specs on vdub motors.

[shannon ekermans]

Engine Key
Tag Description
1.7 VW 8v EN (early '80s Rabbit, Scirocco) (rare and old style non applicable)
1.8 VW 10:1 8v (about a million engine codes, use HT, RD or PF)
1.9 1.9 diesel (unclear if this is new or old style)
16v VW 1.8 16v (mid-late '80s GTi, Scirocco), engine code PL
20v VW/Audi 1.8t 5-valves per cylinder, Audi A4, neue-Beetle &c (got codes?)
3A Audi 2.0 8v "bubble block" (late '80s Audi 4k/80)
9A VW 2.0 l 16v (early '90s GTi)
G60 VW Corrado G60 1.8 supercharged, engine code PG
MC Audi 2.2 5 cyl turbo (mid-late '80s Audi 5kt and 5ktq; forged pistons)

Dimensions
Tag Bore Stroke Disp Rod Journal Rod Length Wrist Pin Compression Height Piston Dish Block Height CR
1.7 79.5 86.4 1715 46 136 22 37.5 21 220 8.2:1 (old style non applicable)
G60 81.0 86.4 1781 48 136 22 39.5 25 220 8:1 (rare here) same crank as CTI Forged
MC 81.0 86.4 2226 46 136 22 41.5 26 220 7.8:1 pistons can be used for low comp 8v build (expensive)
1.8 81.0 86.4 1781 48 144 20 32.2 10 220 10:1
16v 81.0 86.4 1781 48 144 20 33.4 -5 220 10:1
20v 81.0 86.4 1781 48 144 20 32.8 0.0 220 9.15:1

Tag Bore Stroke Disp Rod Journal Rod Length Wrist Pin Compression Height Piston Dish Block Height CR
3A 82.5 92.8 1984 48 144 20 ? 15.5 220 10.5:1
9A 82.5 92.8 1984 48 144 20 30.2 -4 220 10.8:1
2E 82.5 92.8 1984 48 159 20 30.9 14.61 236 10:1

what can be determined from all this info is almost every new style shortblock(being 220mmblock) motor can fit any newstyle crank including the 2e. therefore the size motor u decide to build is dependant on the crank and the pistons as they are almost all interchangeable.

a few common options

1.4 or 1.6 to 1.8 motor 8v

swap out 1800 crank and 1800 pistons keep conrods and head.
if its a 1.4 then the 40mm intake head is suggested.

1.4 or 1.6 to 2.0 8v motor

swap out 2.0 crank keep 144mm rods and use kombi 2.6 pistons.
minor work needs to be done to get this to work properly. here is a link
http://www.vwclub.co.za/phpbb3/viewtopi ... NK#p676862
for 1.4 motor the big valve head is also suggested as is above.

1.8 low comp 8v build

shortblock with 1.8 crank 14mm rods and kombi 2.6 pistons.
the shorter compression height on the 2.6 piston means that it will sit below the deck of the block
effectively lowering compression.
the block will need to be decked in order to get the required compression.

2.1 build 8 or 16v
a longblock is required for this build as the 95.5mm crank will not fit in the shortblock. the diesel crank with 159mm rods is the base point. the combination for piston is determined by which head u decide to use and your required compression ratio.i am not to familiar with this and so i will leave this up to u as to how u decide to use this info.

2.0 low comp 16v build

there are 2 options available when it comes to building a 2.0 turbo build
1) short block. use 2.0 crank with 144mm rods and 2.6 kombi pistons valve reliefs should be cut into the pistons in order to keep clearance with the valves. of the 16v head. this combo should yield in the region of 8.5-1 comp.

2)longblock(236mm block height) use complete 2.0 sub assembly. crank rods and block. with the 16v head i believe no valve relief needs to be cut into the pistons but i am not 100% sure about this.

please correct me if i am wrong.this info is merely for informational purposes and is to be used as a guideline. it should be used to determine what is possible with what u have already available and what might be needed.

[Maxx600RR]

very informative. Bit much for a early morning read
How goes the race car build ?

[panic-mechanic]

2L lonbglblock 8v + 16v head does need small valve reliefs cut. They don't have to be massive. Only about 2-3 mm deep.

[shannon ekermans]

i know its not 100% accurate when it comes to what pulleys etc that need to be used with which motor but if anyone is willing to post a build link etc eg 2.1 longblock then it can be used to show guys what to do instead of having to keep saying it over and over.

[Mack_1]

I am currently rebuilding my 5cyl AFU engine and want to fit good quality pistons e.g. Nüral, KS or Mahle but it seems these pistons are nla from these suppliers. Can anyone confirm the Compression Height of the 2.3 AFU piston? I may be able to get Nürals from overseas but need to confirm the Comp Height first and I do not have the old pistons with me.

[PapaJo]

I am currently rebuilding my 5cyl AFU engine and want to fit good quality pistons e.g. Nüral, KS or Mahle but it seems these pistons are nla from these suppliers. Can anyone confirm the Compression Height of the 2.3 AFU piston? I may be able to get Nürals from overseas but need to confirm the Comp Height first and I do not have the old pistons with me.

11 year old thread revival.

@Mack_1

Take a vernier and measure the pistons you have in block to determine the compression height. Measure from top of piston to center of gudgeon pin and that will be the piston compression height. If you are not to sure about exact centre of gudgeon pin, measure from top of piston up to top of gudgeon pin, then you measure the gudgeon pin diameter, divide the gudgeon pin diameter by 2, add this value to the measured value of piston from top to top of gudgeon pin hole on piston.

Example: top of piston to top of gudgeon pin hole measure 22,2, gudgeon pin is 20mm, 1/2 gudgeon pin size is (20/2)=10mm, Add 22,2 mm + 10mm = 32,2mm compression height.

Note: Some pistons have a squish area on the top of piston or has dome pistons that is higher than the outside skirt of the piston, so take note of that on your current pistons when searching for replacement pistons.

Other than that, you can take one of your current pistons to an engineering shop or even a spares shop and they should be able to assist getting the measurements for you.

[Mack_1]

Feedback appreciated. Had to settle for Arco pistons.