Inside the HPFP

Jesse_Boyer · Oct 31, 2013

bhutchins said:
some more on the side topic of the 4.2 adaption.

development courtesy of 2micron

CP4.2 mounted on factory bracket with the spacer:

adding a port to the fuel rail

2004LB7 said:
wouldn't it be better to just use the shaft and front plate from the stock 4.1 HPFP so no adapter plate would be needed?

Is 2micron re-clocking the CP4.2? (doesn't look like it and based on the holes, the spacer serves only as a spacer.) Is it clocked like this

Instead of modifying the rail and adding a port for the second head, could it be possible to route the outputs of both CP4.2 heads to an off-the-shelf wye-block and run one line to the factory rail? Less machining and since a new line/connection is needed for the second head anyway, it might be lest costly.

JFettig · Oct 31, 2013

looks like the holes were perfectly clocked from the factory!

A single feed port to the rail might become the restriction, adding a second isn't a bad idea.

Paulinski · Oct 31, 2013

Wow....Very cool..

Keep us posted bhutchins

Jesse_Boyer · Oct 31, 2013

JFettig said:
looks like the holes were perfectly clocked from the factory!

A single feed port to the rail might become the restriction, adding a second isn't a bad idea.

I'm pretty surprised it bolts up as well as it does. Very cool indeed.

Regarding a restriction, the system's fuel pump valve will only allow enough fuel to maintain the pressure the rail which won't change as fuel demand isn't changing, no? Either way, getting the pump to fit and operate is the challenge. Plumbing the head(s) to the rail is a cake-walk in comparison.

bhutchins · Oct 31, 2013

Jesse_Boyer said:
Instead of modifying the rail and adding a port for the second head, could it be possible to route the outputs of both CP4.2 heads to an off-the-shelf wye-block and run one line to the factory rail? Less machining and since a new line/connection is needed for the second head anyway, it might be lest costly.

the vehicles that come with the CP4.2 (aka touareg 3.0 TDi) have two lines, one to each rail, and a balance tube between the two rails. one tee'd line might work, especially since the pressure pulses are at different timing, but working with 1600 Bar, (23,520 psi) is a lot more complicated than working with your typical parker or swagelok compression fitting

lines will be rated for at least 30,000 psi

Jesse_Boyer · Oct 31, 2013

JFettig said:
looks like the holes were perfectly clocked from the factory!

A single feed port to the rail might become the restriction, adding a second isn't a bad idea.

bhutchins said:
the vehicles that come with the CP4.2 (aka touareg 3.0 TDi) have two lines, one to each rail, and a balance tube between the two rails. one tee'd line might work, especially since the pressure pulses are at different timing, but working with 1600 Bar, (23,520 psi) is a lot more complicated than working with your typical parker or swagelok compression fitting

lines will be rated for at least 30,000 psi

Good to know. If nothing else, looking forward to seeing how this behaves.

This has probably been covered elsewhere, but has the CP4.2 not had the failures the CP4.1 shown thus far? Is this simply due to the lower pressures 1600 bar vs 2000? bar?

2004LB7 · Nov 2, 2013

Bump

I've been playing around with the idea of a flat tappet design.

i acquired a thrust bearing and two matching washers to allow the tappet to turn freely for even wear

i flipped over the roller "cradle" to see how it rides on the cam. not too sure i like the idea of the holes and laser etched markings on the sliding surface but i dont have anything else yet. i polished up the surface the best i could

thrust bearing fits nicely inside. 24mm and 15/16 diameters both fit great with just a little play to allow it to spin freely

This is how i have it assembled. Spring, thrust washer, thrust bearing, another thrust washer and then the piston with its (not sure of the name) part that pulls it back down

sits inside like this

the original and flat tappet. almost the exact same height

and installed

so far turning it by hand (with a nut and wrench on the end of the shaft of course) it seams to have the same resistance as the roller. the only thing is when it reaches the low spot on the cam it slaps the bottom as the cam has a flat spot. i think in order for this to work the cam would likely have to be re-profiled to smooth this out

2004LB7 · Nov 4, 2013

here is another idea, my favorite alloy to the rescue...

Tungsten Carbide, or more correctly "cemented tungsten carbide". i have a carbide rod that is 10mm x 100mm. fits the roller shoe just as well as the original roller. i just need to get my hands on a diamond cut off wheel to trim it down to size

slides in smoothly like the original roller

now if there was a way of making the shoe out of tungsten carbide and perhaps the cam too. now that would make a bullet proof HPFP

do you think it is worth cutting out a few rollers out of this rod?

