turning a aaz into a tdi

[colhel59]

I have the idea of using pistons from a ahu and head i willl needs to do soming with the pump als. but i was wondering what the best way to pull off this conversion. And would there be much benifit.. main reasone i am considing this is because i need a bore on my aaz block and the head has deep cracks inbetween the valves.
 thank in advance
 Colton

[rallydiesel]

Yes, you can use the AAZ block to make an AHU. Just like you mentioned, you'll just need the AHU or ALH pistons (a bit stronger) and the AHU head with the AHU pump/injectors. You can search posts by forum member jimfoo. He did this a few years ago.

[colhel59]

would i beable to have the potential to make more power in the long run going this route. rather then just rebuilding it as a IDI.

[rallydiesel]

You could probably have some more power potential going tdi but there are some high-powered idi's out there too. You'll have to swap in the electronics if you are keeping the ecu. Honestly, I think staying idi is more user-friendly for high power compared to mechanical tdi.

[rallydiesel]

How bad are the cracks in the head? It is very common to have cracks between the valves. They generally do not affect the performance.

[colhel59]

they look like they go all the way to the valve seat they look fairly deep just hesident just to leave them. the engine has about 300K ++ and it had definaly had the crank nose fail at one point in its life thellin from the deep valve impressins on the pistons.

[blackdogvan]

I believe you may have to do some fab work to get the crank position sensor mounted if you wnat to go etdi, mtdi is easy, no sensors!! The AAZ doesn't ahve the mounting bits for this but I can't say what would be required to add one to an AAZ block.

[rolo]

Used an n/a non turbo block and crank (AEF) to do this about 6 months ago, left the motor in situ, easy if you`re going mtdi, but you will need a tdi crank, a useful upgrade anyway, for its signal generator ,and  some modifying of the block-, drilling, tapping and grinding to fit the sensor, and the ability to get it in exactly the right place

[G60ING]

If you are going to spend all this time converting to a TDI why not just swap in the whole TDI long block?

[410]

I am currently running an aaz block converted to an mtdi.  I needed tdi pistons, head, injector lines injectors, glowplugs, wiring harness for the glowplugs, headgasket and a tdi valve cover.  Also a modded injection pump with tdi delivery valves. 

One thing I noticed was the top ring height between the aaz pistons and tdi pistons were different.  The top ring on the tdi pistons is closer to the top of the piston so if the aaz block has any kind of a ring groove worn into the top of the cylinder it should be bored out to the next size piston.  My two cents.  Everything else was very straight forward.

[colhel59]

I would be going with a m-tdi and getting a rebore plus new bearings. so for my pump i just need to swap the delivery valves nothing else??

[rallydiesel]

You need to get a full m-tdi pump built.

[410]

There is info on building your own mtdi pump in the faq section.  The best option for an mtdi pump is getting giles to build you one.  This costs money though.  I built my own and am happy with the outcome but some of the internal mods are quite difficult to accomplish and require making your own jigs and special tools.

[ChopSauce]

 - jigs ? Not necessarily, but it requires you know which genuine Bosch parts to use - instead of building custom ones. Don't ask me - I don't know either, but I own a pump entierely assembled with unmodified genuine Bosch parts.

[rolo]

Or use a land rover discovery pump