This is basically a copy of the PM i sent to xriss. The only think I hope here is that out of this the info ultimately is being used for personal use...not for those to make money off it by doing it for others. I have shared it with others who have done just that and I would have been all over it except for the fact that I just don't have that much "extra" money to buy extra pumps, etc. to do this... Anyways...
There are the hybrid pumps that people use which basically is taking an older turbo diesel pump from say an older VW IDI TD and using its mechanical guts and then swapping in the camplate and 10mm head from the electronic TDI pump into it. It works...isn't the best way for a few reasons. The base part of the pump used for the hybrid was made initally to work on the older, much lower injection pressure IDI engines. Therefore when turning the pressures needed to power the TDI engine needs the shafts can snap, as well as other things go wrong. Generally, all the hybrids I have seen don't put out the power potential they possibly could...or if they do...they don't do it safely IMO. There are those that swap the straight IDI VW pump onto the TDI as well...but once again...as mentioned, the IDI motors operate at about half the injection pressure that the TDI does...so, with the pump fully turned up...you'd only be getting to stock TDI hp/tq figures or maybe slightly over.
Then there is the method that I have gone about doing and we tried and tested my pump initially on my friends Synchro Vanagon Westfalia mTDI setup. I'm sure you all have seen or heard of Karl Mullendore. He was running a hybrid pump. I thought of using the Cummins 4bt injection pump which is the same style pump as used on the older IDI VW's as well as the TDI's, but this is a DI (direct injection) specific fuel injection pump. The cummins engine it was made for is similar to the VW TDI and operates in and around the same injection pressures. The pump has a larger mainshaft as compared to that of the IDI style VE pumps so it can easily turn the injection pressures needed for the TDI. They are also fairly easy to find too and the swap isn't all that hard. The smoothness at which they run the motor is amazing and the power to vouch. The only major modifications required is that you must swap the gov. components of a VW TD mechanical pump into the cummins gov. housing, or use an entire VW gov. assembly in the cummins pump. The cummins pump in stock form has a totally different style gov (as this came of delivery van style applications that rev. very low)compared to what is needed to supply fuel from 0-4800+rpms... the details would be for another post, on a more individual basis...
Let me know if you want more info, etc. or need help... I can provide whatever I can over the internet here and such. This isn't all the info just for the above purposes. I also know that Karl after testing mine was able to buy a few extras as well and might be willing to do them for people but there are a few parts that are "harder" to find and thus make it difficult to just do on a regular basis...
Here is also a site that sells "mechanical" TDI pumps as well, Karl pointed this out to me... in the UK I believe, seems like an honest guy and the pump he is using looks similar to my 4bt pump and Karls.
http://www.syncro-bernd-jaeger.de/EN...neuer_tdi.html
A little pricey...can be def. done for cheaper than that...but, its an option... just thought I'd throw the link out there to you...
There are other issues such as the injection pump sprocket to deal with using the 4bt cummins pump (cummins nose is shorter than that of the TDI pump nose) , but its a fairly simple fix and such...and the driveability and power of it is amazing. In my case I machined the beefy MKIV style injection pump pulley and turned it backwards on the hub...lines right up. For Karl's purposes he used a 1.9AAZ pump pulley (which is adjustable as well) and turned it backwards on the hub. Its a little less beefy in construction...but works. Its also still available through the dealer or WorldImpex... around the $50.00 price tag area. Would still need to find the "hub" the adjustable units set on though too. The other option is to machine the old 1.6 style pulley at the machine shop to fit properly on the Cummins pump nose. Alot of options...I personally liked the idea of the adjustable unit myself. I forsee "pre set" advance marks for say making a run on the track vs. normal highway driving, etc. just to easily set, adjust and check against the gauge by loosening three bolts in one location vs. 4 on the old style and MK3/B4 style setups...
Here are a few pics.
The MKIV style TDI pump vs. the Cummins 4bt pump (before modification of the gov. assembly) note the differences between the "noses" of the pumps...
Also, the MKIV style injection pump sprocket prior to machining
Partials of the difference between the cummins gov. assembly (RIGHT) and the VW TD style assembly (LEFT).
MKIV style injection pump sprocket after machining...had "bubble" removed from the front side of the sprocket so it could be turned backwards on the hub and line up the camshaft, etc. relative to the pump without hitting the injection pump bracket...
4bt pump with VW TD throttle shaft bushing transferred to 4bt pump as well as VW TD throttle shaft and caged gov. assembly. Still more to be done and more Karl and I are talking about...this doesn't detail everything...but you get the idea.
maybe Karl will see this and chime in on how he feels about it in his van. I can tell you though, when I heard it run... WOW
so smooth compared to all the other mechanical TDI's i've heard/seen and he said the power is just as impressive.
Joe