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Engine Specific Info and Questions => IDI Engine => Topic started by: DieselVanagon on December 21, 2009, 09:58:27 pm

Title: TDI block for IDI setup
Post by: DieselVanagon on December 21, 2009, 09:58:27 pm
Could an AHU "short block" be used with a 1.6 non turbo head and injection pump etc.
Title: Re: TDI block for IDI setup
Post by: TurboJ on December 22, 2009, 06:02:12 am
Well... You can if you use IDI pistons. I've seen a couple of engines that have a 1Z/AHU bottom end and AAZ / 1Y head, with AAZ pistons. They fit the TDI con rods exactly, and the TDI rods have the same dimensions as the AAZ rods, while the crank also shares dimensions between AHU/1Z and AAZ.
Title: Re: TDI block for IDI setup
Post by: 55eta on December 22, 2009, 07:16:19 am
yup runing a 1z with aaz pistons and abl head and oil pick up /sump
Title: Re: TDI block for IDI setup
Post by: RabbitJockey on December 22, 2009, 08:28:59 am
i wonder how an aaz would run if someone used tdi engine management with a custom chip.  thatd be cool
Title: Re: TDI block for IDI setup
Post by: boxer246 on December 22, 2009, 08:58:25 am
The poster specifically asked about 1.6 head with AHU block, and I think Andrew's answer was for that.  And he's right, you can't put a 1.6 mechanical lifter head on a AHU block.  For starters it has only one oil drain hole whereas that AHU block would have the usual later style two drain holes.  Dimension wise, it may be possible to put a later 1.6 hydraulic lifter head on a AHU block....but I havent compared the length of a 1.9 head to a 1.6.  You would then have to run AAZ pistons and I just don't see any possible benefit to doing this.  If you were to go to that trouble, you would be silly not to just use a AAZ 1.9 head as well. 
Basically, an AAZ and AHU block is the same with some small differences.  AAZ rods have weights on the big ends, IIRC the AHU rods do not, AHU crank has position sensor plate on it, AHU pulley end of crank has D shape rather than a keyway, AHU block has hole for crank position sensor, etc.
Title: Re: TDI block for IDI setup
Post by: 55eta on December 22, 2009, 09:51:40 am
no mention of mechanical head and perhaps hes not got a aaz head? i was ansewering to the {you can not mix and match idi and tdi blocks and heads} wich you can poviding you use idi pistons
Title: Re: TDI block for IDI setup
Post by: RabbitJockey on December 22, 2009, 09:52:54 am
a hydro head would bolt on an ahu block, and it would probably run.  and it would probably run like ***, the compression ratio would be extremely low.  the compression ratio of a tdi with just a flat head that has no combustion chamber is already 19:1, then with the pre chamber in the 1.6 head youd be getting down into gasoline compression ratios.
Title: Re: TDI block for IDI setup
Post by: truckinwagen on December 22, 2009, 12:43:16 pm
a TDI block with AAZ pistons would work with an IDI head.

and as luck would have it, I have a couple sets of AAZ pistons for sale right now!

I would use an AAZ head and not a 1.6, the compression ratio would be excessively high if a 1.6 head were used.
Title: Re: TDI block for IDI setup
Post by: DieselVanagon on December 22, 2009, 06:46:49 pm
Thanks, Andrew answered my question since my intention was not to mix match other parts but simply to use a 1.6 head and injection system on a TDI block.
Title: Re: TDI block for IDI setup
Post by: burn_your_money on December 22, 2009, 07:20:39 pm
One major difference between the TDI and AAZ block is the lack of the crank position sensor on the AAZ block.
Title: Re: TDI block for IDI setup
Post by: Powered by Spearco on December 22, 2009, 09:06:51 pm
Has anyone ever seen those no name brand 1.6 converted to 1.9 engines. I think they were called GEX engines. Reason for asking is that the block is a 1.9 "unknown code" and the head is a 1.6, its stamped on the front.
How did they make theres run with that setup?
Sorry for the hyjack question.
Title: Re: TDI block for IDI setup
Post by: RabbitJockey on December 23, 2009, 05:25:06 am
a TDI block with AAZ pistons would work with an IDI head.

and as luck would have it, I have a couple sets of AAZ pistons for sale right now!

I would use an AAZ head and not a 1.6, the compression ratio would be excessively high if a 1.6 head were used.

i would use an aaz head either way, but a 1.6 head will work, i think the cr ends up as 25:1.  hill folk has an aaz mk2 coupe with a 1.6 head
Title: Re: TDI block for IDI setup
Post by: Rabbit on Roids on December 23, 2009, 09:54:10 am
the CR of a 1.5 is 24.5:1, so is a half a point really gonna make that big of a difference.?
Title: Re: TDI block for IDI setup
Post by: rabbitman on December 23, 2009, 10:53:18 am
the CR of a 1.5 is 24.5:1, so is a half a point really gonna make that big of a difference.?

The 1.5 is actually 23.5:1 and the 1.6 is 23:1 ;D
Title: Re: TDI block for IDI setup
Post by: Rabbit on Roids on December 24, 2009, 09:45:07 am
the CR of a 1.5 is 24.5:1, so is a half a point really gonna make that big of a difference.?

The 1.5 is actually 23.5:1 and the 1.6 is 23:1 ;D

oh yea, thats it. i knew the 1.5 was a half point higher tho.
Title: Re: TDI block for IDI setup
Post by: maxfax on December 26, 2009, 08:38:37 pm
The engine that I welded all the cracks is a mis mash of parts..  1.5 block and head with a 1.6 rotating assembly....  It's been running with about 25:1 compression almost 150,000 miles..  Other than really easy cold starting it seems to be right on par with my other proper 1.6's as far as power and economy..  Don't think I'd throw a hairdryer at it though....
It has blown 2 HG's now but was it the compression, or the crappy head bolts and the cracked block that followed?   
Title: Re: TDI block for IDI setup
Post by: Rabbit on Roids on December 28, 2009, 09:03:39 am
my bet would be the crappy head bolts and cracked block. thats what happened to my last 1.5 engine. the bolts failed then the gasket took a dump.
Title: Re: TDI block for IDI setup
Post by: maxfax on December 29, 2009, 07:35:18 pm
That's what happened to every VW I have owned and driven..  (6 to be exact)  A few times on a couple of them to be exact..  The mis matched, cracked and welded, red haired step child has been the most resilliant of them all..

 Finally I have exhausted my supply of 11mm blocks, and sold off all but one of the 11mm heads...  I'm movin on up to 12mm stuff now..   I can move on to breaking new things now!  ;D
Title: Re: TDI block for IDI setup
Post by: maxfax on December 29, 2009, 09:42:23 pm
I guess it's time to ditch the 8-tracks for a cassette player...  :-\
Title: Re: TDI block for IDI setup
Post by: Rabbit on Roids on December 30, 2009, 02:42:28 pm
That's what happened to every VW I have owned and driven..  (6 to be exact)  A few times on a couple of them to be exact..  The mis matched, cracked and welded, red haired step child has been the most resilliant of them all..

 Finally I have exhausted my supply of 11mm blocks, and sold off all but one of the 11mm heads...  I'm movin on up to 12mm stuff now..   I can move on to breaking new things now!  ;D

i hear ya on that one. im not messin around with no more 11 mil blocks. i just gotta find another 12mil block to put my 1.5 into.