When I was over there about 12 years ago we sourced about 2000 or 2500 gal for auxiliary engine use. LOL - I remember the tank truck driver saying the HS on the delivery receipt meant that it was "high speed" diesel. We knew it was short for high sulphur diesel at 2500 ppm (0.25%). The CATS handled it well though I wouldn't have wanted to run it in a car. Its nice to things improving over there. Last time I was there was in '05. Air quality was definitely up from earlier visits.
CR engine HPFP analysis
- Thread starter oilhammer
- Start date
The engine doesn't care how much sulfur is in the fuel (within reason), it's the chemical conversion post combustion of sulfur compounds that react with atmospheric moisture and create acidic rain. Less sulfur going in means less SOx coming out.
In the marine game burning IFO-180 or higher, once sulfur edged above 10,000 ppm (1%) exhaust valves began to show visible deposits also requiring more frequent turbine side washing in addition to normal compressor washing. Way beyond anything auto engines could handle. Its all a function of refinery input selection and existing refinery processes. Moving India up in quality no doubt required significant investment into the existing refinery supply chain. A cost we all pay for at the pump.
Last edited:
Roller Velocity
I've done some measurements that allow for a guestimate of follower captive roller velocity as a function of pump / engine RPM. The Cam Large OD is ~ 1.8484" Small OD is~ 1.4382" The captive roller OD is ~ 0.3939". The roller carrier ID is ~0.3954". This yeilds the following speed ratio's
Roller Max = 4.6918 x Cam RPM
Roller Min = 3.6511 x Cam RPM
These are based on assuming zero slippage between the cam and roller contact surfaces.
RPM's
Engine Roller Max Roller Min
4500 21,113 16,430
2000 9384 7302
600 2815 2191
With these kinds of roller RPM's it's easy to imagine damage to the coating on the ID of the roller carrier when there is enough metalic swarf in circulation to get wisked through in the film of lubricating diesel oil separating the roller from the carrier. The diametrical clearance between the roller and carrier measured out at ~ 0.0015".
HP piston diameter measured out at ~ 0.2562" with an estimated stroke of 0.2015" (based on cam radii). The piston area is ~0.051716 square inches. The normal force on the roller can be estimated based on the following HPFP pressures as follows:
CR Pressure (BAR) Roller Normal Force (Pounds Force)
1800 1350
1200 900
600 450
230 173
These numbers help to define the dynamic lubrication challenge present between the roller and its carrier under the variation of RPMs and CR loading forces present.
If I can capture the profile of the cam it will be possible to estimate thrust loadings transmitted to the follower at various angles. Beyond what happens at the roller, lubrication between the pump bore and cam follower and the torque transmitted between those surfaces is probably the initial source of wear material for this pump.
In thinking about these numbers a bit, there is are a lot of strong forces acting between tight clearances with minimal lubrication being present. No small order for any pump designer to fill. It's becoming easier and easier to understand why this pump is seems sensitive to low levels of fuel contamination.
I've done some measurements that allow for a guestimate of follower captive roller velocity as a function of pump / engine RPM. The Cam Large OD is ~ 1.8484" Small OD is~ 1.4382" The captive roller OD is ~ 0.3939". The roller carrier ID is ~0.3954". This yeilds the following speed ratio's
Roller Max = 4.6918 x Cam RPM
Roller Min = 3.6511 x Cam RPM
These are based on assuming zero slippage between the cam and roller contact surfaces.
RPM's
Engine Roller Max Roller Min
4500 21,113 16,430
2000 9384 7302
600 2815 2191
With these kinds of roller RPM's it's easy to imagine damage to the coating on the ID of the roller carrier when there is enough metalic swarf in circulation to get wisked through in the film of lubricating diesel oil separating the roller from the carrier. The diametrical clearance between the roller and carrier measured out at ~ 0.0015".
