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Old 09-11-2010, 01:42 PM   #8 (permalink)
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Originally Posted by Frank Lee View Post
The thing is to not have pumping losses. That means no air in/out of the cyl. That means NO valves working in that cyl. Yes I think removal of the unused pistons/rods is vital to reduce the internal friction. The unused crank journal oil holes will need to be plugged somehow. Disabling injectors alone does nothing good.

I've considered this mod for quite a long time. Only reasons I haven't done it already are 1) Inertia... laziness 2) My M.O.: If it ain't broke, don't fix it 3) The car gets pretty decent fe already.
trying to remove piston an rod and get it balanced is not worth it .
cars that have cylinder deactivation still have piston going up and down but modify the value opening with rockers .
Most disable the intake valve operation .

Here info on Honda V6 modes

VCM Operation
""To help improve the fuel efficiency of the V-6 engine available with the 5-speed automatic transmission, a new generation of Honda's VCM is used. This is the first application of VCM on a non-hybrid Accord model. Unlike previous VCM systems that switched between three- and six-cylinder operation, the Accord's system can operate on three, four or all six cylinders.

During startup, acceleration or when climbing hills - any time high power output is required - the engine operates on all six cylinders. During moderate speed cruising and at low engine loads, the system operates just one bank of three cylinders. For moderate acceleration, higher-speed cruising and mild hills, the engine operates on four cylinders.

With three operating modes, the VCM system can finely tailor the working displacement of the engine to match the driving requirements from moment to moment. Since the system automatically closes both the intake and exhaust valves of the cylinders that are not used, pumping losses associated with intake and exhaust are eliminated and fuel economy gets a further boost. The VCM system combines maximum performance and maximum fuel economy - two characteristics that don't typically coexist in conventional engines.

VCM deactivates specific cylinders by using the VTEC (Variable Valve-Timing and Lift Electronic Control) system to close the intake and exhaust valves while simultaneously the Powertrain Control Module cuts fuel to those cylinders. When operating on three cylinders, the rear cylinder bank is shut down. When running on four cylinders, the left and center cylinders of the front bank operate, and the right and center cylinders of the rear bank operate.

The spark plugs continue to fire in inactive cylinders to minimize plug temperature loss and prevent fouling induced from incomplete combustion during cylinder re-activation.""

So the easest would be remove the 2 rockers on the cylinders that want to no fire and unplug injector .
Another way would be remove intake rocker (intake valve always closed) , then on exhaust adjust lash so valve is never closed and if you wanted make a header with the 2 disabled exhaust ports being connected (not going out the tail pipe) the exhaust would just go back and forth in the dead cylinders. honda claims no pumping losses with both valves closed , hmm .
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