Case view of VW Type 4 fuel injected engine case. Case is used in all 1.7L, 1.8L and 2L Porsche 914, VW 411 and 412 engines. There are essentially two types of Type 4 Engine Cases! Fuel Injected and Carborated!
The VW Bus use the carb version in 1972 Bus and called it a Type 2 Case... the VW Bus had the carb setup... but was the same case as the carborated Type 4 Case!
The Type 4 Case is an all Aluminum Alloy case... and weights 14lb heavier then the Type 1 case. It is a very strong and robust case and seldom needs to be align bored at a major rebuild

The Type 1 case was an Aluminum Alloy case with a high content of magnesium which weakened the case and presented problems when it came to holding design torque as well as cracking behind the #3 cylinder and head bolts pulling out. This case was ok in the VW cars but... the use in aircraft engines is another story especially when used with the stroker engines. The engine builders had to do some major mods... such as welding a patch behind the #3 cylinder, installing inserts for the heads bolts to keep them from pulling out. The Type 1 engine had to have the case align bored at each major rebuild due to the pounding out the crankshaft journals... especially the stroker engines. Now you have a choice of buying a new Type 1 all Aluminum case which of course will be heavier then the mag/alum case but a lot stronger and able to hold torque.