BHC / ATL engine with Bosch tandem pump adaptor

depronman

A2OC Donor
Tonight, after some discussions through today with Andrew, I modified the Audi 'Spacer' fitted between the EGR and the ASV to allow the far superior Bosch Tandem pump to be used on the BHC / ATL engines
The Bosch pump technically only fits the AMF engine, the BHC and ATL were always fitted with the far less reliable LUK tandem pump. However the Bosch pump does fit the BHC / ATL engine, but the ASV (anti shudder value) fitted to the BHC / ATL engine is electrically operted and as such is far bulkier then the vacuum operated ASV on the AMF engine. This causes a clash on of the ASV with the Bosch Tandem pump on the BHC / ATL engines
A solution was found by another member on A2OC which is to utilise TWO of the spacers which Audi fitted between the EGR valve and the ASV, by fitting an extra spacer the ASV is pushed around 60mm towards the passenger side and as such clears the Bosch Tandem pump.
However there is a couple of problems caused by this modification -
1) the ASV is rotated by around 45 degres
2) the movement of the ASV to the passenger side means that the rubber elbow is bent for accutly which is not ideal

The solution I came up with is to cut the second spacer into two halves, so you have effectively two flanges with stubs of tube attached.
Then turn the outside diameter of one of them, down to 47mm Diameter by 12mm long
Then on the other half turn a bore 47.1mm diameter by 12.25mm long
The two parts will then fit together resulting in a spacer which is some 15mm shorter. Industrial loctite was used to bond the two parts togther after the orientation was set such that the tandem pump will be reverted back to its original angular position.
The end result once fitted to the car will be the tandem pump in the correct orietation put around 35mm nearer to the passenger side, this is enough to clear the Bosch tandem pump, releaves the strain on the rubber elbow and means that the pipe connection into the ASV works as Audi intended and needs no modification due to a different angle of the ASV.
I'm sure Andrew will add some pictures tomrrow after his friendly mechanic as fitted the Bosch tandem pump and the additional spacer

For now attached are the pictures of the modified spacer/ original spacer / ASV all screwed together

Service is available to anyone who needs it, PM me for further details
 

Attachments

depronman

A2OC Donor
Me too
40 years making aircraft does rub off even though at work is 30 years ago since I picked up tools
My toolbox these days at work is a laptop - how times change !!!

Cheers. Paul


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O07JESTER

Member
I love the solution,however in my case, I had to use a good idea and what basic tools I had at the time.im sure many ATL/BHC owners will be interested in your handywork :)

Martin
 

fhl

Member
I love the solution,however in my case, I had to use a good idea and what basic tools I had at the time.im sure many ATL/BHC owners will be interested in your handywork :)

Martin
I must also thank O07JESTER for helping me find an extension piece, for posting his work on the forum and for responding to my PM's. A picture paints a thousand words.

(Depronman) Paul's expertise made this additional modifications possible. After our dialogue yesterday, It was truly amazing to see him work with his CNC machine last night. His work is meticulous and his knowledge and experience admirable.

Thanks Paul for managing to carry out the extension piece mod in one visit and at such short notice so that I need not cancel my appointment at MDR autos in Mossley this morning.

Thanks also to audifan and other poster's regarding this Bosch tandem pump mod. If it were not for audifan, I would not have realised that the Bosch unit was thicker than the LUK unit and that it would interfere with the ASV for the ATL engine.

I will post some photos when the work is complete.



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cheechy

A2OC Donor
Good innovative piece of work chaps.

In relation to the difference in the pumps - is it merely just reliability or is the tandem pump capable of increased performance? Just thinking if the pump can in theory deliver more fuel then maybe the BHC and ATL maps could deliver slightly increased bhp and torque figures?
 

nod

Member
hi paul, i may well be interested in this mod, i think the bosch pump might be the way to go for my swap to running on veg oil, will pm later cheers nod.
 

fhl

Member
I must also thank O07JESTER for helping me find an extension piece, for posting his work on the forum and for responding to my PM's. A picture paints a thousand words.

(Depronman) Paul's expertise made this additional modifications possible. After our dialogue yesterday, It was truly amazing to see him work with his CNC machine last night. His work is meticulous and his knowledge and experience admirable.

Thanks Paul for managing to carry out the extension piece mod in one visit and at such short notice so that I need not cancel my appointment at MDR autos in Mossley this morning.

Thanks also to audifan and other poster's regarding this Bosch tandem pump mod. If it were not for audifan, I would not have realised that the Bosch unit was thicker than the LUK unit and that it would interfere with the ASV for the ATL engine.

I will post some photos when the work is complete.



Sent from my CLT-L09 using Tapatalk
Here are photos of the completed work. All sorted now and vacuum restored. No more hard brake pedal . Bosch tandem pump nozzle is screwed in unlike the LUK one it replaced. Bosch unit has very good build quality. To be fair though, the LUK unit lasted 215k.


