Official Displacement Increasing Thread

[317ssayzarc]

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

[317ssayzarc]

reserving this spot for additions which im sure will be needed

i need these pics added onto the post that i reserved in my engine build sticky... plus on the original post i need the 6.4mm changed to 3.2mm, mistake on my part lol...

[killa]

reserving this spot for additions which im sure will be needed

Write up looks dead on
keep on

[94jedi]

now this is the stuff the community needs. great work. looks like AZ is turning the corner.

[Beemer832]

looks like i'll be running the 92.8mm stroke crank with the 83mm bore "next" time....

what is a better block to do this with? 058 or 06a?

thanks
josh

[ModifiedA4]

How does compression ratio figure into all of this?

[ILoveT]

I thought you said this was going to take a week Jake.

[317ssayzarc]

looks like i'll be running the 92.8mm stroke crank with the 83mm bore "next" time....

what is a better block to do this with? 058 or 06a?

thanks
josh

06A but the accessories are different... It's really too much of a pain to convert it, just do it with your 058, it was no big deal for me to clearence the rods

[Beemer832]

i would have, but I am already in deep with rods, pistons, and so forth. i just want to get my car back on the road. the next engine I build will go with the new crank and better rods and pistons.. the twin scroll manifold mike mentioned sounds pretty taunting.. maybe that engine can go into my a4 racecar i always wanted to build.....

-josh

[317ssayzarc]

How does compression ratio figure into all of this?

I could get all into the physics of compression ratios but heres and easy way to understand it...

PROS
Higher CR:
More power off boost
Less lag

Lower CR:
More boost on pump gas
More timing

CONS
Higher CR:
Less power in boost
Less boost on pump gas

Lower CR:
More lag
Lower vacuum to an extent

[317ssayzarc]

Write up looks dead on
keep on

Thank you Paul

[Nebone]

These engine build threads just keep coming. They should be stickied so no search is needed. I guess you forgot about my brakes Jake and had this eaxtra time to write this thread. :)

[317ssayzarc]

I wrote it in an hour between 1-2 AM Sebastain!

Take it easy! Try greasing em up first, save me some valuable time to build my motor!

[ModifiedA4]

I could get all into the physics of compression ratios but heres and easy way to understand it...

PROS
Higher CR:
More power off boost
Less lag

Lower CR:
More boost on pump gas
More timing

CONS
Higher CR:
Less power in boost
Less boost on pump gas

Lower CR:
More lag
Lower vacuum to an extent

thanks!

It seems like for people who like to drive turbos, LCR is mo'betta. Though maybe a tracked car would favor a HCR.

[317ssayzarc]

thanks!

It seems like for people who like to drive turbos, LCR is mo'betta. Though maybe a tracked car would favor a HCR.

Depends on what kind of track... You typically would use a lower CR for dragging and a higher CR for road racing

[Nebone]

I predict your motor will be mint. Info here is great. Running more boost with LCR would definitely benefit 1/4 mile races.

[maxspeed]

Im glad all the coil pack and intake threads are being replaced with engine building threads and new turbo options. keep up the good work fellas

[AudiA4_20T]

good stuff, I wish I had this list when I was doing mine

[Issam@INA]

thanks!

It seems like for people who like to drive turbos, LCR is mo'betta. Though maybe a tracked car would favor a HCR.

Really depends on the user and what he feels like putting in his gas tank.
Most people favour lower CR because if you were on a High Compression Ratio then a tank fulled with race gas every week WILL BREAK YOU.Lower CR is more forgiving to "your mistakes".

[SilverB5A4]

Wow i was under the impression that the 06a block had to be clearanced for the rods as well with the 2.0 crank

[317ssayzarc]

nope

[dougyfresh]

I presume the AMU block (225hp TT) is also an 06a..?

If so, then it'll bolt up in the B5/B6 A4 chassis longitudinal. Correct?

[317ssayzarc]

its 06a and the only difference is the webbing on the side of the block, nothing to worry about for any swap what so ever

[dougyfresh]

its 06a and the only difference is the webbing on the side of the block, nothing to worry about for any swap what so ever

Thanks for the info!

[killa]

Thanks for the info!

Not all 058's need block shaving, the 9A for example is already a bubble block and will not require any grinding.

[t1demont1]

What cars had a 9A bubble block?

[mugattu]

What cars had a 9A bubble block?

90-92 vw gti's with a 16v use 9a blocks.

[kovalevandrew]

Hi,

My motor is an APU code. Want to go as big as i can and retain some sort of reliability... No idea what config it's got as stock. Not much about it online either.

What should i be looking at...?

[317ssayzarc]

Hi,

My motor is an APU code. Want to go as big as i can and retain some sort of reliability... No idea what config it's got as stock. Not much about it online either.

What should i be looking at...?

Well essentially you will want to go with the 92.8mm stroke and 83mm bore... Is your water pump timing belt driven or not?

[kovalevandrew]

Yeah, it's belt driven, just put a new one in.

So i'd be going up to 2009cc...?

[317ssayzarc]

Yeah, it's belt driven, just put a new one in.

So i'd be going up to 2009cc...?

Well of course its belt driven, but more specifically timing belt?

And almost 2009, you'd be getting 2008

[kovalevandrew]

Yes, belt driven, sorry.

It's not going to be my daily drive, but i'm thinking of going GT3076, or bigger.

[317ssayzarc]

Yes, belt driven, sorry.

It's not going to be my daily drive, but i'm thinking of going GT3076, or bigger.

Mostly street/pump gas use? Whats your goal of this car?

[kovalevandrew]

Yeah, want to be able to run pump gas still. I use 95 already.

Want to use it to do the occasional track day, as well as the weekly drag events we have here.

[317ssayzarc]

I'd suggest 2008cc motor with 9:1 compression ratio and a 3076R .63ar and a big port head with springs, exhaust valve guides and exhaust valves

Let me know if you need help with ordering any of those things or anything in general

[kovalevandrew]

That's pretty much what i've had in mind. What am i going to be looking at here from an output point...?

As far as i know i have a small port head, so i guess i should start looking around for one then. Anything i need to look out for in particular...?

[317ssayzarc]

That's pretty much what i've had in mind. What am i going to be looking at here from an output point...?

As far as i know i have a small port head, so i guess i should start looking around for one then. Anything i need to look out for in particular...?

Over here we look for AEB heads. As far as I know thats the only big port head. Here's a pic of my big port head with a little bit of work:


And heres pics of a small port head with big port gasket on it:



You should be around 400awhp or so on pump gas


Edit: shameless plug, I have a spare AEB Ill let go for 500+ shipping

[kovalevandrew]

Only slightly bigger then.....

I wonder what shipping to South Africa would be for that...

Might be a stupid question, but can't one grind out the small port...?

[317ssayzarc]

Only slightly bigger then.....

I wonder what shipping to South Africa would be for that...

Might be a stupid question, but can't one grind out the small port...?

Nice ninja edit, but I caught ya!

I thought the same thing, shipping wise...

You can get close but the water jackets in small port heads dont allow you to go as big... If you get reeeallll close to those water jackets while porting you can get close...

[kovalevandrew]

Hahahaha! Ninja madzkillz man!
Ok, so small port bad, big port good... Noted. How much porting can be done on the big port head...?

Will go looking for a new head sometime this week, plenty of scrapyards around here. Anything i should be on the lookout for, or stay away from...?