Official Displacement Increasing Thread
This is the official thread for increasing the displacements in both the 058 and 06A blocks.
To answer the question, “should I go stroker or not?” it’s different for everybody. In my motor, I was going to drop in rods and call it a day. After disassembling my motor, I checked wall to piston clearance and I measured .004” which is too much. So I had to overbore. Since I was buying pistons and rods, I decided to just buy a crank at the same time. If you buy overbore pistons and later decide to stroke your motor, you will have to buy pistons again, which I was wanting to do so I did it all in one shot. Another thing that made me think about doing pistons from the beginning was that I wanted to lower the compression ratio so I could run higher boost on pump gas. Basically, if you are replacing your pistons and rods, you should go stroker.
First, you need to know which block you have in order to determine what course of action you need to take.
Here is how you can tell if you have an 058: you have an engine coded AEB or ATW, you have an external water pump, you have an intermediate shaft (IM shaft) for the oil pump, you have no knock sensors, you are drive by cable, ect…
Here is how you can tell if you have an 06A: you have an engine coded AWM, you have an internal water pump, you have no IM shaft, you have knock sensors, you are drive by wire, ect…
Displacements are as follows:
81mm bore x 86.4mm stroke = 1781cc (stock)
81.5mm bore x 86.4mm stroke = 1803cc
82mm bore x 86.4mm stroke = 1825cc
82.5mm bore x 86.4mm stroke = 1848cc
83mm bore x 86.4mm stroke = 1870cc
83.5mm bore x 86.4mm stroke = 1893cc
Now when you add a 92.8mm stroke crank to you engine you have the following displacements:
81mm bore x 92.8 mm stroke = 1913cc
81.5mm bore x 92.8mm stroke = 1937cc
82mm bore x 92.8mm stroke = 1961cc
82.5mm bore x 92.8mm stroke = 1985cc
83mm bore x 92.8mm stroke = 2009cc
83.5mm bore x 92.8mm stroke = 2033cc
I will not go into the 95.5mm crank from the TDI as I do not know enough to accurately inform people about making it work in either the 06A or 059 blocks.
Since this is for the B5 forum, I will start with the 058 block, since most of us have that. Stock bore is 81mm, pistons are generally offered in .5mm increments over stock, there are some exceptions. JE, Mahle, Wiseco, CP, and Supertech are the popular choices, not to say the only ones that are good. For rods, you use stock length and 20mm wrist pin. Scat, Pauter and Carillo are the popular choices, again, not the only ones that are good.
For using a stock crank, the process is pretty straight forward. You tear down the motor and bore the cylinders. Install is the reversal but with the exceptions of putting the new slugs in.
For stroking the motor, the process is much more involved. You need pistons with a lower deck height due to the increase of stroke. The same rod dimensions are used and if the stock height pistons were used, the pistons would travel 3.2mm too high and impact the valves. Not good as you can imagine. So custom pistons will be needed and they are readily available for order because luckily for us, others have been doing this and the design is already done. Which crank do you use? Well since you are 058 you must use an ABA crank from a MK3 Volkswagen. Pre OBD2 cranks are forged, post are cast. Chances are you won’t be coming anywhere NEAR breaking either unless you are going about a 35R or beyond. Now for the installation of the whole setup… A couple things will need to be done to make clearance for the rods due to the larger stroke of the crank. #1 The block will need to be grinded away by about 1.5-2mm on the side of the block away from the IM shaft. Cylinder 3 has a hump that the rest do not and that will need to be ground a bit more. The rods will actually clear without any grinding, but you should have at least .100” clearance in my opinion. #2 The cylinder 4 oil squirter will need to be moved away from the piston using a copper o-ring between the block and the squirter. You will also need to grind the corner closest to the back of the motor and closest to the cylinder. #3 The IM shaft will need to be modified. The gear will need to be machined down to a thinner size. The amount needed to be removed depends on the type of rods you use, mind you only a little bit, but it does matter.
For the 058 you will NEED the following to reassemble your motor:
Crank bearings
Main Bearings
Main Bolts
Head bolts
Flywheel bolts
Rear main seal
IM shaft seal
Headgasket (if you are going past 82mm bore a head gasket from a ALT will be needed)
Oil pan gasket
Front seal
Valve cover gasket set
You SHOULD do the following things as well:
Oil pump
Timing Belt
Rollers and tensioners
Serpentine belt
Water Pump
Thermostat
Now on to the 06A block things are a bit easier for a stroker. The same applies for the stock stroke builds, just bore and put in new pistons. The reason the stroker crank is easier to run is because nothing has to be clearenced. Just install your new rods, pistons and crank and you are good to go. You have several options for crankshafts. For drop in solutions you have the AZG and AEG cranks. The AEG and AZG are from MK4 2.0’s and are cast in construction. The other options are ALT and BPV which are from a B6 2.0 FSI found in Europe. They have the wrong oil pump gear and need to be modified to be used in this application. The ALT is cast and the BPV forged. If you have the correct oil pump gear pressed on, the ALT and BPV can be used just like the AZG and AEG, just drop in and go.
For the 06A you will NEED the following to reassemble your motor:
Crank bearings
Main Bearings
Main Bolts
Head bolts
Flywheel bolts
Rear main seal
Headgasket (if you are going past 82mm bore a head gasket from an ALT will be needed)
Oil pan silicone sealant
Front seal
Valve cover gasket set
You SHOULD do the following things as well:
Oil pump
Timing Belt
Rollers and tensioners
Serpentine belt
Water Pump
Thermostat
Now for the credits:
Issam Abed (wizard-of-od) for providing me with every possible crank option there is lol
Paul Calado (killa) for convincing me to go stroker with his write up
The original guys in this scene who pioneered the stroker stuff for us
And all the others I’ve probably missed
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Originally Posted by 317ssayzarc _update 3-22-08
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