HP piston diameter measured out at ~ 0.2562" with an estimated stroke of 0.2015" (based on cam radii). The piston area is ~0.051716 square inches. The normal force on the roller can be estimated based on the following HPFP pressures as follows:
CR Pressure (BAR) Roller Normal Force (Pounds Force)
1800 1350
1200 900
600 450
230 173
These numbers help to define the dynamic lubrication challenge present between the roller and its carrier under the variation of RPMs and CR loading forces present.
If I can capture the profile of the cam it will be possible to estimate thrust loadings transmitted to the follower at various angles. Beyond what happens at the roller, lubrication between the pump bore and cam follower and the torque transmitted between those surfaces is probably the initial source of wear material for this pump.
In thinking about these numbers a bit, there is are a lot of strong forces acting between tight clearances with minimal lubrication being present. No small order for any pump designer to fill. It's becoming easier and easier to understand why this pump is seems sensitive to low levels of fuel contamination.
I was joking about fuel quality on the last page.
At least I should be assured that there would be no shortage of Golfs in salvage yards if things take a turn for the worst, because my US warrantee won't cover anything in Europe. With specsalot's measurements and various other data I may think of designing some steel replacement parts. Getting them made would be a completely different story. To be honest, I haven't really looked into this a whole lot, yet.
At least I should be assured that there would be no shortage of Golfs in salvage yards if things take a turn for the worst, because my US warrantee won't cover anything in Europe. With specsalot's measurements and various other data I may think of designing some steel replacement parts. Getting them made would be a completely different story. To be honest, I haven't really looked into this a whole lot, yet.
CedarPark68
Veteran Member
specs,
I'm still of the mind set that we begin to find replacements for these three parts.
I have a feeling we would never be able to source these individual pieces form Bosch directly ..... so anything... even exact replicas with no 'ehancements' would be better than nothing.
I'm gonna ask the local Bosch Diesel Injection technicians ( need to buy another jug of Stanadyne anyway ) regarding spare parts for this series.
koharatx - Your joke went right over my head which is hilarious 
The design improvement would be to sleeve the aluminum bore the follower rides in. Problem is there isn't a lot of room to open the bore up. The aluminum really seems way too soft for the follower.
The design improvement would be to sleeve the aluminum bore the follower rides in. Problem is there isn't a lot of room to open the bore up. The aluminum really seems way too soft for the follower.
Last edited:
I think Bosch will be forced to open this pump by selling replacement components. The model and SN of the 'failed' pump I have is:
P/N 0 445 010 508
Model: CR/CP4S1/RE5/20
Alt P/N: 03L 130 755 A
S/N 01 180108
BPT 0433 0003
The follower assembly is marked with the following P/N: 6007 9315
These # may help you with your inquiry at your local Bosch Shop. I haven't had a chance to query the one in my area (about an hours drive away)
Swapping the follower is a good strategy to extend pump life if you catch things early enough. I'll be surprised if 3rd party replacements aren't in the Euro supply chain for this assembly within the next couple years. This will likely become an OEM recommended PM if NHTSA blows this issue up big.
Last edited:
GraniteRooster
Veteran Member
The design of this pump is just off-the-charts silly. 21,000 rpm roller with half-circumferential contact on one side and the other point loading on the cam. Supporting 1350 lbs load stroking up to 9,000 strokes/minute, that's 150 strokes/sec!! Making 26k+ psi in aluminum bore with fatigue yield stress / safety limits near same?
Margin for error? Factor of safety? Common Sense? **Whiskey**Tango**Foxtrot**
Margin for error? Factor of safety? Common Sense? **Whiskey**Tango**Foxtrot**
Last edited:
emdeeaitch
Veteran Member
As of yet do we know what was done in the fourth version of the pump (the Nov 2010 and later) that VW thinks will make this OK? Has anyone here disassembled that version? Now that I own that version, I am dying to know.
When I get my in situ cleaning rig built, I'll let you know what I find inside based on parts I can get a look at. Right now my Golf only has about 5500 miles. After the 10k service, I want to have some things in place to begin to get intimate with my HPFP With a build date of Feb '11, I've probably got version 4 on mine. Which P/N is the latest version?
