Is there a difference between N/A injector nozzles and Turbo nozzles? - page 2 - IDI Engine - VWDiesel.net The IDI, TDI, and mTDI source.

• #15 by ORCoaster on 16 Jan, 2013 19:08
• Scrounger   If you are thinking the 20 bar difference is only 10% increase then check this out.
  
  155 bar = 2 248.08493 pounds per square inch
  135 bar = 1 958.00946 pounds per square inch
  
  20 bar but 290 psi.  290/ 1958 = .1481 or roughly 15% of the base value. 
  
  I would have to guess a bit more work needs to happen to get that increase.  How much HP?  I can't tell you that, I have no way to calc it. 
  
  
• #16 by theman53 on 16 Jan, 2013 19:15
• The GTD nozzles are different. Giles told me that they are not that much different in function, but they cost about 4x as much per nozzle. I have never seen the GTD nozzles, but they are the ones that came in the GTD cars. They had them in Europe I believe and they were intercooled and had more HP than what we got in the US in the TD cars. IIRC the GTD may have had a water cooled turbo, but that doesn't affect the nozzle discussion.
• #17 by RustyCaddy on 16 Jan, 2013 19:39
• If your interested in GTD nozzles one place you can get them is at Greaseworks (google).  They are made by Bozio and supposed to be pretty good...Justin could probably help with GTD questions.
  
   
  
  Some folks swear by Monarks for Mercedes diesels; i run Elsbetts for Mercedes (for vegetable oil) and they have been a big improvement over Indian Bosch nozzles when running 50% diesel too.  They are troughed, like Monarks
  
• #18 by scrounger on 16 Jan, 2013 19:48
• So if 135 bar nozzles give better mileage than 155 why not go down further. Surely 100 bar would give less pumping loss. My point is why would an engineering team choose the 'wrong' pop off pressure.
  
  I have always used 14.7 psi as standard pressure (1BAR). The 'new think' is going with 14.5. Not sure why std units are not used.
  
  I wrote to the Mercedes source who I was told was the distributer for monach and they told me that they couldn't help me with tuning a set of injectors for my vw.
• #19 by RustyCaddy on 16 Jan, 2013 20:23
• Quote from: scrounger on 16 Jan, 2013 19:48

  I wrote to the Mercedes source who I was told was the distributer for monach and they told me that they couldn't help me with tuning a set of injectors for my vw.
  

  
  That's weird...i bought a set of Monarks from Mercedessource.
  
  Here is the quote from my e-mail box one of the e-mails (i bought a set then, but then i got the Elsbetts instead...blah, blah):
  
  "Yup the 261 cross references directly to my monark nozzles for the mercedes from 1968-1985
  
  https://mercedessource.com/node/4757"
  
  They were referring to DNO SD261 which is different from the usual DNO SD293 Boschs i had before of course.
  
  Merc nozzles are set to 115 bar for non-turbo; for the Elsbetts, i set them at 135bar for the 1.6 NA since my pump is set at 1.00.  Don't know why that wouldn't work for Monarks but i am not the one on this forum to rely on about this.
  
  
  D'oh! now i see the link has them sold out right now
   
  
  
  
• #20 by scrounger on 16 Jan, 2013 20:32
•  Here is a copy of my msg and theirs (Mercedessource)
  HI Dave
  
  I am sorry we do not have any monark Nozzles for VW
  
  kaia
  
  
  On Jan 13, 2013, at 7:01 AM, [email protected] wrote:
  
  Dave sent a message using the contact form at http://mercedessource.com/contact. Can I get a set of 4 nozzles tuned to 155 bar for my 1986 1.6 Jetta TD? Thanks.
  
• #21 by RustyCaddy on 16 Jan, 2013 20:35
• this is the e-mail the above was a reply to:
  
  Kaia,
  
  The source i read for the info lists the Mercedes nozzle that would fit the VW as:
  
   DNO SD261
  
  So i think that i am looking for the Monark nozzle that replaces that Bosch part.
  
  The usual VW nozzle part number(s):
  
  DNO SD273 and also listed as DNO SD293
  
  
  
  
• #22 by libbydiesel on 16 Jan, 2013 20:51
• I have tried 150 bar and 160 bar injectors with new nozzles in the same engine.  I always set the timing using a diesel pulse adapter and strobe to 12° BTDC and so the actual start of injection is the same.  The 160 bar got dramatically worse mileage (approx 15%) with similar driving.  I have also used the 135 bar nozzles, but not as scientifically.  I believe there is a point of diminishing returns with dropping the injection pressure where the atomization gets bad enough to waste more fuel from the incomplete burn than is saved from the pumping losses.  I also believe that the trend to higher break pressures is not for performance or fuel economy but rather for emissions.  I have always wanted to take the time/money and make up several sets of injectors in order to find the peak for these engines but have always had higher priorities. 
• #23 by fatmobile on 16 Jan, 2013 21:29
•  There was someone on here long ago that did some testing using the long drive to work.
   And found 125 to be the most efficient.
   With efficiency dropping off below that.
  
   I couldn't begin to find the post but it stuck in my mind.
  
  Yeah I know, it's not scientific proof so believe at your own risk.
  
   Not sure if that was TD or not.
• #24 by TylerDurden on 17 Jan, 2013 13:22
• Quote from: libbydiesel on 16 Jan, 2013 20:51

  I also believe that the trend to higher break pressures is not for performance or fuel economy but rather for emissions. 
  

  
  Seems to be.
  
