AAZ pistons in ALH block

[RedRotors]

Any know if the AAZ pistona will fit in the ALH block ? I mean related to the piston pin height ? 1.9TD head will go on
top of that.

thanks,
Marc/

[theman53]

It works the other way, but you might have to use the rods from the AAZ.

Rereading the post I am not sure now. I know the 1z and AHU the swap is made, I am not sure on the ALH. I would still think if the rods were swapped with the pistons it would work. I think going the other way the engine needs honed as the rings are up higher on the TDI piston, but this way the ridge would still be below the TDI piston ridge.

[RedRotors]

honing the bloc won't be a problem, i was worry about the piston height, over the deck.. I don't want to shim the head
gasket..

[410]

It will work.  The center to center of aaz rods and alh rods is the same.

[theman53]

Well then if the ALH and AHU have the same rods dimentions as the AAZ then it will work for sure.

I was just saying the ridge about rings as when you go from aaz to tdi the block almost always needs bored or honed with a machine. Going this way you should be able to do the drill and stone hone and be ok.

[RedRotors]

It will work.  The center to center of aaz rods and alh rods is the same.

and the pin height in the both pistons are the same too ? Just making sure before spending $ on a new set of 1.9TD.

[theman53]

I would trade you for the TDI pistons

[rallydiesel]

I doubt the AAZ head will work on the ALH block. The ALH block is quite different from the AAZ/AHU.

[RedRotors]

hehe that's the problem with discussion forum.. someone will say it works, some other will say it won't. I will buy the head and pistons and tryit by myself.

[rallydiesel]

No I'm quite sure the ALH pistons are are interchangeable with the AHU and AAZ. I believe the top ring position is slightly different. But it's the head that won't work. You would need to use an AHU/1Z block with the AAZ head.

[theman53]

hehe that's the problem with discussion forum.. someone will say it works, some other will say it won't. I will buy the head and pistons and tryit by myself.

I will trade you the 1.9 IDI pistons for the TDI and you can play with little expense.

Sounds like you need to look at the bottom of each head and see if the passages are the same.
ALH ripped from prothe's site


And he has no pic of the bottom, but seems to me the oil drain will be the only thing modified. This is his AHU head

[410]

It will work.  The center to center of aaz rods and alh rods is the same.

and the pin height in the both pistons are the same too ? Just making sure before spending $ on a new set of 1.9TD.

The pin height is the same.  The only difference is the top ring groove is higher on the alh compared to the aaz but deck heights are the same.  I've compared them side by side.