My Injector Project and What I’ve Learned

Wow.. Good information here..

Lotsa bull**** too.

The only thing I want to add, is that I think it is funny that some how truck or tractor nozzles are crude, and that people don't have $400K to spend on a machine, I personally know several SMALL business owners that spend that kinda money every year just to go racing, let alone, on something that makes them money.

Upgraded injectors for direct injection diesel trucks have been produced since the early 90's The first VW TDI available wasn't till the late 90's, so with out taking into account tractors, that is nearly a decade more R&D time. Unlike the TDI market place where there are 3 maybe 4 injector manufacturer's there are at least a dozen aftermarket injector manufacturer's in the truck and tractor world. You think that after nearly 3 decades of competition that some how there technology isn't as good as TDI injector technology?

TDI's are small money, TDI injectors are small money, TDI R&D is small money. I have held in my hands a billet injection pump for a competition tractor that worth the same $$$ as a new TDI. It was in the pits for a spare. In the TDI aftermarket people balk at spending $2000, in the truck world that doesn't even get you a transmission.

To me the most ironic part of all of this is; the highest HP vw tdi in north america runs a set of custom edm'd cummins nozzles in machined TDI bodies, from neither of these vendors. Oh and just because you don't know about it doesn't mean its not out there.

Nick, I am glad that you posted the information, it doesn't mean much to me other then relative sizing, but any information is better then no information. The one thing that I feel was missed was spray angles, as this has a big impact on injector performance. Unless of course all of the above injectors use the same spray angle.

To finalize what has become a bit of a novel, I don't run either of these vendor's injectors. I am just sick of hearing how aftermarket truck injectors are some how inferior to aftermarket TDI injectors.

Interesting thread. Makes me more comfortable with running the Bosch product vs. jumping on the Bosio bandwagon.

I'd like to see a heads up comparison of the Bosch .205 & Bosch .216 compared to the same size Bosio nozzles.

Very well put. I'm glad someone else said it

dvst8r said:

The only thing I want to add, is that I think it is funny that some how truck or tractor nozzles are crude, and that people don't have $400K to spend on a machine, I personally know several SMALL business owners that spend that kinda money every year just to go racing, let alone, on something that makes them money.

Upgraded injectors for direct injection diesel trucks have been produced since the early 90's The first VW TDI available wasn't till the late 90's, so with out taking into account tractors, that is nearly a decade more R&D time. Unlike the TDI market place where there are 3 maybe 4 injector manufacturer's there are at least a dozen aftermarket injector manufacturer's in the truck and tractor world. You think that after nearly 3 decades of competition that some how there technology isn't as good as TDI injector technology?

TDI's are small money, TDI injectors are small money, TDI R&D is small money. I have held in my hands a billet injection pump for a competition tractor that worth the same $$$ as a new TDI. It was in the pits for a spare. In the TDI aftermarket people balk at spending $2000, in the truck world that doesn't even get you a transmission.

To me the most ironic part of all of this is; the highest HP vw tdi in north america runs a set of custom edm'd cummins nozzles in machined TDI bodies, from neither of these vendors. Oh and just because you don't know about it doesn't mean its not out there.

Nick, I am glad that you posted the information, it doesn't mean much to me other then relative sizing, but any information is better then no information. The one thing that I feel was missed was spray angles, as this has a big impact on injector performance. Unless of course all of the above injectors use the same spray angle.

To finalize what has become a bit of a novel, I don't run either of these vendor's injectors. I am just sick of hearing how aftermarket truck injectors are some how inferior to aftermarket TDI injectors.

Click to expand...

When I first read this, there were several things I had questions about, but I let them pass. Now that it has be brought up again I have a few questions.