With a build date of Feb '11, I've probably got version 4 on mine. Which P/N is the latest version?
Last edited:
Yep, the first time I ran the numbers I figured I dropped a decimal point somewhere. These are some significant mechanical cyclical forces. The design is pretty ballsie and scary at the same time. It's very hard to think about boring out to sleeve the bore given the orientation of the thrust to the wall that holds the transfer port. Delphi avoided that flaw by orienting the transfer port 90 DEG away from the thrust axis. No doubt Bosch made the choices they did because they were designing the CP 4.2 twin cylinder units as well and needed to keep the design as compact as possible.
The fact that this pump runs as well as it does is a tribiological triumph. Ill bet the guy who cleaned up the Bosch development lab carted a lot of junk parts to the recycle bin. This pump is scary. But I'll bet any pump making 26k psig @ 4500 rpm would be anyway. Modification beyond just improving existing (O) PM's needs to be approached very carefully here. We are driving the bleeding edge of development that's for sure. One wrong step in the CR pressure control loop and it's probably game over for this pump in a short time.
Last edited:
emdeeaitch
Veteran Member
The part number is the same on all of them, so you have to go by the pump's build date right below that on the same sticker. Since the new Passat version is E, it is implied that ours are A,B,C, and D, but the letters B,C, and D don't appear on the actual sticker (as VW is not incrementing them), or anywhere else as far as I can tell... Yep, I would think with a Golf you would have the latest. Golf's seem to get same month build for both pump and car build date, whereas Jettas tend to get them 3 months apart. I'm assuming that is for the obvious Mexico vs. Germany shipping time difference between the two.When I get my in situ cleaning rig built, I'll let you know what I find inside based on parts I can get a look at. Right now my Golf only has about 5500 miles. After the 10k service, I want to have some things in place to begin to get intimate with my HPFP
Last edited:
GraniteRooster
Veteran Member
Where's the Beef?
No doubt this pump is in many ways marvelous engineering and at the bleeding edge of function and technology! But I am reminded of the old Wendy's commercial - "Where's the Beef?"
This pump is held together with hope Alloy steel correctly shaped with proper lubrication works much better
21krpm @ 1350 lbs, tiny little roller lubed by US-Spec diesel
And I agree mods need to be approached very carefully with respect to filters, etc.
No doubt this pump is in many ways marvelous engineering and at the bleeding edge of function and technology! But I am reminded of the old Wendy's commercial - "Where's the Beef?"
This pump is held together with hope
Alloy steel correctly shaped with proper lubrication works much better 21krpm @ 1350 lbs, tiny little roller lubed by US-Spec diesel
And I agree mods need to be approached very carefully with respect to filters, etc.
Last edited:
OilBurningBrit
Veteran Member
Those numbers are nothing short of amazing. I'm stunned that it works at all ...
That said, I've read through *most* of this thread and one thing is bugging me: I've seen no mention of trying to max out the number of miles per tank of diesel. Apologies if I missed a post ... it's a very long thread!
Getting, say, 700+miles on a tank must result in essentially no fuel left in the tank. What happens to the lubrication source for the (way, way delicate) HPFP at that time?
This *could* result in a cluster of failures immediately following a fill-up, I think, since the low fuel condition would have occurred immediately prior.
Disclaimers:
1. I don't know how many of the people experiencing failures are in the habit of running their tank essentially dry.
2. Running low on (or out of) fuel should not cause a catastrophic failure IMHO.
That said, I've read through *most* of this thread and one thing is bugging me: I've seen no mention of trying to max out the number of miles per tank of diesel. Apologies if I missed a post ... it's a very long thread!
Getting, say, 700+miles on a tank must result in essentially no fuel left in the tank. What happens to the lubrication source for the (way, way delicate) HPFP at that time?
This *could* result in a cluster of failures immediately following a fill-up, I think, since the low fuel condition would have occurred immediately prior.
