly could have spent much less time but they all popped at exactly 1975 psi and have operated trouble free so far. I lapped the body seat before I gave them a first pop test then again to fine tune the popping pressure after making shim additions to just under my pop pressure goal. Ridiculous.

At what pressure did you get the injectors to pop?

I felt like I was going a little overboard with the cleanliness too. I started wondering if all the warnings for surgical cleanliness are to be taken in the context of how clean we tend to be while working on the rest of the car. I took it seriously nonetheless.

My pop pressures are:
1: 2025
2: 2025
3: 2010
4: 2075
5: 2025
6: 2010

zebellis · #18 05-19-2016, 12:09 AM

Quote:

Originally Posted by BillGrissom

Most of your questions are at the engineering research level. I used to work in spray research long ago. You could review the ILASS and ICLASS seminar papers in a university library for detailed info. I will relate just a few things. In-cylinder high-speed video showed that the spray cloud from ~1990's diesel injectors (pop style) would impact the far cylinder wall. That was thought to be a big cause incomplete combustion, thus soot. This was in big truck engines, w/o a pre-chamber.

The current "common rail" systems raised injection pressures from ~2000 psig to >10,000 psig. I understand that was mostly developed by Fiat, and I recall many Italian researchers at conferences then. The result is much finer atomization and spray presumably not impacting the cylinder walls as much. You rarely see trucks smoking today (plus exhaust traps) and they are more efficient. In car diesels, that allowed tapering the initial injection to minimize pinging and thus get rid of the pre-chamber, greatly increasing efficiency. Thus, atomization is most critical.

The spray in your engine at >400 psig will likely look different than in the atmosphere, since the gas density is much higher. But, what you see in the air is still good for comparisons between injectors. My experience is similar to others. To get an injector to chatter with the machine-gun sound, requires fast motion of the hand lever. When an injector streams continuously instead of chatters, it is usually more due to your stroking technique. Try again and you can usually get it to chatter. I see fairly narrow spray cones (~20 deg included angle), at least as best I can see thru the cloud of droplets. It is quite forceful and will knock a container over. I put screen in the bottom to avoid splash-back. To quantify the spray cone, one would need a video setup, probably w/ 2 cameras at 90 deg.

This is all very interesting info. Thanks Bill! As for the actual spray cone, I’m really reluctant to get my camera lens too close to the spray, especially with the risk of lateral streams (though I think I understand better now how to avoid them). I wonder if I could set some fabric at a fixed distance from the nozzle tip that would leave a clear mark from the sprayed diesel. The shape of the mark could help determine the angle and general cone shape - when used in conjunction with a visual inspection.

zebellis · #19 05-19-2016, 12:10 AM

Quote:

Originally Posted by scottmcphee

..and everybody knows to keep body parts and fingers the hell away from the spray coming out of the tip, right?! Not getting any ideas about "feeling the spray".

Would pass right through your thin glove, skin.. right to blood poisoning.

Always worth mentioning, if noobies are following along.

Thankfully, I was aware of this risk beforehand, but you are absolutely right, it should be reiterated whenever this topic comes up - thanks! I would also like to add that a face mask would be a good idea. I did all my testing outside, but I think I still managed to inhale some fine diesel mist. I didn’t notice it right away, but I eventually started feeling a burning sensation in my throat. It persisted all day but was gone by the next.

zebellis · #20 05-19-2016, 12:18 AM

Quote:

Originally Posted by jt20

To better understand some of 'this' better: do some searching on this forum for 'prechamber modifications flame front'

I forget the actual threads and users involved, and much of it should be taken with a cautious attitude, but an interesting investigation with lots of great data to say the least. - a good starting point for further research if you are so inclined.

Thanks - I’ll look into that. So far the only thread that comes up with the exact search term you quoted is this thread!

I found a bunch of others though when I dropped the 'flame front'.

zebellis · #21 05-19-2016, 12:28 AM

Quote:

Originally Posted by Diesel911

I am curious why the Fuel Injection Shop did not say if they thought the spray patteren usable or not?

Back something like 5 years ago there was a period where the Monak Nozzle quality took a plung and for close to a year no Nozzles were being sold here.
When the nozzles returned that problem was apparently fixed.

I bought about 40 nozzles totaled and had one that was extremely bad and it projected a figur 8 type pattern.

Each 2 parts of the Injector Nozzles are a mated assembly. If you mixed parts between the Nozzles you can get the situation that you have.

If any grit got into the Injector Nozzle that can damge the seating area of the nozzle.

Both of the items I mentioned above can cause the Injector Nozzle to pee out before reaching the opening pressure and or effect the spray pattern.

The test for the nozzle seating areas is to find out the opening pressure of a particular injector and set it correctly if not so. Then you slowly bring up the pressure till it is 200 psi before the opening pressure you recorded. At that point you are allowed x amount of drips per x amount of time (I don't remember specifics).

A really excellent Injector Nozzle will not drip all they way up to the opening pressure and then open and spray suddenly.

