1.8T Tuning: Block and connecting rods
Here you'll get all the info you need to get to 500 PS and beyond with your 1.8T engine block and connecting rods. We show you where the engine is installed, how the block is built, its bearings, crankshaft, pistons and connecting rods and more! You'll also learn which tuning parts you need for your 1.8T engine to get the maximum performance out of it. There's something for every performance goal.
- 1. What cars have a 1.8T engine?
- 2. The engine block of the 1.8T engine
- 3. 1.8T engine main bearing/bearing shells
- 4. The crankshaft of the 1.8T engine
- 5. The con-rods in the 1.8T engine
- 6. The 1.8T piston
- 7. This is how the upgrade to 300+ PS will succeed.
- 8. What you need to upgrade to 400+ PS
- 9. This is how you successfully upgrade to 500+ PS
- 10. Do you have more questions about 1.8T tuning?
What cars have a 1.8T engine?
The following vehicles were equipped with the 1.8T engine:
- Golf MK4 GTI (1997-2005)
- Audi TT 8N (1998-2005)
- Audi A3 8L (1997-2005)
- Seat Ibiza (1999-2001)
- Seat Leon Cupra (2001-2005)
- Skoda Octavia (2000-2001)
The engine block of the 1.8T engine
There are two different engine blocks. The 058 engine block was installed up to the production date of May 2000. In the Audi B5, it is longitudinally mounted only. It has an internal intermediate shaft and an external water pump. 06A engine blocks, on the other hand, have no intermediate shaft, and the water pump is driven by the cam belt. They are installed in all vehicles with transverse engines.
1.8T engine main bearing/bearing shells
All four-cylinder engines have five main bearings. The main bearing shell is additionally equipped with two thrust washers. The main bearing shells are made of cast iron and can be upgraded to billet steel versions depending on the performance set-up. The threads of the main bearing shells are M10; the lengths vary between the 06A and the 058 engine, though.
The crankshaft of the 1.8T engine
All 1.8T crankshafts have a stroke of 86.4 mm. They are made of cast iron or are forged. There are two different wheels used to determine the engine speed.
The con-rods in the 1.8T engine
All 1.8T con-rods have a length (hole center to hole center) of 144 mm and a width of 24.9 mm.
- 06A engines have a 19 mm piston pin (except 225 PS models that have a 20 mm piston pin)
- 058 engines all have a 20 mm piston pin
The 1.8T piston
All 1.8T pistons have a bore of 81 mm and a compression ratio from 9.25:1 to 9.3:1. Some pistons are cast, making them relatively weak. The forged ones are considerably more rugged. Our innovative compression ratio calculator allows you to filter according to your engine code, and the compression ratio is automatically displayed.
This is how the upgrade to 300+ PS will succeed.
As of a desired performance of 300 PS, we recommend the use of upgrade pistons and con-rods. This combination only works when the cylinder walls are in good condition, though. You get matching combinations of pistons and con-rods for your 1.8T engine from us.
Con-rods with oil drilling hole:
The oil drilling hole is a hole that is present from the small to the large side of the con-rod (riffle drilled). Thanks to this additional oiling, the piston pin has a considerably longer service life.
What you need to upgrade to 400+ PS
1.8T cam belt system:
The cam belt system of the 1.8T engine is its great weakness. Often, the original belt pulley veers off, resulting in disastrous engine damage. To avoid this, our range includes a matching pulley with a high-strength guide pin. You also get from us reinforced ARP crankshaft bolts and our complete high-performance cam belt kit.
Main bearing supports
The main bearing supports of the 1.8T engine are cast and have an increased engine movement compared to the upgrade IE billet supports made of high-strength alloy steel. In addition, they reduce the wear on the main bearings. (For this, the bearing line of the crankshaft must be honed again in the block.)
This is how you successfully upgrade to 500+ PS
The crankshaft is made of cast iron. As of a certain performance, it makes sense to upgrade to a forged crankshaft. The engine is converted to a 2.0L through a change in the stroke to 92.88 mm. Take a look at our 1.8T stroker kit.
The piston pins are often neglected in conversions. From the aforementioned performance upward, it is important to use a specially reinforced piston pin. Piston pins that are too weak can break and result in severe engine damage.
Important: Products from previous upgrades are also needed.
You will find appropriate articles for your upgrade here: