The purpose of this thread will be to help everyone who is planning on going BAT and building their engine to become a bit more informed. I will try to keep this thread updated as best as I can. Information regarding this thread should be limited to BPG,BPY, and BWT engines, or their improvement by adding similar 4 banger engine parts. There is alot of information about building this engine on this forum but it is so scattered between builds and the general forum that I think its important to put it all together so we can have a useful resource. PM me any information you would like to have added with a few resources to validate its credibility.
Failures:
Cam Follower - The HPFP breaks wears through the Cam Follower, and can cause bits of metal to go throughout your engine as well as ruin your camshaft/HPFP/ Cam Follower. Covered under Warranty until 120k/10yrs. Discussion: http://www.audizine.com/forum/showth...ollower%28s%29 DIY :http://www.audizine.com/forum/showth...IY-in-PDF-form
Rocker Arms - At High RPM's the rocker arms have been known to pop off and cause engine seizure as well as bending valves and damaging pistons. This happens most frequently past 6500 Rpms. This happens due to the hydraulic lifters that are under the rocker arms. The lifters bottom out at these high speeds and cause the rocker clip to break, sending the rocker loose into the engine to cause problems. With the Ferrea lifter shims the lifter is simulated as pumped even when the lifter is depressed so that it can no longer bottom out, this prevents rocker clips from breaking.
Variator - The exhaust camshaft variator has been known to fail and lead to catastrophic failure. Audi has put out a revised part number that should not fail.
Sheared Crankshaft Timing Belt Gear - The 2.0t crankshaft timing belt gear slips off of the crankshaft itself at power above 350hp. If you plan on making more than 350hp, plan on adding Integrated Engineering's Dowel pin kit to your shopping list. http://www.intengineering.com/fsi-2-...l-pin-kit.html
Engine Modification:
1.8T oil pump - Required precision machine work to create two new holes in the block. Eliminates the Balance Shaft assembly, reduces the rotational mass by reduction of the Balance Shaft, and with increased volume, allows you to run 2 qts extra oil. In addition to having 2 qt's extra this allows you to extend oil change intervals and it will keep your oil slightly cooler.
Balance Shaft Delete - Requires taking a dremel to the balance shafts and cutting them off. Reduces rotational mass, but does not allow for additional oil capacity. Keep in mind the balance shafts spin at 2 times the speed of the crank. This means at 8k Rpms the balance shafts are spinning 16k rpm.
Also absolutely make sure to balance your rotating assembly at a machine shop. Otherwise you will feel harsh vibrations from an unbalanced engine missing the balancing assembly. Make sure to not remove the sensor wheel on the crankshaft, removing the screws that hold it will ruin the sensor wheel and you will have to replace it. Plus there is just no reason to remove it unless it is harmed.
Thing's you might not have known
Cylinder Wall Coating - The 2.0T FSI engine has a special graphite coating on the inner cylinder walls. This coating helps to reduce cylinder wear. Honing or boring will remove this coating. Unless you are absolutely positive on increasing your bore, then run Wossner 82.5mm pistons. If you are deciding on boring, 83 or 83.5mm pistons will work from either JE, Mahle (OEM piston manufacturer), or Wossner.
