Quote:
Originally Posted by stevej37
from C&D
Back at the turn of the 21st century, Saab revealed a supercharged 1.6-liter inline-five engine with a hinged two-piece block. The engine lowered its compression ratio from 14.0:1 to 8.0:1 by pivoting the top of the block, including the cylinders and the head, around a beefy hinge on the intake side. A set of mini connecting rods riding on an eccentric shaft on the exhaust side did the lifting. Since the crankshaft position is fixed, tilting the block’s top changed the combustion-chamber volume and thus the compression ratio. Saab claimed 225 horsepower and a fuel-economy bump of 30 percent over an engine with similar output. Development costs and Saab’s redheaded-stepchild status within GM meant the capital and interest weren’t there to bring the technology to production.
|
I understand all that. But the concept is so simple I wonder why it has not been adopted by Lexus or anyone else interested in VCR. putting two pistons in each connecting rod seems like an overly complicated way to accomplish the same thing. Either Saab wanted too much money for the patent or there is some technical problem with it. I suggest that rocking the the mass of the block back and forth would not happen fast enough to respond to the changes in compression required by a modern computer controlled engine.