JFettig · Nov 4, 2013

Keep in mind, its more mass.

Also, cam lobe profile probably is not optimal for flat tappet.

bhutchins · Nov 4, 2013

what is the brinnel hardness of the stock roller? how much harder is the carbide?

do yourself a favor, and have it properly cut and beveled if you want to use it. Cut off saw... yikes

2004LB7 · Nov 4, 2013

bhutchins said:
what is the brinnel hardness of the stock roller? how much harder is the carbide?

not sure one the hardness of the stock roller but a quick google check seams to indicate that hard chroming leave a surface of around 700+ brinnel. it is also my understanding that for the harder materials the use of a carbide ball is employed

-Hard chroming somewhere in the neighborhood of 700+
-Tungsten Carbide = 2570 (http://www.tungsten.com/mtstung.html)

very much indeed harder

bhutchins said:
do yourself a favor, and have it properly cut and beveled if you want to use it. Cut off saw... yikes

gosh no, that thing would glow bright red before you begin to cut through it.

i was thinking more on the lines of cutting it with a diamond cutting wheel on a dremal and then beveling it. there is a company near my work that i believes makes bits for lathes and milling machines that may be able to do this. i will have to stop by and see if they could cut it up for me

JFettig · Nov 7, 2013

With regards to the flat lifter... consider how the 2.0T engines are doing that have those, they switched over to rollers because it was destroying cams and engines.

Jesse_Boyer · Nov 7, 2013

JFettig said:
With regards to the flat lifter... consider how the 2.0T engines are doing that have those, they switched over to rollers because it was destroying cams and engines.

I tend to agree, unfortunately. Unless someone is very confident in the metallurgy engineering and could make sure the ULSD would be sufficient lubricant to prevent the destruction of the system, it's not the answer.

I still believe the correct answer is a roller, similar to a roller-lifter from a small-block, and a provision to prevent it from twisting out of alignment. Big roller cams have more lift (by far) and turn some crazy RPM as well. Thus, it's certainly viable to consider (however, it's one of the most elaborate, most expensive options.)

storx · Nov 12, 2013

Question @ 2004lb7

I just purchased a CP4.2 Common Rail Pump 0445010622-FP5, But i am wandering if the code is anything to be concerned about?? I didnt realize the FP5 tell after i bought it..

k^2 · Nov 12, 2013

So which is exactly the part that fails and desintegrates into pieces?

2004LB7 · Nov 12, 2013

k^2 said:
So which is exactly the part that fails and desintegrates into pieces?

please refer to post #55 & #72

it has not been determined 100% what is the cause but it appears that the roller stops turning and instead of roller slides then grinds across the cam. it has been speculated that it is the poor quality of US diesel or contaminants getting between the roller and shoe or wrong grade of metal/material used or perhaps a combination of all of them

storx · Nov 13, 2013

I wander if we could create a kit so you can just check the roller from time to time and replace it once it starts to show wear....

2004LB7 · Nov 13, 2013

storx said:
I wander if we could create a kit so you can just check the roller from time to time and replace it once it starts to show wear....

the only problem i see with that is if you have wear on the roller you most likely have wear on the cam and if you just replace the roller it will be short lived without replacing the cam as the new roller would then be riding on a rough cam surface

bassman5066 · Nov 13, 2013

I think the issue is, once you wear down the "diamond like coating"(not my words, that came from the self study guide) on the roller and cam, both are toast and it is a quick downward spiral that wears down the cam to nothing and sheds metal shavings all over the fuel system.

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storx · Nov 13, 2013

2004lb7 do you have an idea on the fp5 code on my pump

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2004LB7 · Nov 13, 2013

storx said:
2004lb7 do you have an idea on the fp5 code on my pump

Sent from my SGH-M919 using Tapatalk

sorry, i dont.

i believe 2micron could help you with this

2004LB7 · Nov 13, 2013

this might help

http://www.rufre.com/DetalleArticulo.aspx/en/-107841/

2004LB7 · Nov 16, 2013

so, with a diamond cutting wheel i was able to cut out two pieces for rollers for the carbide rod

and turned the rest of the rod into a scribe

GoFaster · Nov 16, 2013

The fundamental problem with this design is that there is no assurance that the roller will roll on the cam rather than slide on the cam.

