VegardPossible the best engine to equip the Mk2 Syncro with to keep good balance in the car. From approx 300 and up to 700 hp. this engine will do the job.
I will share the information I have, and if someone have inputs or questions they are most welcome.
An engine project always starts with choosing block, crank and cylinderhead. For Syncros there are some limitations due to bolt holes in the block. Chris has described it in this thread:
http://www.vwsyncro.co.uk/data/forums/topic.asp?TOPIC_ID=981
There are two main types of blocks, the 220 mm block height and the taller 236 mm. For turbo use it’s a must to have under piston oil-squirters to spray oil under the pistons. All blocks described here have the oil-squirters.
For our purpose the 9A block from the Passat GT 16v engine is the best of the 220 mm high blocks. It’s a 2.0 litre, and it’s called “bubble block”. This because of the extra space for the rods in the lower part of the block. The stroke is 92.8 mm and the bore is 82.5 mm. Connecting rod length is 144 mm.
The 1.8 liter KR and PL blocks don’t have the needed bolt holes for the angle drive. The only 1.8-block that can be used unmodified is the PG from the G60 engine. The stroke is 86.4 mm and the bore is 81 mm. Connecting rod length is 144 mm. The block can be modified to accept 92.8 crankshaft if metal is removed in the bottom end of each cylinder to give space for the rods.
The tall blocks are the Mk3 Gti, the Mk3 Gti 16v (ABF) and the 1.9 l. Tdk/Tdi engine. The two petrol engines have 92.8 mm. stroke, 82.5 mm. bore and 159 mm, connecting rods. The diesel engines have 95.5 mm. stroke and a narrow bore. They can be rebored to 81.5 mm. to 82.5 mm. or even bigger, my choice is 81.5 mm. due to durability.
There are two stock VAG head gaskets that can be used. The G60 cylinderhead gasket is a 3 layers steel gasket. Or this one from Summit Racing: http://store.summitracing.com/partdetail.asp?part=FEL%2D26182PT&FROM=MG[/QUOTE]
For the ABF engine there are two different VAG gaskets. One of them is a 3 layers steel gasket. That’s the one. Elring part# 627.810 is a good alternative.
http://e-kat.elring.de/de/5220CB00A8157A09BFFF80494CE9E6513.srv?dlg=CtrDefault&action=SetJavaVersion11&java13=true
Summit Racing has a good gasket for 82,5 bore:
http://store.summitracing.com/partdetail.asp?part=FEL%2D26164PT&N=700+4294907729+4294907728+4294924761+4294925237+115&autoview=sku