#1. Don't giant parts just cost more because they are giant parts?
#2. Don't custom racing parts cost more because they are custom and often make of exotic materials?
#3. Wouldn't the Volkswagon engineers have built their injectors on the best technology at the time, which would have included everything before them?
#4. Please correct me here if I am wrong, but everything in these engines is not scalable, the GIANT engines they run in ocean liners vs 6L truck vs 1.9L cars while similar do have significant engineering differences?
#5. $2000 transmission?
#6. Is it really surprising that people in a TDIclub forum are enamored of the technology behind their vehicles?
#7. Where are the threads claiming that "aftermarket truck injectors are some how inferior to aftermarket TDI injectors" ? Kinda like comparing pears and apples (oranges would have been toooo different)

dvst8r said:

The only thing I want to add, is that I think it is funny that some how truck or tractor nozzles are crude, and that people don't have $400K to spend on a machine, I personally know several SMALL business owners that spend that kinda money every year just to go racing, let alone, on something that makes them money.

Upgraded injectors for direct injection diesel trucks have been produced since the early 90's The first VW TDI available wasn't till the late 90's, so with out taking into account tractors, that is nearly a decade more R&D time. Unlike the TDI market place where there are 3 maybe 4 injector manufacturer's there are at least a dozen aftermarket injector manufacturer's in the truck and tractor world. You think that after nearly 3 decades of competition that some how there technology isn't as good as TDI injector technology?

TDI's are small money, TDI injectors are small money, TDI R&D is small money. I have held in my hands a billet injection pump for a competition tractor that worth the same $$$ as a new TDI. It was in the pits for a spare. In the TDI aftermarket people balk at spending $2000, in the truck world that doesn't even get you a transmission.

To me the most ironic part of all of this is; the highest HP vw tdi in north america runs a set of custom edm'd cummins nozzles in machined TDI bodies, from neither of these vendors. Oh and just because you don't know about it doesn't mean its not out there.

Nick, I am glad that you posted the information, it doesn't mean much to me other then relative sizing, but any information is better then no information. The one thing that I feel was missed was spray angles, as this has a big impact on injector performance. Unless of course all of the above injectors use the same spray angle.

To finalize what has become a bit of a novel, I don't run either of these vendor's injectors. I am just sick of hearing how aftermarket truck injectors are some how inferior to aftermarket TDI injectors.

Click to expand...

2grand for a transmission? you bet, billet torque converters can cost 1/2 by themselves. many, many cummins, dmax, and pwrstroke guys are pushing 900+ ft/lbs and 600+hp on the street, and much more then on the pulling track. Heck alot of trucks are very capable street vehicles with 1000ft/lbs, 700hp and will get 25mpg towing my tdi to the track where the truck will rip an 11sec qtr mile.
but big parts cost BIG $$$

5) $2000 doesn't get you much more then a good torque converter. A full built billet setup will run $7000 - $10000. Want to get serious and step up to a bruno/lenco setup you start at $15,000 and go up.

1) To a small point parts cost more when there is more material. However production volume plays a far bigger role. For example; the case of the cummins 5.9, it is kind of like the SBC of the diesel world, it is found in everything imaginable, forklifts, boats, trucks, tractors, gensets, pumps, drills, ect... They are produced on a scale unlike almost any other engine. Parts for it compared to similar products are quite inexpensive.

2) Not sure what the cost of custom parts has to do with this, but yes, typically they are low production so costs are higher.

4) 1 Ton and smaller truck engines, share far more in common with a TDI then they do with an ocean liner. To the point that with some machining you are able to run cummins nozzles in TDI bodies.

3) We are not talking about VW oem injectors, which are bosch units, and are the best available (albeit in a limited size range), we are talking about modified units and the technology that is used to modify them.

6) Yes and No.

7) I don't have the time in my day to find past threads, I assure you it has, but don't take my word for it, there is a search button. That and it was compared in this thread.

I think that covers it?

I have just a couple of questions:
1) Can you explain a bit more the way nozzles were tested?
2) When did you buy Bosio boxes?

Oh, Mr. G. Bosio himself....welcome to TDIclub*g*

Personally I find this thread enlightening. IMO it shows that:

1. Everyone is quite reluctant to provide actual figures and parameters, along with testing methodolgy. If they provide one, they withold on the other

2. There are so many ways to screw a set-up (nozzles, injectors, combustion chamber, fuelling, pump, fuel quality) that unless there is a very methodical and open set of practices and procedures, it will be hard - if not impossible for the enthusiast to acheive levels comparable to OEM quality in an upgraded engine.