Grab any cylindrical object with solid ends that you have handy. An unopened pop can will do. Lay it down flat on the table. Put a finger from your left hand dead center against one end and a finger from your other hand dead center against the other end and gently clamp it end to end, then use your fingers to move the roller that you have just made, in the direction that it wants to roll. And it does - It rolls on the table (because the friction from the roller against the table has a substantial mechanical advantage against the friction from your fingertips very close to the axis of rotation).

Now, with the pop can still lying flat on the table, cup your hand and put it over the pop can so that it fits closely around it, just like that cam follower rests in its holder (but obviously upside down and scaled up considerably). Now move around. What happens? Does the pop can roll on the table and slide against your hand? Maybe, maybe not - it's pretty likely to stay put against your hand and slide on the table. Depends how slippery your table is, depends how slippery your hand is. Depends how hard you push down. Depends whether you have cupped your hand far enough down the sides of the can.

A proper roller follower has to be designed to assure that it will roll.

2004LB7 · Nov 16, 2013

great analogy. the surface with the greatest friction will prevail.

i am just trying to eliminate a possible source of failure. i know that this will not stop the situation of the roller not turning but if the reason is the roller wearing and getting scratched up and this is the reason for it jamming then a carbide roller may help with this. of course this wont stop contaminates from getting behind the roller between the shoe and preventing it from tuning. what would likely happen with the latter is that the carbide roller would come out unscathed but the cam would suffer badly.

2004LB7 · Nov 16, 2013

got me thinking GoFaster,

doing some calculations and it looks like the roller and cam experiences approximately 14,600+ PSI between their contact surface. it may be more but this is the math i used.

-the roller is approximately 0.875" long at the contact surface
-not too sure on this one but guessed on this one at 1/128th of an inch wide (0.0078125)
-the spring puts about 100 lbs of pressure down on the roller during a static state

-0.0078125 * 0.875 = 0.006835938
-100lbs / 0.006835938 = 14,628 PSI

did i get this right?

the PSI would go up when it is pumping diesel as it is now also pushing the piston and the spring. i have no idea what this would be at

now, what PSI is this steel and chrome good for? is it possible that the roller is deforming slightly and the surface is failing from flexural fatigue? this would cause micro cracks and small flakes of chrome to come off and possibly jamb the roller in the shoe. i would think Bosch would have this all figured out but we have seen small changes to the design over the years so it seems bosch hasn't

thoughts?

Jason

kjclow · Nov 17, 2013

GoFaster said:
The fundamental problem with this design is that there is no assurance that the roller will roll on the cam rather than slide on the cam.

Grab any cylindrical object with solid ends that you have handy. An unopened pop can will do. Lay it down flat on the table. Put a finger from your left hand dead center against one end and a finger from your other hand dead center against the other end and gently clamp it end to end, then use your fingers to move the roller that you have just made, in the direction that it wants to roll. And it does - It rolls on the table (because the friction from the roller against the table has a substantial mechanical advantage against the friction from your fingertips very close to the axis of rotation).

Now, with the pop can still lying flat on the table, cup your hand and put it over the pop can so that it fits closely around it, just like that cam follower rests in its holder (but obviously upside down and scaled up considerably). Now move around. What happens? Does the pop can roll on the table and slide against your hand? Maybe, maybe not - it's pretty likely to stay put against your hand and slide on the table. Depends how slippery your table is, depends how slippery your hand is. Depends how hard you push down. Depends whether you have cupped your hand far enough down the sides of the can.

A proper roller follower has to be designed to assure that it will roll.

One thing missing in your analogy is the lubricating (?) film of diesel around the "popcan". With the lubricating film, the roller should not actually be in contact with the cam.

2004LB7 · Nov 17, 2013

One thing missing in your analogy is the lubricating (?) film of diesel around the "popcan". With the lubricating film, the roller should not actually be in contact with the cam.

so how is the roller supposed to roll?

i believe that the film strength between the shoe and roller is high enough that it rides on the diesel but between the cam and roller the film strength brakes down and this is what creates enough friction to turn the roller. otherwise why have a roller in the first place? if the film strength of diesel was high enough to keep the roller from touching the cam it would have been much more logical to just use a flat tappet.

storx · Nov 21, 2013

Hello guys,

I received my new pump in the mail. If you need any pictures to add to your collection let me know.

I do want to ask if we know the torque specs for all the bolts on the unit. I ask because i would like to take mine apart to inspect the insides carefully.. The pump i got is a 0445010622 manufactured 03/04

bhutchins · Dec 30, 2013

compliments of 2micron...

adapter plate 0.398" thick

fuel lines waiting to be formed for nearly $350 from highpressure.com (for 2 sets)

Inside the HPFP

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