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cheechy

A2OC Donor
Wow it does stick out quite a bit more to the right - any sign of wobble or is there plenty of support?
 

fhl

Member
Wow it does stick out quite a bit more to the right - any sign of wobble or is there plenty of support?
That was my concern too as the ASV is cantilevered through the 2 extension pieces to the EGR. However, Paul's shortened extension piece in the middle is solid and feels like the original cast alloy component.


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audifan

A2OC Donor
Excellent work all who contributed to this excellent solution. The Bosch pump in my opinion is the only way to go. The solution will be durable and almost looks like factory fit. Paul my hat is off to you yet again for your skills. Do you have a price for making the part for others who wish to convert to the Bosch tandem?
 

TAABVW

Member
Hi Paul,

I would also be interested in your "shortening of extension tube for Bosch tandem pump on ATL" service. Can you give a price asuuming part is supplied.

Thanks
 

depronman

A2OC Donor
I must also thank O07JESTER for helping me find an extension piece, for posting his work on the forum and for responding to my PM's. A picture paints a thousand words.

(Depronman) Paul's expertise made this additional modifications possible. After our dialogue yesterday, It was truly amazing to see him work with his CNC machine last night. His work is meticulous and his knowledge and experience admirable.

Thanks Paul for managing to carry out the extension piece mod in one visit and at such short notice so that I need not cancel my appointment at MDR autos in Mossley this morning.

Thanks also to audifan and other poster's regarding this Bosch tandem pump mod. If it were not for audifan, I would not have realised that the Bosch unit was thicker than the LUK unit and that it would interfere with the ASV for the ATL engine.

I will post some photos when the work is complete.



Sent from my CLT-L09 using Tapatalk
Can I also echo my thanks also to O07JESTER for the original idea and others who have pointed out the advantage in terms of reliability of the Bosch tandem pump over the LUK pump
This Mod makes the Bosch pump available to ALL of the A2 TDI engine range

Could I ask, who ever knows them, to post part numbers for the tandem pump and the extension piece. I've already had some interest in this remachined extension piece so having the part numbers (or anything else that is used to find them on ebay) would be helpful to those wanting to go this root

FHL always a pleasure, oranges are very tasty :) happy new year
 

depronman

A2OC Donor
Good innovative piece of work chaps.

In relation to the difference in the pumps - is it merely just reliability or is the tandem pump capable of increased performance? Just thinking if the pump can in theory deliver more fuel then maybe the BHC and ATL maps could deliver slightly increased bhp and torque figures?
from what I have read its a reliability thing, (no leaks) which is the +1 for the Bosch pump
Both pump (LUK & Bosch) deliver more than enough fuel to the injectors, infact 90% of the fuel is returned to the tank, it does a good job of cooling the pump / injectors etc, hence the floor mounted fuel cooler
Cheers,
Paul
 

depronman

A2OC Donor
Here are photos of the completed work. All sorted now and vacuum restored. No more hard brake pedal . Bosch tandem pump nozzle is screwed in unlike the LUK one it replaced. Bosch unit has very good build quality. To be fair though, the LUK unit lasted 215k.


Sent from my CLT-L09 using Tapatalk
That all looks perfectly OEM, The man from Audi would not complain :) There is more than enough length on the 'extra' spacer part, any future ones can be made a little shorter by extending the bore depth from 12mm to say 16 mm
I will adjust the CNC tapes accordingly
Paul
 
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depronman

A2OC Donor
That was my concern too as the ASV is cantilevered through the 2 extension pieces to the EGR. However, Paul's shortened extension piece in the middle is solid and feels like the original cast alloy component.


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the casting is of high quality with a nice fine grain structure, there is still in excess of 2.5mm wall thickness on the inner and outer parts of the machined extension piece, as such I have no worries about the integrity of the modified extension part
As stated above any more that I do will have a slightly deeper bore which will make the part a little shorter and a little stronger

Paul
 
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Reactions: fhl

depronman

A2OC Donor
Excellent work all who contributed to this excellent solution. The Bosch pump in my opinion is the only way to go. The solution will be durable and almost looks like factory fit. Paul my hat is off to you yet again for your skills. Do you have a price for making the part for others who wish to convert to the Bosch tandem?
If you supply the extension piece, then £30 + £3 postage
If anyone as a spare extension piece or can point me in the direction of one on ebay etc then I would like to get to the point where I have a machined on in stock so I can offer a quick turn around (as I do with check straps / wiper arms etc)

Cheers,
Paul
 

audifan

A2OC Donor
Bosch tandem F009D02799

Spacer I think
045129644 Believe there is one on ebay now. Seller Bullzbitz
 

depronman

A2OC Donor
Hi Paul,

I would also be interested in your "shortening of extension tube for Bosch tandem pump on ATL" service. Can you give a price asuuming part is supplied.

Thanks
see earlier post, £30 + £3 postage assuming you supply the extension piece

Cheers,
Paul
 
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