Disclaimers:
1. I don't know how many of the people experiencing failures are in the habit of running their tank essentially dry.
2. Running low on (or out of) fuel should not cause a catastrophic failure IMHO.
emdeeaitch
Veteran Member
It's amazing that the spring return rate can support that. I have been trying to relate that to any other spring device that I use on a daily basis and couldn't. But we can safely say that it's faster than a hummingbird's wings but slower than a mosquito's.
Right - It makes sense to believe that the recirculated fuel plays an important role in pump cooling. While no one can run the tank dry without an engine shutdown due to low CR pressure at some point, it's more important to think about how a low tank level could affect the temperature and pressure of fuel supplied to the pump. The Bosch system monitors fuel supply temp to set injection duration (delivering the correct quantity of fuel). Recirc flow is based on a pressure differential set between the Aux fuel pump discharge and the overflow valve pressure setting. Nominally this should ~ 10 psid. If the supply pressure were to fall it could affect the quantity of fuel recirculated with out the Bosch system really seeing this situation.
This sets the stage for a thermal transient in the pump which affects lubrication at the critical interface between the roller and it's carrier. With no direct knowledge of the engine control system so long as engine demand was well down on the output curve.
I never run my tank below 1/4. I've also seen that fuel supply temp varies over a wide range during summer service. Running a tank way down for accurate mileage stats is a bad idea.
This idea has been brought up many times in this thread. I tend to sound like a broken record on this point. VW has significantly revised the MY2012 fuel system to reduce the complexity (and possibly the vulnerabilities) associated with the Golf, Jetta, JSW two pump supply to the HPFP. Implied in the narrative, if supply to the HPFP were to fall to 63 PSIG, recirc flow would begin to approach zero. Loss of convective cooling flow would have an impact in pump internal temps and lubrication.
This sets the stage for a thermal transient in the pump which affects lubrication at the critical interface between the roller and it's carrier. With no direct knowledge of the engine control system so long as engine demand was well down on the output curve.
I never run my tank below 1/4. I've also seen that fuel supply temp varies over a wide range during summer service. Running a tank way down for accurate mileage stats is a bad idea.
This idea has been brought up many times in this thread. I tend to sound like a broken record on this point. VW has significantly revised the MY2012 fuel system to reduce the complexity (and possibly the vulnerabilities) associated with the Golf, Jetta, JSW two pump supply to the HPFP. Implied in the narrative, if supply to the HPFP were to fall to 63 PSIG, recirc flow would begin to approach zero. Loss of convective cooling flow would have an impact in pump internal temps and lubrication.
Last edited:
emdeeaitch
Veteran Member
(EDITED) After looking back at a bunch of older posts in this thread and one other, I think MY2012 as used above refers to that in the Passat. Golf/Jetta still the same (I think). Specs, I know you know that, because you said as much several dozen posts ago. Just clarifying for anyone confused.
Last edited:
Natural Resonant Frequency of the follower assembly can be approximated by the square root of K (spring constant)/M (component mass). The spring fitted to this pump is so beefy that you can't turn it over by hand. One of these days I'm going to try to measure K & M and estimate the compressed length of the spring when the roller is on the base circle.
The idea of a 'float event' (mechanical resonance) could play into failure at some point in the process. But I personally think Bosch was able to solve this Engineering 101 question successfully.
Last edited:
The new fuel system in the 2012 Passat is significantly different from the 2012 Golf, Jetta, JSW.
Changes referenced in this thread for Passat:
1. A single transfer pump located in the fuel tank.
2. No fuel return from the fuel filter back to the tank.
3. HFPF is not compatible with GOlf, Jetta, JSW.
4. Injectors are solenoid operated, not piezo electric units.
5. Exhaust treatment system uses dilute urea (Add Blue) implying an SCR process in use. This may reduce the requirements for as much direct EGR to the engine intake tract.
It's funny the Delphi fuel system uses solenoid operated injectors (not piezos). It also features a low pressure return implying less dependency on return fuel flows for pump cooling / lubrication support.