  Some mention of that in this overview:
  http://files.nequam.se/greenCarLecture.pdf
  
  More on combustion & modeling:
  https://www.princeton.edu/cefrc/Files/2012%20Lecture%20Notes/Reitz/Princeton-CEFRC7.pdf
  http://www1.eere.energy.gov/vehiclesandfuels/pdfs/merit_review_2012/adv_combustion/ace001_musculus_2012_o.pdf
  http://www.transportation.anl.gov/pdfs/EE/715.PDF
  
  
  
• #25 by Blownoiler on 26 Jan, 2013 15:04
• Nice links Tyler, but a bit complex, and mostly related to direct injection engines! Turbofan, what exactly happened to your last engine? there are a few rules to follow for better engine life!
• #26 by Turbofan on 29 Jan, 2013 19:13
• Honestly, nothing significant happened. Over the summer I ripped the head off it because I wanted to fix the oil leaking from the head gasket, as my gf was less than thrilled about the oil mark in the driveway. I too wanted to fix the oil leak, as I deal with enough leaky motors at work (where I wrench on Land Rovers). While the head was off, I cleaned the piston crowns by adding a bit of diesel to each of the cylinders. I found 2 cylinders (1 and 3 I think), wouldn't hold fluid as the others did, so I pulled the pistons, ball honed the cylinders and re-ringed it. It seemed fine, and had good power (I could more or less keep up with my gf's 2010 tdi on the highway) and was getting decent mileage, but something was still off.
  
  http://www.vwdiesel.net/forum/index.php?topic=31754.msg289801#msg289801
  
  Basically, it would idle fine when cold and I first started it, but it would smoke like hell.If I put a load on it, it would miss for the first 15-20 seconds. I should mention at the same time I did the HG, I had the injectors professionally rebuilt, with Bosch nozzles. I decided to go over the basics, and bought a compression gauge from GSI (http://www.gsiindustries.com/cgi-bin/Order/data.pl?id=6610) (they will sub out the gm 6.5 adapter for the tdi adapter for no charge btw!) and found that compression was not as even as it should be, and ranged in the 300's with one cylinder at 400. I think the Bentley suggested the wear limit was 400, so I was effectively below that on all cylinders. So as I was on break from school, I pulled the Golf in once again and pulled it apart, this time having the machine shop check the bores (which ended up being perfect). They cleaned it, honed it, and once again I bought some new rings and put it back together. I started this post as I finally bought a TD IP from another member, and was wondering if it would be worth it to have the correct TD nozzles on my injectors and have them adjusted to the correct break pressure. I'm hoping for the ability to get better than 42 mpg. I was running a AAZ camplate in my IP, which I will swap over to my TD pump, and I was gov modded, BUT I also new how to drive with love and respect. I suspect my NA pump was just pumping too much fuel into my motor (though my EGT's remained in the safe zone).
  
  
  So here's a new non-related question. Have any of you ever run into a crack gear that had a small amount of play on the crankshaft? Neither the key on the gear nor the crank look worn at all. Interestingly, whenever I played with my timing, I couldn't quite get the timing pin into my IP, and I'm wondering if the gear was off by a little bit. I should be able to find out the conclusion to my exciting story on Friday, when I work again and put it back together.
• #27 by 92EcoDiesel Jetta on 30 Jan, 2013 07:01
• Quote from: Turbofan on 29 Jan, 2013 19:13

  ......................
  
  So here's a new non-related question. Have any of you ever run into a crack gear that had a small amount of play on the crankshaft? Neither the key on the gear nor the crank look worn at all. Interestingly, whenever I played with my timing, I couldn't quite get the timing pin into my IP, and I'm wondering if the gear was off by a little bit. I should be able to find out the conclusion to my exciting story on Friday, when I work again and put it back together.
  

  
  There should be no play between crankshaft and crank sprocket. Did you remove the cam sprocket when you set the timing? You have to do that in order to get the timing exact and get the timing pin aligned in the IP sprocket.
• #28 by tyb525 on 30 Jan, 2013 10:05
• Quote from: scrounger on 16 Jan, 2013 19:48

  So if 135 bar nozzles give better mileage than 155 why not go down further. Surely 100 bar would give less pumping loss. My point is why would an engineering team choose the 'wrong' pop off pressure...
  

  
  Lower breaking pressure gives better mileage to a point, just like thinner oil gives you better mileage, to a point, and that point is when you cause excessive wear and/or seize your engine by running too thin oil..
  
  Like others have mentioned, higher breaking pressures are mostly for reduced emissions. Also, on a TD, the cylinder pressures are higher under boost, so injectors that spray with more pressure might be beneficial.
• #29 by Blownoiler on 30 Jan, 2013 17:19
• I did a hone/re-ring on an idi some years ago, the ring end gap was right at the large end of the manufacturers tolerance, (60 thou), the engine took a good 10,000 kilometres to break in, and then still had a small amount of blowby (I got a bit carried away with the hone). Starting that engine from cold didn't result in any missing until I retarded the camshaft timing around 6 degrees (for better top end breathing), then on the 0 degrees c. mornings it didn't quite have enough cylinder pressure/heat to light the charge for the first 10 to 20 seconds on 1 or 2 cylinders as retarding the camshaft means that the intake valve closes a bit later on the comp. stroke, allowing some reversion.  Any other missing on cold startups has always been because of air finding it's way into the injection pump on my vehicles. Surely your new injectors have had their pop pressures set correctly, unless you got them done on a friday afternoon when everyone is in a rush to get to the pub, or monday morning when most folk are still in recovery mode!!