Theone61636,
Simple. The carmakers here use to take every last breath of anything. For this, brazilian built galaxies had the Y block engine up to 1976, GM used the venerable 261 up to 1978 in all gasoline powered commercial vehicles, and in 1994, German Opel quit making the 3.0L L6 engine used in Opel Omega, they just did not hesitate even one moment and shaped a 12 port head and a multi point fuel injection system for the old 250. It's somewhat complex, in fact almost a new engine if compared to the old school 250. Large one piece rear main seal like the ones found on latter models GM L4 181 cid engine, the valvegear is net lash, the system is distributorless, the cam has a special positioning sensor. The single most interesting part is the head. It's desing still allows the use of non-efi manifolds, although the intake ports are quite small, but placed much higher on the head, giving a performance advantege. There is a hype here that it was a desing made by Lotus. Truth or not, it was the same time that GM had owned Lotus and had made by them the LT5 Corvette engine, the Ilmor Indy engine and some other details. I'm quite interested in getting one of these heads and cutting it all apart to see the porting possibilities. And there is a super interesting split cast iron exaust manifold. Extremely well cast, decent flow, but seems a tight fit on pass cars. At least on our opalas. I have some pics of this efi 250. If you want some, just let me know and I can mail you them. The efi engine revs freely up to 4500rpm, and can go up to 5500, after that it does cuts off. Incredibly it does performs poorly when compared to the german 3.0 L engine. The same car equipped with both engines shows 10 kph more on top speed with the 3.0, the 0-60 is close, and fuel economy is lousy in the 250.
