Quote:
Originally Posted by sarguy01
Instead of killing two cylinders, why can't one destroke an engine and not have to mess around with the balance, valves, etc, etc??
Would the difference in gas mileage in between say, a 2.0L and a 1.5L be significant enough to pay for the cost of the crank and other machining required?
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probably not, unless you found a match with interchangeable parts to make the swap work.
For example, a 2.0L ford escort/focus zetec and spi motor can be destroked to 1.7L by using a 80's ford escort CVH 1.6 crank (i forgot what they used for rods)
I do have another thought on this... the reason for decreasing motor displacement is to operate the motor at a higher load so there is less pumping losses, so instead of cylinder disabling or de-stroking a motor, how about grinding a cam that takes advantage of the atkinson cycle for the reduction of pumping losses.
What I'm referring to is have the intake duration of the cam moved so that the intake valve stays open a percentage of the compression stroke to reduce engine vacuum and the air/fuel cylinder fill that enters the cylinder prior to compression/ignition, making the engine act as a smaller displacement motor.
I'm thunking of trying this with my 2.3 mustang... milling the head for high compression and adding a custom grind camshaft that will promote a late closing of the intake valves.
How this affects the operation of the vacuum dependent accessories (brakes, cruise control, hvac vent doors) remain a mystery. I have located a manual brake conversion kit ($70) in case it does affect brake boost. I may have to run a small vacuum pump to control the other items.