I was reading on the "nozzle wars" here and could not help but wonder - how would one make a "good" decision with so scarce information? Sure everyone will recommend a product or another. Based on what?

Personally, I think that for me the best option would be to go with Bosch. I believe there is consensus that Bosch delivers a quality product if the aim is to stay close to spec.

I also learned one thing - as good a job as DBW did, he clearly stated that HE - thus not a mere user like me - is missing flow characteristics and/or quantitative/qualitative parameters for non-OEM nozzles. And again, DBW confirmed that Bosch does provide reference nozzles, and is the only one doing so.

stefan_b said:

Personally, I think that for me the best option would be to go with Bosch. I believe there is consensus that Bosch delivers a quality product if the aim is to stay close to spec.

I also learned one thing - as good a job as DBW did, he clearly stated that HE - thus not a mere user like me - is missing flow characteristics and/or quantitative/qualitative parameters for non-OEM nozzles. And again, DBW confirmed that Bosch does provide reference nozzles, and is the only one doing so.

Click to expand...

Not the only one. Note what he said:
"Sorry that you are having problems with the supplier of your parts, get your money back and purchase nozzles from a known quality supplier like Bosch or Bosio.

If you want Factory Bosch or Bosio I will be happy to work out something with you to make sure they are setup properly. I have new Bosch nozzles in stock and will have a new selection of Bosio in next week fresh from Italy. I want your car to run properly but you will have to realize that quality nozzles start at $240.00 per set on up to $357.00 per set."

He is not saying that Bosch is better than Bosio -- he is saying that genuine nozzles from either manufacturer are the way to go. And to avoid cheap bogus nozzles from eBay vendors.

I have to tell you guys that flow testing nozzles with 50 PSI of shop air using a cheesy litres/liters per minute gage is a joke. While air is a fluid it reacts nothing like ISO test oil at 100 bar and up when flowing through a Diesel nozzle.

At a minimum, you need temperature controlled ISO test oil at 100 bar. Some use Shell. Some use other brands, but if it meets ISO 4113 specs it should be fine. We use Viscor. Hundreds of gallons a year.

I have a little knowledge in this subject.

Hey Don M's come back to the party. What's you newest prediction this year Don? Sorry we are all so "cheesy" as you put it but you know us common folk don't get to work in the presence of true royalty like you.

Sorry if i sound a little harsh but i enjoyed not having to read your self-proclaimed diatribe here. Here's my favorite TDIclub quotes from you:


dated 10/27/04:

I think I can cover all the power levels with one nozzle. Maybe two. Even with less smoke, we can make the HP/TQ.

Click to expand...

dated 10/28/04:

I dont currently sell any TDI products. Im working on TDI nozzles as of two weeks ago! LOL Getting my feet wet, so to speak. Im pretty much fresh out of the oven, but not half baked.

Im in Dallas. I use dealers to sell products for me now. I dont direct sell anything to the public. Its all Dodge Cummins, Ford Navistar, and Duramax Izuzu injectors only. A few hardcore hard parts ( camshafts, injection pumps, etc ) We dont have a store front. Its a manufacturing and distributing operation only.

I want in on the TDI market. Its not large and the money is certainly not there, but I need a new challenge. The injectors we have for the Cummins have really made postive changes to the entire market. Hopefully we can apply it to the TDI and the PD

Don~

Click to expand...

F1Diesel said:

I have to tell you guys that flow testing nozzles with 50 PSI of shop air using a cheesy litres/liters per minute gage is a joke. While air is a fluid it reacts nothing like ISO test oil at 100 bar and up when flowing through a Diesel nozzle.

At a minimum, you need temperature controlled ISO test oil at 100 bar. Some use Shell. Some use other brands, but if it meets ISO 4113 specs it should be fine. We use Viscor. Hundreds of gallons a year.

