2.0l 16v block to 8v (9a to 3a specs)

[bpederndern]

i am hoping that someone can confirm that this is as straightforward as i am hoping it is.

i have a rebuilt 9a block sitting in my room ( doesn't everyone i just picked up a 88 golf with a digifant motor. the bottom end may need to be replaced in it. i no longer need the 16v block for the car i built it for. ''


is it possible to conver the 16v block (9a) to an 8v block by simply puttin in a set of 3a pistons?...do the rods also need to be swapped?....thought the two blocks were pretty much identical except for the different piston designs.

it would be very cost effective for me to be able to do this....and get my wife off my a** by getting the block out of our house....i don't know what her problem is


thank you in advance for any input.

[Hurt]

I don't think so, but I'm not entirely sure. Try getting more info on the bore/stroke and whatnot.

[bpederndern]

found this on another forum while searching

"Re: 3A bore and stroke measurments? (TeamTHP)
For all VW in-line 2.0L engines, bore 82.5mm and stroke 92.8mm.
The Audi 3A and the VW 2.0L-16V (9A) blocks are identical, the only difference is the pistons, the 8v pistons are dished and the 16v pistons are flat topped with valve notches. The ABA on the other hand is completely different, the block is 16mm taller, the pistons are different, the rods are longer, the pin diameter is different and the crank has a trigger wheel on it."

other than the pistons and the timing belt pullies they seem the same

[Guidofester]

I wonder if the pistons from a MKIV AEG are the same as 3A pistons. Looking at several sites and I haven't found an answer to this yet. On one site they list different wrist pin sizes so this would be something that you may have to look at.

[Glegor]

I wonder if the pistons from a MKIV AEG are the same as 3A pistons. Looking at several sites and I haven't found an answer to this yet. On one site they list different wrist pin sizes so this would be something that you may have to look at.

Issam Abed probably knows the answer to that, him or another one of those guys..

[Issam Abed]

I wonder if the pistons from a MKIV AEG are the same as 3A pistons. Looking at several sites and I haven't found an answer to this yet. On one site they list different wrist pin sizes so this would be something that you may have to look at.

On paper the specs are pratically the same:
i.e. 82.5mm bore x 92.8mm stroke for use in a 220mm block.
3A uses a 20mm wrist pin and AEG (depending on the year) more than likely uses a 19mm tappered pin.

Also in lehmans terms AEG pistons have no "meat"

[mk2golf14s]

the aeg pistons have a 20mm wrist pin. all of the other mk4 2.0s have 19mm pins. as far as the amount of "meat" the pistons have, what are u planning on doing with them. i have made roughly 300whp on them.

[Guidofester]

the aeg pistons have a 20mm wrist pin. all of the other mk4 2.0s have 19mm pins. as far as the amount of "meat" the pistons have, what are u planning on doing with them. i have made roughly 300whp on them.

What engine block did you use to make this horse power? For my application I have Several 9A blocks and I have several 1.8 8V heads that I would love to play with in my MKI Caddy. This would be more of a daily driver.

So I guess it would be best to contact the popular suppliers for oversized pistons if I go that route!
Wossner, JE & Wiseco. If I can confirm that the AEG Pistons will do the trick I may just go that route.

On another note, What can I expect to pay to get main bearings of a 9A line bored?

[Issam Abed]

the aeg pistons have a 20mm wrist pin. all of the other mk4 2.0s have 19mm pins. as far as the amount of "meat" the pistons have, what are u planning on doing with them. i have made roughly 300whp on them.

AZG uses 20mm...
100% confirmed AEG uses 19mm. I just measured the set here.

[mk2golf14s]

well hope u have the two mixed up because i had a set of aeg's that were def 20mm wrist pin, but just recently i bought a set of azg pistons and they were 19mm wrist pin ( i needed 20mm wrist pin). paid 40 bucks for them and ended up chalking that as a loss. well i just purchased some aeg pistons off of a vortex member because i knew that my aeg's were 20mm. now if they changed them in the same engine code i'm not going to be very happy, but with vw u never know.

[mk2golf14s]

i'm waiting on those piston right now. if they do end up being 19mm pins, i guess i wont be building my motor this weekend.

[mk2golf14s]

i used a aba block, but i'm pretty sure the 9a block is going to be just as strong. i made about 230whp on stock 11:1 16v block with no issues. had the car like that for about a year before i sold it.

[Issam Abed]

well hope u have the two mixed up because i had a set of aeg's that were def 20mm wrist pin, but just recently i bought a set of azg pistons and they were 19mm wrist pin ( i needed 20mm wrist pin). paid 40 bucks for them and ended up chalking that as a loss. well i just purchased some aeg pistons off of a vortex member because i knew that my aeg's were 20mm. now if they changed them in the same engine code i'm not going to be very happy, but with vw u never know.

True except I parted out 60 crate AZG motors over the last 4 years and all were 20mm . You can ask Josh@Techtonicstuning since he has all the pistons and rods

[mk2golf14s]

I must just be unlucky

[mk2golf14s]

just got my aeg pistons and they were indeed 20mm.