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Engine Specific Info and Questions => mTDI Mechanical TDI Conversions => Topic started by: TDISammy on September 13, 2024, 11:57:13 am
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Hi all, I'm getting started on my first run working with a tdi motor and I've got some questions that need someone a little more experienced in ve pumps. I'm wanting to do an m-tdi conversion on an ahu so I'm looking around my area to find parts and I came across a listing for a mechanical pump near me.
Now here come the problems, firstly it's for what I believe is a mid-80s (83 works I believe) audi 2.0l 5 cylinder. Further research shows that this motor runs the pump ccw instead of cw like a tdi does, at least from what I can tell.
It also has a cold start device on what would be the block side of the pump when mounted to a tdi.
(https://i.imgur.com/bWU8wcs.jpeg)
(https://i.imgur.com/VCwHEP9.jpeg)
What I am curious about is:
1. Can a ccw pump be converted to a cw pump using the stock ahu internals and pump head, minus the governor assembly and so on for an m-tdi?
2. Do I have enough clearance on the ahu to run the factory audi cold start device?
3. Does the audi pump body even accept ahu internals and pump head?
P.S. This pump is listed as needing a rebuild, which I'm not as concerned about as I'm a truck mechanic by trade and I'm a quick learner. It's only $100 but I wanted some opinions on if this pump is even usable before I take a gamble on it.
Thanks guys
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I don't think a pump that spins the wrong way can be used.
Because of the governor spinny parts inside.
Just took a look and there actually might be room for a cold start lever behind the injection pump on an AHU.
Might need some grinding on the bracket but there is room behind it, unlike the ALH setup.
I'm not sure what internals can be swapped into the audi 5 cylinder pump.
Keep in mind. There is a way to turn a cummins 4BT into an MTDI pump, but only for the AHU.
Here's some messages I got from libby:
Yes, the 4BTA will bolt up to the AHU pump bracket. The sprocket offset is wrong, though, as is the dynamic advance and the governor spring.
There is no stock sprocket that will fit the Cummins pump with the correct offset for the belt. Best way IMO is to use a 1.6 sprocket and have it machined to accept the larger diameter mainshaft of the Cummins pump.
All of the VW larger diameter mainshafts have the 'long snout'. The Cummins pumps have the short snout like the 1.6, but have the larger diameter shaft. The TDI mainshaft cannot be used because the TDI pumps did not use a governor assembly and the shafts do not have the cutouts for the little rubber things that hold on the governor gear. The shaft is incredibly hard metal and would be very difficult to machine the cutouts. MUCH easier is to use the 1.6 shaft but have the taper enlarged to match the larger diameter shaft.
( I think he meant to type the "1.6 sprocket")
Libby has done some messing around with this and has a couple springs for inside that help with the different RPMs these engines run at.
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You need a different pump. You can buy a pump from a Land Rover 200 / 300 TDI, it is nearly bolt on (you will need to open up the hole in the mounting bracket a bit but otherwise it is pretty straight forward). Or if you can find an AAZ and AHU pump you can send them off to Performance Diesel Injection in Ontario and Giles can build you one....