I have a little knowledge in this subject.

Click to expand...

hi there
anyone have tested dss ultime 2 0,280um ? are they 5 hole nozzles? are they stronger than bosio r520 5 holes 0,262um? i think they are

any dyno comparision ??

best regards

To Majesty78: thanks for your welcome, I appreciate it and sorry for my delay in replying.

To Stefan B : I think everybody buys what he wants with his personal money. It's true it's not easy to get right infos on the different products, like nozzles, that you can find on the market: but you might have some ideas that can make you reflect. Example: how long is the producer on the market, or how long is producing this stuff. You can buy parts from somebody that can give you suggestions choosing one brand or another one. Bosch develop parts strictly in cooperation with the engine producers and that's the reason why they are the reference. What we make, after all, is a copy and the our most important think is to make a good copy! It means that we can measure in deep nozzle flows, holes, roughness of surfaces, and all that caractheristic that lead us to built up a good part, at least this is what we think. And the deeper you "measure", the better results you will have. Then there is another step in which if we see there is a chance to get a better result in some operations, as example like in produtions process, sure we follow it. But this is related to the philosophy of each not OEM producer and sometimes this makes the difference between aftermarket products.


To TornadoRed: thanks for your consideration!

To Ndamico: please, I made a couple of questions and I would like your reply, if it's possible. And I have another one: I would like to understand why you don't like PP 764 with 7 holes.

Thanks to all of you

gbosio said:

To Ndamico: please, I made a couple of questions and I would like your reply, if it's possible. And I have another one: I would like to understand why you don't like PP 764 with 7 holes.

Thanks to all of you

Click to expand...

I don't speak for Ndamico, but the issue with the 7 hole R520 (PP764 too?) is the uneven hole spacing. I have heard the 7 hole PP764 have the same odd spacing as the 7 Hole R520. Why is this done? The pattern looks like it is a 5 hole nozzle with 2 holes added in between some holes.

Could you manufacture one with even holes instead?

Robnitro, it's true that the holes on the tip of the 7 holes PP 764 and 2 Race 520 doesn't have much space but we must make a step forward in order to understand why.
Imagine to put yourself on the surface of the piston when there is the injection of the fuel: you will see a cone. It's possible to calculate the geometry of the cone through the 5 main lines , if the nozzle has 5 holes, which are the directions of the holes generating the cone. There is another thing common to all TDI nozzles and in general to all nozzles which axis is not parallel to the axis of the piston: the distribution of holes in roundness is not unifirm. I mean that it's not 360 degrees devided by 5 but it consider also the different angle of each hole referred to the axis of the nozzle, and this angle effect the flow of each hole.
Keeping in mind this situation, I recalculated the 7 holes in order to re-create the same spray cone. I haven't put 2 more holes in the middle of somewhere but all has been re-calculated and generated. I have the machine so it's not a problem.
If you want, do a simple test. If you have the pump for the pop test, take a PP 764, remove the needle and the part inside the holder which might fall with the absence of the needle. Install the nozzle in the holder, connect the holder to the pop test. Take a plastic bottle, cut it in the middle, position the tip of the nozzle inside and make the pop test: you will see 5 lines which touch the bottle in 5 points. Connect the points with a line: you will draw a circle approx. Remove the 5 holes and install the 7 holes. Attention only to fix the holder in the same way otherwise you will loose all the reference point. Make the pop test and you will see that the lines are on the same alignement of the drawn circle and the distribution of the holes will be nice, in spite of the odd space that you see.
Give me some info!
Besides, as far as I know, Kerma guys never had a problem of breaking the tip of the nozzle: you can ask to Charlie or Paul. And also here in Europe I never had any kind of this problem or engine that breaks beacuse of a wrong spray pattern. Otherwise I would have stopped their production! It's easy!
Hope it's clear!

Mr. Bosio, I understand what you're saying about the hole geometry, but I disagree with some things. The spray cone you refer to definitely does not end up dispersing the fuel evenly. The flame patterns on this piston clearly indicate it.



