Engine Swap Notes for using Mk3 2.0L ABA Short Block with 1.8L 8V Head

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1. If you are installing the engine in a Mk1 or Mk2 Chassis you will find it easier to use the ABA short block and using your existing fuel injection rather than using the complete ABA engine, this makes it much easier because there is no wiring issues to deal with.

2. You will need the Mk3 ABA 2.0L distributor drive gear as well as a Techtonics distributor adapter bushing (103 140). This will allow you to adapt your original ignition distributor to the ABA block. (The 2.0L has a larger distributor hole and larger drive gear than the 1.8L)

3. If you are installing the engine in an Mk2 chassis (‘85-‘92 Golf or Jetta) get the ABA exhaust manifold and downpipe. You need the Mk3 downpipe or a TT downpipe (251 117S) in order to accommodate the taller block.

4. If you are installing the engine in an Mk1 chassis (‘75-‘84 Rabbit, ‘75-‘88 Scirocco, ‘80-‘84 Jetta, ‘80-‘93 Cabriolet, and ‘80-‘83 Rabbit Pickup) you will need the Mk2 or Mk3 dual outlet manifold in conjunction with a Techtonics conversion downpipe. They are available in cat (251 223, 251 112) or non-cat (251 114, 251 116) configurations.

5. The ABA engine comes with a breather tower on the front of the block. Mk1 and Mk2 cars are set up for a breather outlet in the valve cover. You will need a Techtonics breather block off plate kit (103 135) to solve this problem. This kit includes a 40mm freeze plug for the hole in the block as well. The CNC machined plate is drilled & tapped for mounting the CIS warm up regulator in the factory location (used on the early Mk1 & Mk2 cars).

6. The head gasket you need to use when installing a 1.8L head on the ABA block is from the 2.0L 16V and Audi 80 2.0L, (198 137) composite or (198 137M) multi layer steel. Do not use the 2.0L ABA head gasket as the oil drain holes are not correct. The head gasket alignment dowel pins will also need need to be changed to 6mm dowels (103 139). OE head bolts are a “stretch type” and should always be replaced. (103 103S) OE replacement bolt set or ARP head head stud kit (103 102U) can be used.

7. The ABA engine has 10:1 compression ratio and a knock sensor ignition system should be used. If your car wasn’t originally equipped with a knock sensor you can retrofit one from a ‘85-’87 GTI or GLI that uses CIS injection. 9.2:1 Compression is the most Techtonics would recommend on pump gasoline with out a knock sensor ignition. Techtonics offers piston machining service to lower the compression for $100, this includes chemical cleaning of the pistons as well.

8. The timing belt from the ABA 2.0L is used because the block is taller (109 052) It is recommend to replace the timing belt tensioner as well (109 055).

9. Timing covers from the ABA 2.0L need to be used as the 1.8L ones will not fit due to the block being taller

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