So who knows, maybe Bosch has already cross licensed Delphi's HPFP design.
GraniteRooster
Veteran Member
I don't know the development history, but I note that Delphi has three common rail fuel management systems:
1) Direct Acting Diesel - piezo-injector based 2000 bar
2) Multec - solenoid based
3) Unit Pump Diesel
http://delphi.com/manufacturers/auto/powertrain/diesel/crfs/
They seem to refer to the Direct Acting as "most sophisticated", while the Multec is "best value", but they seem to have similar performance specs. I'd be interested to know which is the flagship product and why. I also note that the fuel pump for the DA system has a built in temperature sensor. No mention of that on the Multec (DPF6) pump, but I wonder....
1) Direct Acting Diesel - piezo-injector based 2000 bar
2) Multec - solenoid based
3) Unit Pump Diesel
http://delphi.com/manufacturers/auto/powertrain/diesel/crfs/
They seem to refer to the Direct Acting as "most sophisticated", while the Multec is "best value", but they seem to have similar performance specs. I'd be interested to know which is the flagship product and why. I also note that the fuel pump for the DA system has a built in temperature sensor. No mention of that on the Multec (DPF6) pump, but I wonder....
manual_tranny
Smyth Performance- Intern
I believe the move back to solenoid injectors is just a reflection of which technology is currently the most advanced. Back when they went from MK4-MK5 cars, solinoid injectors could only deliver fuel 3 times per injection event..
I'm not sure how many times the PD injectors can inject, but their design increased fuel pressure by putting the pump inline with the injectors.
Then came the Piezo injectors with common-rail pump, capable of 5 injection pulses per combustion event.
But, the solenoid injectors got jealous and said "Don't forget about us, we can do better!" ... and now the solenoid injectors are up to 6 injection pulses per combustion event.
If my understanding is correct, this multiple injections per event is more advantageous for reducing engine noise and increasing power, and is less important for increasing average efficiency.
We've come a long way from mechanical pumps and single injection events.
I'm not sure how many times the PD injectors can inject, but their design increased fuel pressure by putting the pump inline with the injectors.
Then came the Piezo injectors with common-rail pump, capable of 5 injection pulses per combustion event.
But, the solenoid injectors got jealous and said "Don't forget about us, we can do better!"
... and now the solenoid injectors are up to 6 injection pulses per combustion event.If my understanding is correct, this multiple injections per event is more advantageous for reducing engine noise and increasing power, and is less important for increasing average efficiency.
We've come a long way from mechanical pumps and single injection events.
Ski in NC
Top Post Dawg
We need to learn more about the passat cr system. There seem to be quite a few more differences than just the urea nox control. I wonder if some of the plumbing differences may also keep pump swarf out of the hpfp pump head and thus rail and injectors. Maybe they quietly did some fixes that are not advertised.
Anybody got some more details on the passat system?
Anybody got some more details on the passat system?
1TDI4Me
Well-known member
- Joined
- Aug 11, 2004
- Location
- Idaho Falls,Idaho
- TDI
- '01 Jetta (sold, but missed) '12 Jetta TDI 6sp Malone and Rawtech, '13 Golf DSG (SOLD!)
We've come a long way from mechanical pumps and single injection events.
Yes, like clear back ten years ago when my VW got over 50 mpg.
manual_tranny
Smyth Performance- Intern
Yeah, and 10 years ago when 90hp was an awesome amount of power to get from a 1.9 turbodiesel.
That's why I said the main progress point is in noise reduction and power gain. GoFaster has posted various places that a single injection event, (with the shortest possible injection duration) is the most efficient way to burn fuel.
That's why I said the main progress point is in noise reduction and power gain. GoFaster has posted various places that a single injection event, (with the shortest possible injection duration) is the most efficient way to burn fuel.
Last edited:
Environmental regulations, the lowering of compression ratio's in the name of satisfying emission requirements is probably the main reason for the drop in MPG. Manny makes good point's about power delivery and noise reduction. Also part of the game. Try finding some farfugnuven cruising in your Prius.