In this motor, the angle of the holes was different between the injectors. In that piston pictured above, you can clearly see the flame marks on top of the piston where they shouldn't be. On the other 3 pistons, the flame marks are inside the bowl where they should be.

These were 7 hole race injectors installed and pop tested by a very reputable individual with only 5k miles on them when the motor was torn down.

Whitbread said:

Mr. Bosio, I understand what you're saying about the hole geometry, but I disagree with some things. The spray cone you refer to definitely does not end up dispersing the fuel evenly. The flame patters on this piston clearly indicate it.

In this motor, the angle of the holes was different between the injectors. In that piston pictured above, you can clearly see the flame marks on top of the piston where they shouldn't be. On the other 3 pistons, the flame marks are inside the bowl where they should be.

These were 7 hole race injectors installed and pop tested by a very reputable individual with only 5k miles on them when the motor was torn down.

Click to expand...

Yep. That piston looks familiar...pretty sad to have your cylinder head off for porting and discover a cracked piston due to this "wonderful" 7 hole geometry.

Are these even proven in the truck world?

I've been running 2R520s since early November and I have 18 fillups. I guess I'm averaging 600ish miles/tank and around 41mpg. I have considered changing to see what all the hubub is about with other nozzles. I even spoke with Nick to see about changing. The more I think about it, the more I'm inclined to keep running these. The smoke isn't bad since my last remap, and my mileage is good, all things considered. I also have the luxury of having 2 spare engines in my build room.

I do keep an eye on my EGTs and don't lay into the throttle until around 2k rpm.

Sorry for the hijack, Nick.

From my european experience they are just utter crap. We gained over 30hp and reduced the smoke with DSS ultime2 after a remap. A map made for 7holes and some smoke was totally clear with the ultime and the power was noticably better.

They were actually tested against old race and ulitme1 in a dyno with out unstraping the car and they had the worst power.

Whitbread said:

Mr. Bosio, I understand what you're saying about the hole geometry, but I disagree with some things. The spray cone you refer to definitely does not end up dispersing the fuel evenly. The flame patters on this piston clearly indicate it.

In this motor, the angle of the holes was different between the injectors. In that piston pictured above, you can clearly see the flame marks on top of the piston where they shouldn't be. On the other 3 pistons, the flame marks are inside the bowl where they should be.

Click to expand...

I do agree that fuel is not distributed evenly across that combustion bowl and I think that has to be the main problem with Bosio 7 hole design. I'm sure that seven hole strategy is better than five hole, but holes need to be more evenly distributed. Like Hatemi said, enough comparing test have been already made to verify this (OK, I have to admit that we are just doing this as a hobby with no qualifying education what so ever...)

Here's 2.5TDI with R520(7-hole) compared to DSS ultime2, no other modifications. Gain of 100Nm through the whole turbo's operating area and much less smoke (visual observation, no AFR measurement).



On the second matter (flame marks on top of that piston), are you sure that it's due to different angle between injectors? I mean, have you got those nozzles tested somewhere to verify this? I would suspect different "actual SOI" between cylinders to be reason for this.

shadowmaker said:

On the second matter (flame marks on top of that piston), are you sure that it's due to different angle between injectors? I mean, have you got those nozzles tested somewhere to verify this? I would suspect different "actual SOI" between cylinders to be reason for this.

Click to expand...

The first and second stage pop pressures were set by one of the professionals here who only does VW injectors. There was also less than 5K miles on that set of injectors. What else would make the flame patterns so different? 3 pistons were identical, 1 was an oddball. I checked injector protrusion on the bottom side of the head and all the injectors were even. One of the rods in the motor was compressed by ~1mm but it wasn't the cylinder that piston came out of.

I've seen the same thing happen in big rig motors where I've installed non bosch/denso/siemens/delphi reman injectors (against my recommendation). A couple weeks or months later, I usually end up putting a piston and liner in that cylinder. The flame patterns are always way off from what they should be on the melted piston. I had a local pump shop inspect one of these no name remans and they said the hole angles were off.