Piston Metal - There are two types of alloys that pistons are made out of for our cars. 2618 and 4032. Mahle and JE make 2618 alloy pistons for our cars. 2618 is an alloy that contains less than 5% silicon, usually about 3% However in some cases no silicon is used. Whereas the 4032 pistons from Wossner have around 11% silicon. Silicon % is important because it determines a few of the characteristics of a piston. For example a higher silicon % piston will expand less with heat because silicon expands less than most any aluminum alloy. A low silicon piston will expand more as the engine warms up, which requires larger clearances so that when the piston warms up and expands there is no damage to the piston or cylinder walls. This can often lead to piston slap, a loud "slapping" noise as the engine warms up since the piston hasn't expanded there is some wobble room for the piston when its cold and it can be a bit noisy. These are the disadvantages of a 2618 piston vs a high silicon 4032 piston. The advantages are that because silicon is not as tough as aluminum, you lose strength in the piston as you increase silicon content. So while a 2618 piston may be noisy or you may have to wait for it to heat up properly, the advantage is that it is much stronger than a 4032 piston. This isn't to say that a 4032 piston is weak, but rather that under severe predetonation and misfires, a 2618 piston will be much better than a 4032. On the other hand its important to note that the pistons in the B7 A4 are forged, and we can run upwards to 30 psi on the stock pistons. So naturally purchasing an aftermarket 4032 piston that is stronger than stock pistons should yield sufficient power for most BT builds. When I spoke with both IE and Wossner, both companies had told me they had seen their pistons in builds in excess of 700hp. The FSI market has not reached that point so I think its safe to say that running a 4032 will not be a problem.
Compression - The primary objective of engine building is to modify an engine to be capable of handling the power that will be added. For this reason it is a good idea to lower your compression if you are building a block for a BT build. A lower compression rate allows you to run higher boost without detonation. In an engine running high boost with a high compression ratio detonation can occur because pressure inside the cylinder walls increases so rapidly and powerfully that the air and fuel mixture can ignite by the heat generated by the pressure. This causes an off sync combustion, detonation.
Rotational mass reduction. - Reducing weight is a great alternative to adding power to your car. For example many people replace the dual mass flywheel found at the back of our crankshafts with a single mass flywheel so that Rpms can rise and drop faster, it allows the engine to move quicker. The same concept applies to the rotsting mass inside the engine. The crank is the heart of the engine, and everything attached to it directly or indirectly is slowing it down. For example, indirectly, the air conditioning attached to the serpentine belt requires power from the crank to rotate it and power the air conditioning unit. However this slows the engine down and robs it of power because it could be spinning more freely and faster if the air conditioning pulley was not attached to the engine. The same concept applies to the balance shaft delete. When you cut the balance shaft gears you are removing a weight that would otherwise slow down the engine. While the balance shaft/oil pump gears still attach to the crank by the oil pump chain, the rods that hold the balance shafts spin freely now because the balance shaft gears are no longer connecting and creating a frictional counter force to slow the crankshaft. This information is important because it applies to pistons and rods as well. The heavier your pistons and Rods are the slower your engine will spin. Ideally you want a perfect combination between strength and weight. This will give you a strong quick revving engine.
Int Engineering Rifle Drillng - Integrated Engineering offers you the opportunity to have a tiny passageway drilled through IE rods, it helps lubricate bearings better as well as cool, for $100 its well worth it.
Stroker kits:
The 2.0T has a great stroke ratio, However other options do exist.
2.1 L - For this kit you need an mk4 ALH Diesel crankshaft, best luck is a junkyard or possibly VWvortex.
2.2 L- For this kit you need the Eurospec 2.2 crankshaft as well as custom pistons and rods. The Block will also have to be swapped out for a Diesel ALH block.
Running 1.8T parts on the 2.0T
Fueling issues - Due to the fueling constraints that so many FSI builds run into, a switch in heads to a 1.8T 20v(b6) head can be a great help with fueling. With the 1.8t head you eliminate the precision of FSI fueling, but it also removes the fueling constraints. The 20V head will bolt up into place our 16V head goes, the only issue is finding the correct sized timing belt.
Thrust washers - The B6 cylinder block(06B) and b7 cylinder block (06f) have minor differences in that the 06f block has the cylinder wall coating. However the 06F does not have the thrust washers around the third main bearing that the 06A block has. This lack of thrust washers makes the 06F block more susceptible to "crank walk". Edit, apparently some blocks do have these thrust washers, while not all 06f blocks do.
Feel free to PM me and I will add more information to this thread or correct it. I am still in the process of learning alot about this engine so I am sure I may have some incorrect info.
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Originally Posted by mec
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