The fuel injection shop did not have a comment on whether they were usable or not, he just was surprised at the difference between the 3 narrow angles and the 3 wider angles. He acted like he had never seen that behavior from a set of new nozzles. He mentioned that part of the number stamped on the nozzle holder was supposed to indicate the spray angle, and therefore they should all be the same.

vstech · #22 05-19-2016, 01:16 AM

Quote:

Originally Posted by scottmcphee

..and everybody knows to keep body parts and fingers the hell away from the spray coming out of the tip, right?! Not getting any ideas about "feeling the spray".

Would pass right through your thin glove, skin.. right to blood poisoning.

Always worth mentioning, if noobies are following along.

Quote:

Originally Posted by Deplore

The most important info in this whole thread, imo.

I admit it, there is a good chance that I'll be that idiot who might attempt it if I had my own pop tester.

I did the finger test with a pressure washer.... That was an agonizing three weeks. And it was under 100 psi iirc.

....yeah, I'm going to memorize this.

Memorize THIS... It's not just blood poisoning...

It's INCURABLE BLOOD POISONING... Needing AMPUTATION TO PREVENT DEATH...

Diesel911 · #23 05-19-2016, 04:00 PM

Quote:

Originally Posted by zebellis

The fuel injection shop did not have a comment on whether they were usable or not, he just was surprised at the difference between the 3 narrow angles and the 3 wider angles. He acted like he had never seen that behavior from a set of new nozzles. He mentioned that part of the number stamped on the nozzle holder was supposed to indicate the spray angle, and therefore they should all be the same.

If they were mine I would serious consider sending the nozzles back to the Seller.

One member rebuilds Injectors. Perhaps he would comment on the issue.

If you take an Injector Nozzle and pull out the central Pin/Pintel/Needle and look at the bottom of the Nozzle at the hole with a magnifying glass the hole should be perfectly round and all of them the same size. If it is not round or some holes are wider then others the spray is going to get wider and or uneven.

Clemson88 · #24 05-19-2016, 06:24 PM

I would be surprised and disappointed if any manufacturer produced a lot of 6 injectors which included 3 bad ones. I could not tell the difference between the spray patterns of the five Monarchs I installed.

Silk is a fine enough material with which to filter diesel for pop testing. I just didn't happen to have any silk or I would have used it rather than breaking out the mityvac and using a primary filter for the process.

97 SL320 · #25 05-19-2016, 07:53 PM

Quote:

Originally Posted by zebellis

The fuel injection shop did not have a comment on whether they were usable or not, he just was surprised at the difference between the 3 narrow angles and the 3 wider angles. He acted like he had never seen that behavior from a set of new nozzles. He mentioned that part of the number stamped on the nozzle holder was supposed to indicate the spray angle, and therefore they should all be the same.

Were the nozzle holders 100% new or just the nozzles themselves? On the ( actual Bosch ) nozzles I got for the tractor there were numbers on the sides. You should have these also, they may or may not be visible without taking the holder apart. The numbers on the holders only matter if they were never rebuilt.

Dan Stokes · #26 05-19-2016, 08:45 PM

I got my 315 Monarks, assembled, from Greazzer and left it up to him to make everything alright. Judging by the dyno numbers, he did!

Dan

jt20 · #27 05-19-2016, 10:32 PM

Quote:

Originally Posted by Dan Stokes

I got my 315 Monarks, assembled, from Greazzer and left it up to him to make everything alright. Judging by the dyno numbers, he did!

Dan

I'm surprised greazzer hasnt chimed in here. I'd love to hear what he has to say about the current Monarks.

He's probably seen more of them than any of us; that we know of publicly.

jt20 · #28 05-19-2016, 10:35 PM

Quote:

Originally Posted by zebellis

Thanks - I’ll look into that. So far the only thread that comes up with the exact search term you quoted is this thread!

I found a bunch of others though when I dropped the 'flame front'.

oh... it may be in forum "diesel performance tuning' and not automatically searching them concurrently when you are trying.

but its good to know you're on the front page now!

jt20 · #29 05-19-2016, 10:41 PM

Prechamber modifications

found it. Good 'ol OM616... great info / theory here. Must do your own investigation beyond this thread - there's some sketchy info in it.

zebellis · #30 05-20-2016, 11:56 AM

Quote:

Originally Posted by 97 SL320

Were the nozzle holders 100% new or just the nozzles themselves? On the ( actual Bosch ) nozzles I got for the tractor there were numbers on the sides. You should have these also, they may or may not be visible without taking the holder apart. The numbers on the holders only matter if they were never rebuilt.

I bought new nozzles for my old injectors, which only included the nozzle holder and needle, and my understanding is that the holder and needle MUST always be paired together. The numbers on these new nozzles are in my first post (525 MDN, 39 305 128, and 0SD 265), they were on the outside of the holder, on the upper collar. I have the old ones still. They were Bosch with the following numbers on them: 645, 060, DN 0 SD 265.