I'm seeing the same stuff here, albeit on a smaller scale.

Whitbread said:

The first and second stage pop pressures were set by one of the professionals here who only does VW injectors. There was also less than 5K miles on that set of injectors. What else would make the flame patterns so different? 3 pistons were identical, 1 was an oddball. I checked injector protrusion on the bottom side of the head and all the injectors were even. One of the rods in the motor was compressed by ~1mm but it wasn't the cylinder that piston came out of.

Click to expand...

I have seen this so many times before (only one piston has flame marks on top of it, even on Bosch nozzles). I just don't know why. I suspect nozzle manufactures must have strict tolerances regarding spray angle due to tooling methods? Mr. Bosio?

I've drawn up a crude picture of stock 5 hole, 7 Hole R520, and the evenly spaced 7 hole configuation. I based it on photos seen of spray patterns and of nozzle holes, so it is not 100% accurate, but close enough to illustrate the issues being brought up.

You can see how in the 7 hole nozzle, the holes are clumped on one side, unevenly- by the "center line" through 2 holes and the center of the nozzle.
The stock 5 hole and the ideal 7 hole configurations don't have a drastic imbalance of holes to sides as the 2R520's do.

Mr. Bosio, why wouldn't the geometric septagon pattern be better than an unevenly spaced pattern??? The stock nozzle has 72 degrees between holes, the septagon pattern has 51.4 degrees between holes, yet your design seems to have 45 degrees between holes (top half) and 60 degrees between holes on the bottom half. If the uneven hole pattern is ideal, why is the stock 5 hole an even hole pattern (evenly 5 sided)?

If you look closely at a standard 5 hole nozzle on a pop tester - the flow distribution is not symmetric even though the holes are spaced symmetrically.

Since the injector is not located centrally in the bore this seems to make sense so it does not wash the near side of the cylinder wall. This is all assuming that there's injection events outside of the piston bowl - which looking at the various piston pictures and the ones I've seen personally - there appears to be.

The "bottom" two holes on the 5 hole design are on that side for a reason I bet. Not to mention the fact that those two holes seem to flow less than the other 3 holes.

The practical evidence seems to show that there is an issue with the 7 hole bosio's for one reason or another. Maybe with 7 holes the closer orifices end up having the spray patterns merging together which would cause all sorts of problems with the droplets merging together and not burning completely?

I clearly see 4 "jet" locations on the top of the piston in Whitbread's picture a few posts up The "top" part of the piston does not show this same pattern with 3 more "jet" marks.

I'm just saying that of the 8 nozzles that I've played with on the pop tester (4 Bosio and 4 OEM Bosch) they've all shown this "imbalance" and I don't think that this is inherently the problem with the 7 hole Bosio's.

Sorry Nick - I guess this is off topic of your thread

robnitro said:

I've drawn up a crude picture of stock 5 hole, 7 Hole R520, and the evenly spaced 7 hole configuation. I based it on photos seen of spray patterns and of nozzle holes, so it is not 100% accurate, but close enough to illustrate the issues being brought up.

You can see how in the 7 hole nozzle, the holes are clumped on one side, unevenly- by the "center line" through 2 holes and the center of the nozzle.
The stock 5 hole and the ideal 7 hole configurations don't have a drastic imbalance of holes to sides as the 2R520's do.

Mr. Bosio, why wouldn't the geometric septagon pattern be better than an unevenly spaced pattern??? The stock nozzle has 72 degrees between holes, the septagon pattern has 51.4 degrees between holes, yet your design seems to have 45 degrees between holes (top half) and 60 degrees between holes on the bottom half. If the uneven hole pattern is ideal, why is the stock 5 hole an even hole pattern (evenly 5 sided)?

Click to expand...

