xr4tic

I tore apart the 1.8T block and did some comparisons.

First, the piston dish is 6cc, not 8cc as I first measured. This makes the compression ratio about 9.15:1 or so.

Second, and this was a surprise, the 1.8T crank is CAST, not forged like I originally thought.

Here's the pics (hosted on my home PC, I hope it works

The top crank is 92.8mm (2.0), the bottom is 86.4 (1.8) If you look closely, you can see the thin casting line on the 1.8, compared to the thick forge line for the 2.0
<img src="http://johnbaas.dyndns.org/2point0/audi_vw_crank_match_lo.jpg">

Side view of the cranks
<img src="http://johnbaas.dyndns.org/2point0/audi_vw_crank_match2_lo.jpg">

The auxilliary shafts, 1.8T on the left, 2.0 on the right, drives the oil pump for both motors, and the distributor for the 2.0 I will be using the 1.8 shaft (no distributor). Notice the pulley and shaft gear size differences.
<img src="http://johnbaas.dyndns.org/2point0/audi_vw_aux_match_lo.jpg">

Different views of the 2.0 (left) vs 1.8 (right) pistons and rods.
<img src="http://johnbaas.dyndns.org/2point0/audi_vw_rod_match_lo.jpg">

<img src="http://johnbaas.dyndns.org/2point0/audi_vw_rod_match2_lo.jpg">

<img src="http://johnbaas.dyndns.org/2point0/audi_vw_rod_match3_lo.jpg">

<img src="http://johnbaas.dyndns.org/2point0/audi_vw_rod_match4_lo.jpg">

Comparison of the fronts, 2.0 right, 1.8 left. Notice the height difference that allows the long rod to be used.
<img src="http://johnbaas.dyndns.org/2point0/audi_vw_block_frt_match_lo.jpg">

Rear view, 2.0 left, 1.8 right:
<img src="http://johnbaas.dyndns.org/2point0/audi_vw_block_rr_match_lo.jpg">

Side view #1, 2.0 right, 1.8 left:
<img src="http://johnbaas.dyndns.org/2point0/audi_vw_block_side_match_lo.jpg">

Side view #2, 2.0 left, 1.8 right. It's hard to see, but the turbo coolant return is there on the 1.8 You can also note that the 1.8 doesn't have any freeze plugs. Wierd.
<img src="http://johnbaas.dyndns.org/2point0/audi_vw_block_side_match2_lo.jpg">


For the most part, all of the accesory mounting holes are there.
I noted two exceptions:
1. The mount for the turbo brace is gone, not a big deal, since there looks to be an extra boss available (down lower) that could be used.
2. The mounts for the pass side engine mount bracket is different. Luckily, the bracket has holes for both configurations.

Here's another snag, the distributor hole is bigger on the 2.0 This means the plug from the 1.8 will not fit. I'll have to look through ETKA to see if maybe there is distributor-less 2.0 that uses a bigger plug, otherwise, some sort of adapter will need to be made. This plug keeps the gear on the oil pump shaft, so it's kind of important

All the tranny bolt holes appear to line up as well.

After inspecting the 2.0 block, there is a ridge in the bore, so I'll be boring it out to 83mm, which means I'll probably be getting some Forged JE pistons. I plan on keeping the stock rods, they look just as good as the 1.8 rods. I'll just have them reconditioned.

xr4tic

The cost incurred will be the same either way, so it just makes sense to try and do it the long rod way.

I'll be using the stock cams for now, they are easy enough to swap out while the motor is in the car, and I know the motor is running OK.

DustysA4

When you say that a few people are doing the kit for the street, is somebody already working on software for it? Or is the engine management swapped out?

Also, I'm guessing the pistons are forged as well?

CMH

yes they are forged, they sell JE pistons.

DustysA4

Nice....sounds like a good option for when I'm pushing 100k miles.

4kq

The original NA Audi 4 cyl. blocks were different from the VW blocks (deck height, etc.), did they have the oil return holes like the 5-valve head?

The freeze plugs were to help remove the casting sand, they figured out how to just use the end freeze plug hole.

Neat project. I too had thought we had a forged crank in the 1.8T, and that we had a fairly long stroke motor.

DustysA4

I think a guy named Billy1.8 was the one that discovered that.

xr4tic

so I don't know about the oil holes. I would assume they wouldn't, because the ABA uses an 8V head, which I'm guessing is setup similiar to the old 8V heads on the older "low" blocks.

J. Daniel

The deck of earlier 1.8 8V blocks are just like the ABA. 1.7 and earlier engines have yet smaller oil drain back holes.
Apparently, 16V blocks have the same deck as their contemporary 8V's.

hoTTub

I am not positive but I dont think there was a distributorless 2.0 only VR6, 1.8T