I haven't drilled into the VW 3 cyl "Polo" that is based on the Delphi DFP 6 with the solenoid injectors. My brother said its supposed to something like 67 MPG(?) Europeans have always paid more for fuel (even using currency adjusted pricing) and so have to value economy a bit more than US owners. We have wide open spaces here and do so love to "roll".
Bosch documentation claims their piezo injectors are at least 4x (IIRC) faster than traditional solenoid injectors. The write up on the Delphi DFP 6 with the multitech solenoid injectors is a bit mis-leading. They claim (IIRC) 6 injections per engine power cycle. This equates to 2 injection events per cylinder for a 3 cylinder engine in two crankshaft rotations (ie one power cycle). This is why I believe their HPFP runs at 2/3 crank shaft speed. Delphi's carefully worded prose makes it sound like the solenoid units are faster than piezo's but that does not make intuitive sense.
The challenge of any high speed CR pump design in todays fuel environment seems to be partially focused on eliminating the generation of metal swarf to begin with. The more I squint at the pump I have (better pictures will be posted when I get time to snap them), the more it seems to be clear that some of the initial wear does in fact reflect steel on steel (captive roller and pump cam shaft) due to fuel lubricity issues. The wear material I found in the relatively pristine pump I have is both ferrous and non-ferrous. Looking at the cam surface more closely there is some very fine scratching present. This type of wear is probably directly tied to lubricity.
As critical as we've all been of the Bosch design, they have done some amazing things on balance. Clearly we all wish they worked a little harder at it. I'm sure the Bosch folks are now wishing the same thing. How this all shakes out will be critical to both the owners of these vehicles and the folks who manufacture them.
My sense (more supposition I know) is that moving to Ad Blue probably lowers the need for the high levels of EGR and reduces the need to manage combustion events purely to sustain the back end systems to meet emission requirements. No one is likely going to put that genie back in the bottle as regards emission regulations until we start bumping up against "affordability issues" for our cars. The game is likely shifting to who can build the cheapest robust system to meet the upward shifting CARB NOx requirements.
I would bet that moving to Ad Blue probably simplifies EGR management requirements significantly. These changes should lower initial costs and lifetime maintenance expenses. The higher end components in the Golf, Jetta, and JSW systems seem all about improving atomization and controlling combustion in order to support the back end. The lowering of engine compression ratios delivers more available energy to the turbocharger increasing the turbo's ability to alter intake flows supporting the back end processes. This shift in energy balance probably also extends the performance envelope of the engine. The bet is that we all place a higher value on Power than MPG. Judging by the size of the "computer tuner" cottage industry, this looks like an accurate assessment - At least for the enthusiast owners who post here
Last edited:
maxedtdi
Veteran Member
Can someone clear up the model number issue.
I have a 2011 TDI
Fuel pump model # is 03L 130 755 A
Build date is 25/10/10
I don't see how some were stating there is a different letter (B, C, D) suffix attached to updated versions of the pump.
I have a 2011 TDI
Fuel pump model # is 03L 130 755 A
Build date is 25/10/10
I don't see how some were stating there is a different letter (B, C, D) suffix attached to updated versions of the pump.
emdeeaitch
Veteran Member
The B, C, and D are silent revisions, so VW sticks with the original "A" on the sticker. We are just inferring that the known silent revisions are referred to internally at VW/Bosch as B,C, and D due to the new Passat version having an E. The only way to know whether you have ABCD is by the build date of the pump, which fortunately is on the sticker. In the public portion of their discourse with the NHTSA, VW has disclosed the months in which the revisions were made. Counting the original unmodified version from early 2008, there are four versions, hence ABCD. The last revision was made in Nov 2010, so yours would be a third version, or C.
FWIW, I just corrected a post that I made yesterday to Specs that slightly confused the point.
maxedtdi
Veteran Member
How did folks get revision information ? And where can I find out more info on that.