This is how I see it:



2R520 is just a R520 with two additional holes between those three upper ones and it doesn't have burn marks in the 9 o´clock and 3 o´clock position (looking from the pictures those are more like 10 o´clock and 2 o´clock position, just like in R520)

Ideal 7 hole shouldn't be a septagon as our piston is asymmetric and its thinnest at the lower part (6 o´clock in the picture). Heat accumulation should be avoided there and thus either smaller lower holes and septagon or longer gaps between holes at the lower part (my drawning). Bosio 2R520 takes this to the extreme and has too much heat accumulation on the upper, beefier side of the piston (12 o´clock in the picture).

Sorry about my drawning skills.

Sorry for the delay in replying to all of you.
Whitbread, please I need some more info. Do the 4 pistons belong to the same engine or not? Or does the first photo show a piston damaged buy a 7 holes nozzle and the second one 3 pistons as they should be? If the 4 pistons belong to the same engine, can you tell me if in every cilinder there was a 7 holes installed and which one? Which is this type of engine and which are the stock nozzles? Eventually can you send them to me to analize?
Shadowmaker, we have instruments that let us measure an angle like 64,72°: it means we cut 1 degree in 100 parts. During the set up of the machine, we have drawings that increase the tip of one nozzle 50 time so we see angles and positions. At the end we have always a master ( Bosch original) for fixing the right angles and we have secial fixtures through which it's possible to check an error of 0,15°. We don't have any problem of repetibility of our Edm machine: we check the parts during the production so it's very strange to me that 3 nozzles has teh right directons and one is totally out. But you never know...
Robnitro, the spary pattern of stock P 520 ( the same works for P 357 or 764) is not a perfect pentagon. I don't know how to post a drawing so I try to explain it based on yours. Consider the point at 12 o'clock as hole n° 1 : it's angle is approx 50° referred to the axis of the nozzle; then going agains clock direction, hole n° 2 after approx 79 degrees ( watching from the head of the nozzle, not from the bottom) with 68° angle; hole 3 after 65 degrees with 95° angle; hole 4 after 74° and 95°; hole 5 after 66° with 68 degrees. As you see it's not perfect and this is due to the fact that the angle of the holder has approx 23° inclination referred to the axis of the piston ( these degrees are not 100% exact but significant). The target is to have a good distribution of the fuel in the combustion chamber so they must take in consideration the 23° of inclination and the fact that you will have higher flow from hole 1 ( due to the 50°) rather then hole 3 and 4 due to 95°. For the fuel is more difficult to make a 95° degrees turn rather than a 50°. And that's why in the 7 holes you have 4 holes more close that the other 3. If the axis of the nozzle would have been on the same line of the one of the piston, the septagon with 51,4° angle would have worked. As reference, you can check the 124 P 1309: I think it's fro Dodge or Cummins common rail: 5 holes with 72°. But the holder is stright in teh center of the head.

so you confirm that you have made the so called 2R520 7hole?

I understand what you say with the angle and the inclined nozzle, but please explain me how you ever can sell a nozzle as top of the bill with such an uneven fuel distribution in the bowl?

I'm not a nozzle engineer, but as many others I tested these nozzles and the only conclusion we could make was that they suck ass

I have a set which I ran about half a tank of fuel, if you want them to see if you made them I'll be happy to ship them to you, or maybe if you want to swap them for something with even bowl loading that are equivalent size as DSS ultime2

gbosio said:

Whitbread, please I need some more info. Do the 4 pistons belong to the same engine or not? Or does the first photo show a piston damaged buy a 7 holes nozzle and the second one 3 pistons as they should be? If the 4 pistons belong to the same engine, can you tell me if in every cilinder there was a 7 holes installed and which one? Which is this type of engine and which are the stock nozzles? Eventually can you send them to me to analize?

Click to expand...

All 4 pistons belonged to the same engine. All 4 injectors were the 7 hole R520's with about 5k miles on the injectors. The cleaned up piston I showed has a crack in it at the 3 o'clock position and you can clearly see 3 clumped heat marks at 11,12, and 1 with the others at 2:30, 5, 7, and 9:30. The engine was an ALH. The other 3 pistons had the heat marks in the bowl of the piston where they should be. Still unevenly spaced, but not on the top of the piston. Did you want to examine the damaged piston, the nozzles, or both?